Package org.apache.commons.io

Class IOUtils

java.lang.Object
org.apache.commons.io.IOUtils
public class IOUtils extends Object
General IO stream manipulation utilities.

This class provides static utility methods for input/output operations.

  • [Deprecated] closeQuietly - these methods close a stream ignoring nulls and exceptions
  • toXxx/read - these methods read data from a stream
  • write - these methods write data to a stream
  • copy - these methods copy all the data from one stream to another
  • contentEquals - these methods compare the content of two streams

The byte-to-char methods and char-to-byte methods involve a conversion step. Two methods are provided in each case, one that uses the platform default encoding and the other which allows you to specify an encoding. You are encouraged to always specify an encoding because relying on the platform default can lead to unexpected results, for example when moving from development to production.

All the methods in this class that read a stream are buffered internally. This means that there is no cause to use a BufferedInputStream or BufferedReader. The default buffer size of 4K has been shown to be efficient in tests.

The various copy methods all delegate the actual copying to one of the following methods:

For example, copy(InputStream, OutputStream) calls copyLarge(InputStream, OutputStream) which calls copy(InputStream, OutputStream, int) which creates the buffer and calls copyLarge(InputStream, OutputStream, byte[]).

Applications can re-use buffers by using the underlying methods directly. This may improve performance for applications that need to do a lot of copying.

Wherever possible, the methods in this class do not flush or close the stream. This is to avoid making non-portable assumptions about the streams' origin and further use. Thus the caller is still responsible for closing streams after use.

Origin of code: Excalibur.

  • Field Details

    • EMPTY_BYTE_ARRAY

      private static final byte[] EMPTY_BYTE_ARRAY

    • DEFAULT_BUFFER_SIZE

      public static final int DEFAULT_BUFFER_SIZE
      The default buffer size (8192) to use in copy methods.
      See Also:

    • DIR_SEPARATOR

      public static final char DIR_SEPARATOR
      The system directory separator character.

    • DIR_SEPARATOR_UNIX

      public static final char DIR_SEPARATOR_UNIX
      The Unix directory separator character.
      See Also:

    • DIR_SEPARATOR_WINDOWS

      public static final char DIR_SEPARATOR_WINDOWS
      The Windows directory separator character.
      See Also:

    • EOF

      public static final int EOF
      Represents the end-of-file (or stream).
      Since:
      2.5 (made public)
      See Also:

    • LINE_SEPARATOR

      @Deprecated public static final String LINE_SEPARATOR
      Deprecated.
      Use System.lineSeparator().
      The system line separator string.

    • LINE_SEPARATOR_UNIX

      public static final String LINE_SEPARATOR_UNIX
      The Unix line separator string.
      See Also:

    • LINE_SEPARATOR_WINDOWS

      public static final String LINE_SEPARATOR_WINDOWS
      The Windows line separator string.
      See Also:

    • SKIP_BYTE_BUFFER

      private static final byte[] SKIP_BYTE_BUFFER
      The default buffer to use for the skip() methods.

    • SKIP_CHAR_BUFFER

      private static char[] SKIP_CHAR_BUFFER

  • Constructor Details

    • IOUtils

      public IOUtils()
      Instances should NOT be constructed in standard programming.

  • Method Details

    • buffer

      public static BufferedInputStream buffer(InputStream inputStream)
      Returns the given InputStream if it is already a BufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.
      Parameters:
      inputStream - the InputStream to wrap or return (not null)
      Returns:
      the given InputStream or a new BufferedInputStream for the given InputStream
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • buffer

      public static BufferedInputStream buffer(InputStream inputStream, int size)
      Returns the given InputStream if it is already a BufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.
      Parameters:
      inputStream - the InputStream to wrap or return (not null)
      size - the buffer size, if a new BufferedInputStream is created.
      Returns:
      the given InputStream or a new BufferedInputStream for the given InputStream
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • buffer

      public static BufferedOutputStream buffer(OutputStream outputStream)
      Returns the given OutputStream if it is already a BufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream.
      Parameters:
      outputStream - the OutputStream to wrap or return (not null)
      Returns:
      the given OutputStream or a new BufferedOutputStream for the given OutputStream
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • buffer

      public static BufferedOutputStream buffer(OutputStream outputStream, int size)
      Returns the given OutputStream if it is already a BufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream.
      Parameters:
      outputStream - the OutputStream to wrap or return (not null)
      size - the buffer size, if a new BufferedOutputStream is created.
      Returns:
      the given OutputStream or a new BufferedOutputStream for the given OutputStream
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • buffer

      public static BufferedReader buffer(Reader reader)
      Returns the given reader if it is already a BufferedReader, otherwise creates a BufferedReader from the given reader.
      Parameters:
      reader - the reader to wrap or return (not null)
      Returns:
      the given reader or a new BufferedReader for the given reader
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • buffer

      public static BufferedReader buffer(Reader reader, int size)
      Returns the given reader if it is already a BufferedReader, otherwise creates a BufferedReader from the given reader.
      Parameters:
      reader - the reader to wrap or return (not null)
      size - the buffer size, if a new BufferedReader is created.
      Returns:
      the given reader or a new BufferedReader for the given reader
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • buffer

      public static BufferedWriter buffer(Writer writer)
      Returns the given Writer if it is already a BufferedWriter, otherwise creates a BufferedWriter from the given Writer.
      Parameters:
      writer - the Writer to wrap or return (not null)
      Returns:
      the given Writer or a new BufferedWriter for the given Writer
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • buffer

      public static BufferedWriter buffer(Writer writer, int size)
      Returns the given Writer if it is already a BufferedWriter, otherwise creates a BufferedWriter from the given Writer.
      Parameters:
      writer - the Writer to wrap or return (not null)
      size - the buffer size, if a new BufferedWriter is created.
      Returns:
      the given Writer or a new BufferedWriter for the given Writer
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5

    • close

      public static void close(Closeable closeable) throws IOException
      Closes the given Closeable as a null-safe operation.
      Parameters:
      closeable - The resource to close, may be null.
      Throws:
      IOException - if an I/O error occurs.
      Since:
      2.7

    • close

      public static void close(Closeable... closeables) throws IOException
      Closes the given Closeable as a null-safe operation.
      Parameters:
      closeables - The resource(s) to close, may be null.
      Throws:
      IOException - if an I/O error occurs.
      Since:
      2.8.0

    • close

      public static void close(Closeable closeable, IOConsumer<IOException> consumer) throws IOException
      Closes the given Closeable as a null-safe operation.
      Parameters:
      closeable - The resource to close, may be null.
      consumer - Consume the IOException thrown by Closeable.close().
      Throws:
      IOException - if an I/O error occurs.
      Since:
      2.7

    • close

      public static void close(URLConnection conn)
      Closes a URLConnection.
      Parameters:
      conn - the connection to close.
      Since:
      2.4

    • closeQuietly

      @Deprecated public static void closeQuietly(Closeable closeable)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes a Closeable unconditionally.

      Equivalent to Closeable.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

       Closeable closeable = null;
 try {
     closeable = new FileReader("foo.txt");
     // process closeable
     closeable.close();
 } catch (Exception e) {
     // error handling
 } finally {
     IOUtils.closeQuietly(closeable);
 }

      Closing all streams: 

       try {
     return IOUtils.copy(inputStream, outputStream);
 } finally {
     IOUtils.closeQuietly(inputStream);
     IOUtils.closeQuietly(outputStream);
 }
      Parameters:
      closeable - the objects to close, may be null or already closed
      Since:
      2.0
      See Also:

    • closeQuietly

      @Deprecated public static void closeQuietly(Closeable... closeables)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes a Closeable unconditionally.

      Equivalent to Closeable.close(), except any exceptions will be ignored.

      This is typically used in finally blocks to ensure that the closeable is closed even if an Exception was thrown before the normal close statement was reached.
      It should not be used to replace the close statement(s) which should be present for the non-exceptional case.
      It is only intended to simplify tidying up where normal processing has already failed and reporting close failure as well is not necessary or useful.

      Example code: 

       Closeable closeable = null;
 try {
     closeable = new FileReader("foo.txt");
     // processing using the closeable; may throw an Exception
     closeable.close(); // Normal close - exceptions not ignored
 } catch (Exception e) {
     // error handling
 } finally {
     IOUtils.closeQuietly(closeable); // In case normal close was skipped due to Exception
 }

      Closing all streams: 

       try {
     return IOUtils.copy(inputStream, outputStream);
 } finally {
     IOUtils.closeQuietly(inputStream, outputStream);
 }
      Parameters:
      closeables - the objects to close, may be null or already closed
      Since:
      2.5
      See Also:

    • closeQuietly

      public static void closeQuietly(Closeable closeable, Consumer<IOException> consumer)
      Closes the given Closeable as a null-safe operation while consuming IOException by the given consumer.
      Parameters:
      closeable - The resource to close, may be null.
      consumer - Consumes the IOException thrown by Closeable.close().
      Since:
      2.7

    • closeQuietly

      @Deprecated public static void closeQuietly(InputStream input)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes an InputStream unconditionally.

      Equivalent to InputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

         byte[] data = new byte[1024];
   InputStream in = null;
   try {
       in = new FileInputStream("foo.txt");
       in.read(data);
       in.close(); //close errors are handled
   } catch (Exception e) {
       // error handling
   } finally {
       IOUtils.closeQuietly(in);
   }
      Parameters:
      input - the InputStream to close, may be null or already closed
      See Also:

    • closeQuietly

      @Deprecated public static void closeQuietly(OutputStream output)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes an OutputStream unconditionally.

      Equivalent to OutputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

       byte[] data = "Hello, World".getBytes();

 OutputStream out = null;
 try {
     out = new FileOutputStream("foo.txt");
     out.write(data);
     out.close(); //close errors are handled
 } catch (IOException e) {
     // error handling
 } finally {
     IOUtils.closeQuietly(out);
 }
      Parameters:
      output - the OutputStream to close, may be null or already closed
      See Also:

    • closeQuietly

      @Deprecated public static void closeQuietly(Reader input)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes an Reader unconditionally.

      Equivalent to Reader.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

         char[] data = new char[1024];
   Reader in = null;
   try {
       in = new FileReader("foo.txt");
       in.read(data);
       in.close(); //close errors are handled
   } catch (Exception e) {
       // error handling
   } finally {
       IOUtils.closeQuietly(in);
   }
      Parameters:
      input - the Reader to close, may be null or already closed
      See Also:

    • closeQuietly

      @Deprecated public static void closeQuietly(Selector selector)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes a Selector unconditionally.

      Equivalent to Selector.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

         Selector selector = null;
   try {
       selector = Selector.open();
       // process socket

   } catch (Exception e) {
       // error handling
   } finally {
       IOUtils.closeQuietly(selector);
   }
      Parameters:
      selector - the Selector to close, may be null or already closed
      Since:
      2.2
      See Also:

    • closeQuietly

      @Deprecated public static void closeQuietly(ServerSocket serverSocket)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes a ServerSocket unconditionally.

      Equivalent to ServerSocket.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

         ServerSocket socket = null;
   try {
       socket = new ServerSocket();
       // process socket
       socket.close();
   } catch (Exception e) {
       // error handling
   } finally {
       IOUtils.closeQuietly(socket);
   }
      Parameters:
      serverSocket - the ServerSocket to close, may be null or already closed
      Since:
      2.2
      See Also:

    • closeQuietly

      @Deprecated public static void closeQuietly(Socket socket)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes a Socket unconditionally.

      Equivalent to Socket.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

         Socket socket = null;
   try {
       socket = new Socket("http://www.foo.com/", 80);
       // process socket
       socket.close();
   } catch (Exception e) {
       // error handling
   } finally {
       IOUtils.closeQuietly(socket);
   }
      Parameters:
      socket - the Socket to close, may be null or already closed
      Since:
      2.0
      See Also:

    • closeQuietly

      @Deprecated public static void closeQuietly(Writer output)
      Deprecated.
      As of 2.6 deprecated without replacement. Please use the try-with-resources statement or handle suppressed exceptions manually.
      Closes an Writer unconditionally.

      Equivalent to Writer.close(), except any exceptions will be ignored. This is typically used in finally blocks.

      Example code: 

         Writer out = null;
   try {
       out = new StringWriter();
       out.write("Hello World");
       out.close(); //close errors are handled
   } catch (Exception e) {
       // error handling
   } finally {
       IOUtils.closeQuietly(out);
   }
      Parameters:
      output - the Writer to close, may be null or already closed
      See Also:

    • consume

      public static long consume(InputStream input) throws IOException
      Consumes bytes from a InputStream and ignores them.

      The buffer size is given by DEFAULT_BUFFER_SIZE.

      Parameters:
      input - the InputStream to read from
      Returns:
      the number of bytes copied. or 0 if input is null.
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.8.0

    • contentEquals

      public static boolean contentEquals(InputStream input1, InputStream input2) throws IOException
      Compares the contents of two Streams to determine if they are equal or not.

      This method buffers the input internally using BufferedInputStream if they are not already buffered.

      Parameters:
      input1 - the first stream
      input2 - the second stream
      Returns:
      true if the content of the streams are equal or they both don't exist, false otherwise
      Throws:
      NullPointerException - if either input is null
      IOException - if an I/O error occurs

    • contentEquals

      public static boolean contentEquals(Reader input1, Reader input2) throws IOException
      Compares the contents of two Readers to determine if they are equal or not.

      This method buffers the input internally using BufferedReader if they are not already buffered.

      Parameters:
      input1 - the first reader
      input2 - the second reader
      Returns:
      true if the content of the readers are equal or they both don't exist, false otherwise
      Throws:
      NullPointerException - if either input is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • contentEqualsIgnoreEOL

      public static boolean contentEqualsIgnoreEOL(Reader input1, Reader input2) throws IOException
      Compares the contents of two Readers to determine if they are equal or not, ignoring EOL characters.

      This method buffers the input internally using BufferedReader if they are not already buffered.

      Parameters:
      input1 - the first reader
      input2 - the second reader
      Returns:
      true if the content of the readers are equal (ignoring EOL differences), false otherwise
      Throws:
      NullPointerException - if either input is null
      IOException - if an I/O error occurs
      Since:
      2.2

    • copy

      public static int copy(InputStream input, OutputStream output) throws IOException
      Copies bytes from an InputStream to an OutputStream.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Large streams (over 2GB) will return a bytes copied value of -1 after the copy has completed since the correct number of bytes cannot be returned as an int. For large streams use the copyLarge(InputStream, OutputStream) method.

      Parameters:
      input - the InputStream to read from
      output - the OutputStream to write to
      Returns:
      the number of bytes copied, or -1 if > Integer.MAX_VALUE, or 0 if input is null.
      Throws:
      NullPointerException - if the output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • copy

      public static long copy(InputStream input, OutputStream output, int bufferSize) throws IOException
      Copies bytes from an InputStream to an OutputStream using an internal buffer of the given size.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from
      output - the OutputStream to write to
      bufferSize - the bufferSize used to copy from the input to the output
      Returns:
      the number of bytes copied. or 0 if input is null.
      Throws:
      NullPointerException - if the output is null
      IOException - if an I/O error occurs
      Since:
      2.5

    • copy

      @Deprecated public static void copy(InputStream input, Writer output) throws IOException
      Deprecated.
      2.5 use copy(InputStream, Writer, Charset) instead
      Copies bytes from an InputStream to chars on a Writer using the default character encoding of the platform.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      This method uses InputStreamReader.

      Parameters:
      input - the InputStream to read from
      output - the Writer to write to
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • copy

      public static void copy(InputStream input, Writer output, Charset inputCharset) throws IOException
      Copies bytes from an InputStream to chars on a Writer using the specified character encoding.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      This method uses InputStreamReader.

      Parameters:
      input - the InputStream to read from
      output - the Writer to write to
      inputCharset - the charset to use for the input stream, null means platform default
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • copy

      public static void copy(InputStream input, Writer output, String inputCharsetName) throws IOException
      Copies bytes from an InputStream to chars on a Writer using the specified character encoding.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Character encoding names can be found at IANA.

      This method uses InputStreamReader.

      Parameters:
      input - the InputStream to read from
      output - the Writer to write to
      inputCharsetName - the name of the requested charset for the InputStream, null means platform default
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • copy

      public static long copy(Reader input, Appendable output) throws IOException
      Copies chars from a Reader to a Appendable.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Large streams (over 2GB) will return a chars copied value of -1 after the copy has completed since the correct number of chars cannot be returned as an int. For large streams use the copyLarge(Reader, Writer) method.

      Parameters:
      input - the Reader to read from
      output - the Appendable to write to
      Returns:
      the number of characters copied, or -1 if > Integer.MAX_VALUE
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.7

    • copy

      public static long copy(Reader input, Appendable output, CharBuffer buffer) throws IOException
      Copies chars from a Reader to an Appendable.

      This method uses the provided buffer, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      output - the Appendable to write to
      buffer - the buffer to be used for the copy
      Returns:
      the number of characters copied
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.7

    • copy

      @Deprecated public static void copy(Reader input, OutputStream output) throws IOException
      Deprecated.
      2.5 use copy(Reader, OutputStream, Charset) instead
      Copies chars from a Reader to bytes on an OutputStream using the default character encoding of the platform, and calling flush.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Due to the implementation of OutputStreamWriter, this method performs a flush.

      This method uses OutputStreamWriter.

      Parameters:
      input - the Reader to read from
      output - the OutputStream to write to
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • copy

      public static void copy(Reader input, OutputStream output, Charset outputCharset) throws IOException
      Copies chars from a Reader to bytes on an OutputStream using the specified character encoding, and calling flush.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Due to the implementation of OutputStreamWriter, this method performs a flush.

      This method uses OutputStreamWriter.

      Parameters:
      input - the Reader to read from
      output - the OutputStream to write to
      outputCharset - the charset to use for the OutputStream, null means platform default
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • copy

      public static void copy(Reader input, OutputStream output, String outputCharsetName) throws IOException
      Copies chars from a Reader to bytes on an OutputStream using the specified character encoding, and calling flush.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Character encoding names can be found at IANA.

      Due to the implementation of OutputStreamWriter, this method performs a flush.

      This method uses OutputStreamWriter.

      Parameters:
      input - the Reader to read from
      output - the OutputStream to write to
      outputCharsetName - the name of the requested charset for the OutputStream, null means platform default
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • copy

      public static int copy(Reader input, Writer output) throws IOException
      Copies chars from a Reader to a Writer.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Large streams (over 2GB) will return a chars copied value of -1 after the copy has completed since the correct number of chars cannot be returned as an int. For large streams use the copyLarge(Reader, Writer) method.

      Parameters:
      input - the Reader to read from
      output - the Writer to write to
      Returns:
      the number of characters copied, or -1 if > Integer.MAX_VALUE
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • copyLarge

      public static long copyLarge(InputStream input, OutputStream output) throws IOException
      Copies bytes from a large (over 2GB) InputStream to an OutputStream.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      The buffer size is given by DEFAULT_BUFFER_SIZE.

      Parameters:
      input - the InputStream to read from
      output - the OutputStream to write to
      Returns:
      the number of bytes copied. or 0 if input is null.
      Throws:
      NullPointerException - if the output is null
      IOException - if an I/O error occurs
      Since:
      1.3

    • copyLarge

      public static long copyLarge(InputStream input, OutputStream output, byte[] buffer) throws IOException
      Copies bytes from a large (over 2GB) InputStream to an OutputStream.

      This method uses the provided buffer, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from
      output - the OutputStream to write to
      buffer - the buffer to use for the copy
      Returns:
      the number of bytes copied. or 0 if input is null.
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.2

    • copyLarge

      public static long copyLarge(InputStream input, OutputStream output, long inputOffset, long length) throws IOException
      Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

      The buffer size is given by DEFAULT_BUFFER_SIZE.
      Parameters:
      input - the InputStream to read from
      output - the OutputStream to write to
      inputOffset - : number of bytes to skip from input before copying -ve values are ignored
      length - : number of bytes to copy. -ve means all
      Returns:
      the number of bytes copied
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.2

    • copyLarge

      public static long copyLarge(InputStream input, OutputStream output, long inputOffset, long length, byte[] buffer) throws IOException
      Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.

      This method uses the provided buffer, so there is no need to use a BufferedInputStream.

      Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

      Parameters:
      input - the InputStream to read from
      output - the OutputStream to write to
      inputOffset - : number of bytes to skip from input before copying -ve values are ignored
      length - : number of bytes to copy. -ve means all
      buffer - the buffer to use for the copy
      Returns:
      the number of bytes copied
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.2

    • copyLarge

      public static long copyLarge(Reader input, Writer output) throws IOException
      Copies chars from a large (over 2GB) Reader to a Writer.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      The buffer size is given by DEFAULT_BUFFER_SIZE.

      Parameters:
      input - the Reader to read from
      output - the Writer to write to
      Returns:
      the number of characters copied
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      1.3

    • copyLarge

      public static long copyLarge(Reader input, Writer output, char[] buffer) throws IOException
      Copies chars from a large (over 2GB) Reader to a Writer.

      This method uses the provided buffer, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      output - the Writer to write to
      buffer - the buffer to be used for the copy
      Returns:
      the number of characters copied
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.2

    • copyLarge

      public static long copyLarge(Reader input, Writer output, long inputOffset, long length) throws IOException
      Copies some or all chars from a large (over 2GB) InputStream to an OutputStream, optionally skipping input chars.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      The buffer size is given by DEFAULT_BUFFER_SIZE.

      Parameters:
      input - the Reader to read from
      output - the Writer to write to
      inputOffset - : number of chars to skip from input before copying -ve values are ignored
      length - : number of chars to copy. -ve means all
      Returns:
      the number of chars copied
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.2

    • copyLarge

      public static long copyLarge(Reader input, Writer output, long inputOffset, long length, char[] buffer) throws IOException
      Copies some or all chars from a large (over 2GB) InputStream to an OutputStream, optionally skipping input chars.

      This method uses the provided buffer, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      output - the Writer to write to
      inputOffset - : number of chars to skip from input before copying -ve values are ignored
      length - : number of chars to copy. -ve means all
      buffer - the buffer to be used for the copy
      Returns:
      the number of chars copied
      Throws:
      NullPointerException - if the input or output is null
      IOException - if an I/O error occurs
      Since:
      2.2

    • length

      public static int length(byte[] array)
      Returns the length of the given array in a null-safe manner.
      Parameters:
      array - an array or null
      Returns:
      the array length -- or 0 if the given array is null.
      Since:
      2.7

    • length

      public static int length(char[] array)
      Returns the length of the given array in a null-safe manner.
      Parameters:
      array - an array or null
      Returns:
      the array length -- or 0 if the given array is null.
      Since:
      2.7

    • length

      public static int length(CharSequence csq)
      Returns the length of the given CharSequence in a null-safe manner.
      Parameters:
      csq - a CharSequence or null
      Returns:
      the CharSequence length -- or 0 if the given CharSequence is null.
      Since:
      2.7

    • length

      public static int length(Object[] array)
      Returns the length of the given array in a null-safe manner.
      Parameters:
      array - an array or null
      Returns:
      the array length -- or 0 if the given array is null.
      Since:
      2.7

    • lineIterator

      public static LineIterator lineIterator(InputStream input, Charset charset) throws IOException
      Returns an Iterator for the lines in an InputStream, using the character encoding specified (or default encoding if null).

      LineIterator holds a reference to the open InputStream specified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by closing the stream directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator).

      The recommended usage pattern is: 

       try {
   LineIterator it = IOUtils.lineIterator(stream, charset);
   while (it.hasNext()) {
     String line = it.nextLine();
     /// do something with line
   }
 } finally {
   IOUtils.closeQuietly(stream);
 }
      Parameters:
      input - the InputStream to read from, not null
      charset - the charset to use, null means platform default
      Returns:
      an Iterator of the lines in the reader, never null
      Throws:
      IllegalArgumentException - if the input is null
      IOException - if an I/O error occurs, such as if the encoding is invalid
      Since:
      2.3

    • lineIterator

      public static LineIterator lineIterator(InputStream input, String charsetName) throws IOException
      Returns an Iterator for the lines in an InputStream, using the character encoding specified (or default encoding if null).

      LineIterator holds a reference to the open InputStream specified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by closing the stream directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator).

      The recommended usage pattern is: 

       try {
   LineIterator it = IOUtils.lineIterator(stream, "UTF-8");
   while (it.hasNext()) {
     String line = it.nextLine();
     /// do something with line
   }
 } finally {
   IOUtils.closeQuietly(stream);
 }
      Parameters:
      input - the InputStream to read from, not null
      charsetName - the encoding to use, null means platform default
      Returns:
      an Iterator of the lines in the reader, never null
      Throws:
      IllegalArgumentException - if the input is null
      IOException - if an I/O error occurs, such as if the encoding is invalid
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.2

    • lineIterator

      public static LineIterator lineIterator(Reader reader)
      Returns an Iterator for the lines in a Reader.

      LineIterator holds a reference to the open Reader specified here. When you have finished with the iterator you should close the reader to free internal resources. This can be done by closing the reader directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator).

      The recommended usage pattern is: 

       try {
   LineIterator it = IOUtils.lineIterator(reader);
   while (it.hasNext()) {
     String line = it.nextLine();
     /// do something with line
   }
 } finally {
   IOUtils.closeQuietly(reader);
 }
      Parameters:
      reader - the Reader to read from, not null
      Returns:
      an Iterator of the lines in the reader, never null
      Throws:
      IllegalArgumentException - if the reader is null
      Since:
      1.2

    • read

      public static int read(InputStream input, byte[] buffer) throws IOException
      Reads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of InputStream.
      Parameters:
      input - where to read input from
      buffer - destination
      Returns:
      actual length read; may be less than requested if EOF was reached
      Throws:
      IOException - if a read error occurs
      Since:
      2.2

    • read

      public static int read(InputStream input, byte[] buffer, int offset, int length) throws IOException
      Reads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of InputStream.
      Parameters:
      input - where to read input from
      buffer - destination
      offset - initial offset into buffer
      length - length to read, must be >= 0
      Returns:
      actual length read; may be less than requested if EOF was reached
      Throws:
      IOException - if a read error occurs
      Since:
      2.2

    • read

      public static int read(ReadableByteChannel input, ByteBuffer buffer) throws IOException
      Reads bytes from a ReadableByteChannel.

      This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of ReadableByteChannel.

      Parameters:
      input - the byte channel to read
      buffer - byte buffer destination
      Returns:
      the actual length read; may be less than requested if EOF was reached
      Throws:
      IOException - if a read error occurs
      Since:
      2.5

    • read

      public static int read(Reader input, char[] buffer) throws IOException
      Reads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses of Reader.
      Parameters:
      input - where to read input from
      buffer - destination
      Returns:
      actual length read; may be less than requested if EOF was reached
      Throws:
      IOException - if a read error occurs
      Since:
      2.2

    • read

      public static int read(Reader input, char[] buffer, int offset, int length) throws IOException
      Reads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses of Reader.
      Parameters:
      input - where to read input from
      buffer - destination
      offset - initial offset into buffer
      length - length to read, must be >= 0
      Returns:
      actual length read; may be less than requested if EOF was reached
      Throws:
      IOException - if a read error occurs
      Since:
      2.2

    • readFully

      public static void readFully(InputStream input, byte[] buffer) throws IOException
      Reads the requested number of bytes or fail if there are not enough left.

      This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF).

      Parameters:
      input - where to read input from
      buffer - destination
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if length is negative
      EOFException - if the number of bytes read was incorrect
      Since:
      2.2

    • readFully

      public static void readFully(InputStream input, byte[] buffer, int offset, int length) throws IOException
      Reads the requested number of bytes or fail if there are not enough left.

      This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF).

      Parameters:
      input - where to read input from
      buffer - destination
      offset - initial offset into buffer
      length - length to read, must be >= 0
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if length is negative
      EOFException - if the number of bytes read was incorrect
      Since:
      2.2

    • readFully

      public static byte[] readFully(InputStream input, int length) throws IOException
      Reads the requested number of bytes or fail if there are not enough left.

      This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF).

      Parameters:
      input - where to read input from
      length - length to read, must be >= 0
      Returns:
      the bytes read from input
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if length is negative
      EOFException - if the number of bytes read was incorrect
      Since:
      2.5

    • readFully

      public static void readFully(ReadableByteChannel input, ByteBuffer buffer) throws IOException
      Reads the requested number of bytes or fail if there are not enough left.

      This allows for the possibility that ReadableByteChannel.read(ByteBuffer) may not read as many bytes as requested (most likely because of reaching EOF).

      Parameters:
      input - the byte channel to read
      buffer - byte buffer destination
      Throws:
      IOException - if there is a problem reading the file
      EOFException - if the number of bytes read was incorrect
      Since:
      2.5

    • readFully

      public static void readFully(Reader input, char[] buffer) throws IOException
      Reads the requested number of characters or fail if there are not enough left.

      This allows for the possibility that Reader.read(char[], int, int) may not read as many characters as requested (most likely because of reaching EOF).

      Parameters:
      input - where to read input from
      buffer - destination
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if length is negative
      EOFException - if the number of characters read was incorrect
      Since:
      2.2

    • readFully

      public static void readFully(Reader input, char[] buffer, int offset, int length) throws IOException
      Reads the requested number of characters or fail if there are not enough left.

      This allows for the possibility that Reader.read(char[], int, int) may not read as many characters as requested (most likely because of reaching EOF).

      Parameters:
      input - where to read input from
      buffer - destination
      offset - initial offset into buffer
      length - length to read, must be >= 0
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if length is negative
      EOFException - if the number of characters read was incorrect
      Since:
      2.2

    • readLines

      @Deprecated public static List<String> readLines(InputStream input) throws IOException
      Deprecated.
      2.5 use readLines(InputStream, Charset) instead
      Gets the contents of an InputStream as a list of Strings, one entry per line, using the default character encoding of the platform.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from, not null
      Returns:
      the list of Strings, never null
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • readLines

      public static List<String> readLines(InputStream input, Charset charset) throws IOException
      Gets the contents of an InputStream as a list of Strings, one entry per line, using the specified character encoding.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from, not null
      charset - the charset to use, null means platform default
      Returns:
      the list of Strings, never null
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • readLines

      public static List<String> readLines(InputStream input, String charsetName) throws IOException
      Gets the contents of an InputStream as a list of Strings, one entry per line, using the specified character encoding.

      Character encoding names can be found at IANA.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from, not null
      charsetName - the name of the requested charset, null means platform default
      Returns:
      the list of Strings, never null
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • readLines

      public static List<String> readLines(Reader input) throws IOException
      Gets the contents of a Reader as a list of Strings, one entry per line.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from, not null
      Returns:
      the list of Strings, never null
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • resourceToByteArray

      public static byte[] resourceToByteArray(String name) throws IOException
      Gets the contents of a classpath resource as a byte array.

      It is expected the given name to be absolute. The behavior is not well-defined otherwise.

      Parameters:
      name - name of the desired resource
      Returns:
      the requested byte array
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.6

    • resourceToByteArray

      public static byte[] resourceToByteArray(String name, ClassLoader classLoader) throws IOException
      Gets the contents of a classpath resource as a byte array.

      It is expected the given name to be absolute. The behavior is not well-defined otherwise.

      Parameters:
      name - name of the desired resource
      classLoader - the class loader that the resolution of the resource is delegated to
      Returns:
      the requested byte array
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.6

    • resourceToString

      public static String resourceToString(String name, Charset charset) throws IOException
      Gets the contents of a classpath resource as a String using the specified character encoding.

      It is expected the given name to be absolute. The behavior is not well-defined otherwise.

      Parameters:
      name - name of the desired resource
      charset - the charset to use, null means platform default
      Returns:
      the requested String
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.6

    • resourceToString

      public static String resourceToString(String name, Charset charset, ClassLoader classLoader) throws IOException
      Gets the contents of a classpath resource as a String using the specified character encoding.

      It is expected the given name to be absolute. The behavior is not well-defined otherwise.

      Parameters:
      name - name of the desired resource
      charset - the charset to use, null means platform default
      classLoader - the class loader that the resolution of the resource is delegated to
      Returns:
      the requested String
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.6

    • resourceToURL

      public static URL resourceToURL(String name) throws IOException
      Gets a URL pointing to the given classpath resource.

      It is expected the given name to be absolute. The behavior is not well-defined otherwise.

      Parameters:
      name - name of the desired resource
      Returns:
      the requested URL
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.6

    • resourceToURL

      public static URL resourceToURL(String name, ClassLoader classLoader) throws IOException
      Gets a URL pointing to the given classpath resource.

      It is expected the given name to be absolute. The behavior is not well-defined otherwise.

      Parameters:
      name - name of the desired resource
      classLoader - the class loader that the resolution of the resource is delegated to
      Returns:
      the requested URL
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.6

    • skip

      public static long skip(InputStream input, long toSkip) throws IOException
      Skips bytes from an input byte stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for skip() implementations in subclasses of InputStream.

      Note that the implementation uses InputStream.read(byte[], int, int) rather than delegating to InputStream.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of bytes are skipped.

      Parameters:
      input - byte stream to skip
      toSkip - number of bytes to skip.
      Returns:
      number of bytes actually skipped.
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if toSkip is negative
      Since:
      2.0
      See Also:

    • skip

      public static long skip(ReadableByteChannel input, long toSkip) throws IOException
      Skips bytes from a ReadableByteChannel. This implementation guarantees that it will read as many bytes as possible before giving up.
      Parameters:
      input - ReadableByteChannel to skip
      toSkip - number of bytes to skip.
      Returns:
      number of bytes actually skipped.
      Throws:
      IOException - if there is a problem reading the ReadableByteChannel
      IllegalArgumentException - if toSkip is negative
      Since:
      2.5

    • skip

      public static long skip(Reader input, long toSkip) throws IOException
      Skips characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for skip() implementations in subclasses of Reader.

      Note that the implementation uses Reader.read(char[], int, int) rather than delegating to Reader.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

      Parameters:
      input - character stream to skip
      toSkip - number of characters to skip.
      Returns:
      number of characters actually skipped.
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if toSkip is negative
      Since:
      2.0
      See Also:

    • skipFully

      public static void skipFully(InputStream input, long toSkip) throws IOException
      Skips the requested number of bytes or fail if there are not enough left.

      This allows for the possibility that InputStream.skip(long) may not skip as many bytes as requested (most likely because of reaching EOF).

      Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

      Parameters:
      input - stream to skip
      toSkip - the number of bytes to skip
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if toSkip is negative
      EOFException - if the number of bytes skipped was incorrect
      Since:
      2.0
      See Also:

    • skipFully

      public static void skipFully(ReadableByteChannel input, long toSkip) throws IOException
      Skips the requested number of bytes or fail if there are not enough left.
      Parameters:
      input - ReadableByteChannel to skip
      toSkip - the number of bytes to skip
      Throws:
      IOException - if there is a problem reading the ReadableByteChannel
      IllegalArgumentException - if toSkip is negative
      EOFException - if the number of bytes skipped was incorrect
      Since:
      2.5

    • skipFully

      public static void skipFully(Reader input, long toSkip) throws IOException
      Skips the requested number of characters or fail if there are not enough left.

      This allows for the possibility that Reader.skip(long) may not skip as many characters as requested (most likely because of reaching EOF).

      Note that the implementation uses skip(Reader, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

      Parameters:
      input - stream to skip
      toSkip - the number of characters to skip
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if toSkip is negative
      EOFException - if the number of characters skipped was incorrect
      Since:
      2.0
      See Also:

    • toBufferedInputStream

      public static InputStream toBufferedInputStream(InputStream input) throws IOException
      Fetches entire contents of an InputStream and represent same data as result InputStream.

      This method is useful where,

      • Source InputStream is slow.
      • It has network resources associated, so we cannot keep it open for long time.
      • It has network timeout associated.
      It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].
      This method buffers the input internally, so there is no need to use a BufferedInputStream.
      Parameters:
      input - Stream to be fully buffered.
      Returns:
      A fully buffered stream.
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.0

    • toBufferedInputStream

      public static InputStream toBufferedInputStream(InputStream input, int size) throws IOException
      Fetches entire contents of an InputStream and represent same data as result InputStream.

      This method is useful where,

      • Source InputStream is slow.
      • It has network resources associated, so we cannot keep it open for long time.
      • It has network timeout associated.
      It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].
      This method buffers the input internally, so there is no need to use a BufferedInputStream.
      Parameters:
      input - Stream to be fully buffered.
      size - the initial buffer size
      Returns:
      A fully buffered stream.
      Throws:
      IOException - if an I/O error occurs
      Since:
      2.5

    • toBufferedReader

      public static BufferedReader toBufferedReader(Reader reader)
      Returns the given reader if it is a BufferedReader, otherwise creates a BufferedReader from the given reader.
      Parameters:
      reader - the reader to wrap or return (not null)
      Returns:
      the given reader or a new BufferedReader for the given reader
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.2
      See Also:

    • toBufferedReader

      public static BufferedReader toBufferedReader(Reader reader, int size)
      Returns the given reader if it is a BufferedReader, otherwise creates a BufferedReader from the given reader.
      Parameters:
      reader - the reader to wrap or return (not null)
      size - the buffer size, if a new BufferedReader is created.
      Returns:
      the given reader or a new BufferedReader for the given reader
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.5
      See Also:

    • toByteArray

      public static byte[] toByteArray(InputStream input) throws IOException
      Gets the contents of an InputStream as a byte[].

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs

    • toByteArray

      public static byte[] toByteArray(InputStream input, int size) throws IOException
      Gets the contents of an InputStream as a byte[]. Use this method instead of toByteArray(InputStream) when InputStream size is known
      Parameters:
      input - the InputStream to read from
      size - the size of InputStream
      Returns:
      the requested byte array
      Throws:
      IOException - if an I/O error occurs or InputStream size differ from parameter size
      IllegalArgumentException - if size is less than zero
      Since:
      2.1

    • toByteArray

      public static byte[] toByteArray(InputStream input, long size) throws IOException
      Gets contents of an InputStream as a byte[]. Use this method instead of toByteArray(InputStream) when InputStream size is known. NOTE: the method checks that the length can safely be cast to an int without truncation before using toByteArray(java.io.InputStream, int) to read into the byte array. (Arrays can have no more than Integer.MAX_VALUE entries anyway)
      Parameters:
      input - the InputStream to read from
      size - the size of InputStream
      Returns:
      the requested byte array
      Throws:
      IOException - if an I/O error occurs or InputStream size differ from parameter size
      IllegalArgumentException - if size is less than zero or size is greater than Integer.MAX_VALUE
      Since:
      2.1
      See Also:

    • toByteArray

      @Deprecated public static byte[] toByteArray(Reader input) throws IOException
      Deprecated.
      2.5 use toByteArray(Reader, Charset) instead
      Gets the contents of a Reader as a byte[] using the default character encoding of the platform.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs

    • toByteArray

      public static byte[] toByteArray(Reader input, Charset charset) throws IOException
      Gets the contents of a Reader as a byte[] using the specified character encoding.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      charset - the charset to use, null means platform default
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • toByteArray

      public static byte[] toByteArray(Reader input, String charsetName) throws IOException
      Gets the contents of a Reader as a byte[] using the specified character encoding.

      Character encoding names can be found at IANA.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      charsetName - the name of the requested charset, null means platform default
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • toByteArray

      @Deprecated public static byte[] toByteArray(String input) throws IOException
      Deprecated.
      2.5 Use String.getBytes() instead
      Gets the contents of a String as a byte[] using the default character encoding of the platform.

      This is the same as String.getBytes().

      Parameters:
      input - the String to convert
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs (never occurs)

    • toByteArray

      public static byte[] toByteArray(URI uri) throws IOException
      Gets the contents of a URI as a byte[].
      Parameters:
      uri - the URI to read
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the uri is null
      IOException - if an I/O exception occurs
      Since:
      2.4

    • toByteArray

      public static byte[] toByteArray(URL url) throws IOException
      Gets the contents of a URL as a byte[].
      Parameters:
      url - the URL to read
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O exception occurs
      Since:
      2.4

    • toByteArray

      public static byte[] toByteArray(URLConnection urlConn) throws IOException
      Gets the contents of a URLConnection as a byte[].
      Parameters:
      urlConn - the URLConnection to read
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the urlConn is null
      IOException - if an I/O exception occurs
      Since:
      2.4

    • toCharArray

      @Deprecated public static char[] toCharArray(InputStream is) throws IOException
      Deprecated.
      2.5 use toCharArray(InputStream, Charset) instead
      Gets the contents of an InputStream as a character array using the default character encoding of the platform.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      is - the InputStream to read from
      Returns:
      the requested character array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • toCharArray

      public static char[] toCharArray(InputStream is, Charset charset) throws IOException
      Gets the contents of an InputStream as a character array using the specified character encoding.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      is - the InputStream to read from
      charset - the charset to use, null means platform default
      Returns:
      the requested character array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • toCharArray

      public static char[] toCharArray(InputStream is, String charsetName) throws IOException
      Gets the contents of an InputStream as a character array using the specified character encoding.

      Character encoding names can be found at IANA.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      is - the InputStream to read from
      charsetName - the name of the requested charset, null means platform default
      Returns:
      the requested character array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • toCharArray

      public static char[] toCharArray(Reader input) throws IOException
      Gets the contents of a Reader as a character array.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      Returns:
      the requested character array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • toInputStream

      @Deprecated public static InputStream toInputStream(CharSequence input)
      Deprecated.
      2.5 use toInputStream(CharSequence, Charset) instead
      Converts the specified CharSequence to an input stream, encoded as bytes using the default character encoding of the platform.
      Parameters:
      input - the CharSequence to convert
      Returns:
      an input stream
      Since:
      2.0

    • toInputStream

      public static InputStream toInputStream(CharSequence input, Charset charset)
      Converts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.
      Parameters:
      input - the CharSequence to convert
      charset - the charset to use, null means platform default
      Returns:
      an input stream
      Since:
      2.3

    • toInputStream

      public static InputStream toInputStream(CharSequence input, String charsetName) throws IOException
      Converts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.

      Character encoding names can be found at IANA.

      Parameters:
      input - the CharSequence to convert
      charsetName - the name of the requested charset, null means platform default
      Returns:
      an input stream
      Throws:
      IOException - if the encoding is invalid
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      2.0

    • toInputStream

      @Deprecated public static InputStream toInputStream(String input)
      Deprecated.
      2.5 use toInputStream(String, Charset) instead
      Converts the specified string to an input stream, encoded as bytes using the default character encoding of the platform.
      Parameters:
      input - the string to convert
      Returns:
      an input stream
      Since:
      1.1

    • toInputStream

      public static InputStream toInputStream(String input, Charset charset)
      Converts the specified string to an input stream, encoded as bytes using the specified character encoding.
      Parameters:
      input - the string to convert
      charset - the charset to use, null means platform default
      Returns:
      an input stream
      Since:
      2.3

    • toInputStream

      public static InputStream toInputStream(String input, String charsetName) throws IOException
      Converts the specified string to an input stream, encoded as bytes using the specified character encoding.

      Character encoding names can be found at IANA.

      Parameters:
      input - the string to convert
      charsetName - the name of the requested charset, null means platform default
      Returns:
      an input stream
      Throws:
      IOException - if the encoding is invalid
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • toString

      @Deprecated public static String toString(byte[] input) throws IOException
      Deprecated.
      2.5 Use String(byte[]) instead
      Gets the contents of a byte[] as a String using the default character encoding of the platform.
      Parameters:
      input - the byte array to read from
      Returns:
      the requested String
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs (never occurs)

    • toString

      public static String toString(byte[] input, String charsetName) throws IOException
      Gets the contents of a byte[] as a String using the specified character encoding.

      Character encoding names can be found at IANA.

      Parameters:
      input - the byte array to read from
      charsetName - the name of the requested charset, null means platform default
      Returns:
      the requested String
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs (never occurs)

    • toString

      @Deprecated public static String toString(InputStream input) throws IOException
      Deprecated.
      2.5 use toString(InputStream, Charset) instead
      Gets the contents of an InputStream as a String using the default character encoding of the platform.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from
      Returns:
      the requested String
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs

    • toString

      public static String toString(InputStream input, Charset charset) throws IOException
      Gets the contents of an InputStream as a String using the specified character encoding.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from
      charset - the charset to use, null means platform default
      Returns:
      the requested String
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • toString

      public static String toString(InputStream input, String charsetName) throws IOException
      Gets the contents of an InputStream as a String using the specified character encoding.

      Character encoding names can be found at IANA.

      This method buffers the input internally, so there is no need to use a BufferedInputStream.

      Parameters:
      input - the InputStream to read from
      charsetName - the name of the requested charset, null means platform default
      Returns:
      the requested String
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.

    • toString

      public static String toString(Reader input) throws IOException
      Gets the contents of a Reader as a String.

      This method buffers the input internally, so there is no need to use a BufferedReader.

      Parameters:
      input - the Reader to read from
      Returns:
      the requested String
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs

    • toString

      @Deprecated public static String toString(URI uri) throws IOException
      Deprecated.
      2.5 use toString(URI, Charset) instead
      Gets the contents at the given URI.
      Parameters:
      uri - The URI source.
      Returns:
      The contents of the URL as a String.
      Throws:
      IOException - if an I/O exception occurs.
      Since:
      2.1

    • toString

      public static String toString(URI uri, Charset encoding) throws IOException
      Gets the contents at the given URI.
      Parameters:
      uri - The URI source.
      encoding - The encoding name for the URL contents.
      Returns:
      The contents of the URL as a String.
      Throws:
      IOException - if an I/O exception occurs.
      Since:
      2.3.

    • toString

      public static String toString(URI uri, String charsetName) throws IOException
      Gets the contents at the given URI.
      Parameters:
      uri - The URI source.
      charsetName - The encoding name for the URL contents.
      Returns:
      The contents of the URL as a String.
      Throws:
      IOException - if an I/O exception occurs.
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      2.1

    • toString

      @Deprecated public static String toString(URL url) throws IOException
      Deprecated.
      2.5 use toString(URL, Charset) instead
      Gets the contents at the given URL.
      Parameters:
      url - The URL source.
      Returns:
      The contents of the URL as a String.
      Throws:
      IOException - if an I/O exception occurs.
      Since:
      2.1

    • toString

      public static String toString(URL url, Charset encoding) throws IOException
      Gets the contents at the given URL.
      Parameters:
      url - The URL source.
      encoding - The encoding name for the URL contents.
      Returns:
      The contents of the URL as a String.
      Throws:
      IOException - if an I/O exception occurs.
      Since:
      2.3

    • toString

      public static String toString(URL url, String charsetName) throws IOException
      Gets the contents at the given URL.
      Parameters:
      url - The URL source.
      charsetName - The encoding name for the URL contents.
      Returns:
      The contents of the URL as a String.
      Throws:
      IOException - if an I/O exception occurs.
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      2.1

    • write

      public static void write(byte[] data, OutputStream output) throws IOException
      Writes bytes from a byte[] to an OutputStream.
      Parameters:
      data - the byte array to write, do not modify during output, null ignored
      output - the OutputStream to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • write

      @Deprecated public static void write(byte[] data, Writer output) throws IOException
      Deprecated.
      2.5 use write(byte[], Writer, Charset) instead
      Writes bytes from a byte[] to chars on a Writer using the default character encoding of the platform.

      This method uses String(byte[]).

      Parameters:
      data - the byte array to write, do not modify during output, null ignored
      output - the Writer to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • write

      public static void write(byte[] data, Writer output, Charset charset) throws IOException
      Writes bytes from a byte[] to chars on a Writer using the specified character encoding.

      This method uses String(byte[], String).

      Parameters:
      data - the byte array to write, do not modify during output, null ignored
      output - the Writer to write to
      charset - the charset to use, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • write

      public static void write(byte[] data, Writer output, String charsetName) throws IOException
      Writes bytes from a byte[] to chars on a Writer using the specified character encoding.

      Character encoding names can be found at IANA.

      This method uses String(byte[], String).

      Parameters:
      data - the byte array to write, do not modify during output, null ignored
      output - the Writer to write to
      charsetName - the name of the requested charset, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • write

      @Deprecated public static void write(char[] data, OutputStream output) throws IOException
      Deprecated.
      2.5 use write(char[], OutputStream, Charset) instead
      Writes chars from a char[] to bytes on an OutputStream.

      This method uses String(char[]) and String.getBytes().

      Parameters:
      data - the char array to write, do not modify during output, null ignored
      output - the OutputStream to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • write

      public static void write(char[] data, OutputStream output, Charset charset) throws IOException
      Writes chars from a char[] to bytes on an OutputStream using the specified character encoding.

      This method uses String(char[]) and String.getBytes(String).

      Parameters:
      data - the char array to write, do not modify during output, null ignored
      output - the OutputStream to write to
      charset - the charset to use, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • write

      public static void write(char[] data, OutputStream output, String charsetName) throws IOException
      Writes chars from a char[] to bytes on an OutputStream using the specified character encoding.

      Character encoding names can be found at IANA.

      This method uses String(char[]) and String.getBytes(String).

      Parameters:
      data - the char array to write, do not modify during output, null ignored
      output - the OutputStream to write to
      charsetName - the name of the requested charset, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • write

      public static void write(char[] data, Writer output) throws IOException
      Writes chars from a char[] to a Writer
      Parameters:
      data - the char array to write, do not modify during output, null ignored
      output - the Writer to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • write

      @Deprecated public static void write(CharSequence data, OutputStream output) throws IOException
      Deprecated.
      2.5 use write(CharSequence, OutputStream, Charset) instead
      Writes chars from a CharSequence to bytes on an OutputStream using the default character encoding of the platform.

      This method uses String.getBytes().

      Parameters:
      data - the CharSequence to write, null ignored
      output - the OutputStream to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.0

    • write

      public static void write(CharSequence data, OutputStream output, Charset charset) throws IOException
      Writes chars from a CharSequence to bytes on an OutputStream using the specified character encoding.

      This method uses String.getBytes(String).

      Parameters:
      data - the CharSequence to write, null ignored
      output - the OutputStream to write to
      charset - the charset to use, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • write

      public static void write(CharSequence data, OutputStream output, String charsetName) throws IOException
      Writes chars from a CharSequence to bytes on an OutputStream using the specified character encoding.

      Character encoding names can be found at IANA.

      This method uses String.getBytes(String).

      Parameters:
      data - the CharSequence to write, null ignored
      output - the OutputStream to write to
      charsetName - the name of the requested charset, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      2.0

    • write

      public static void write(CharSequence data, Writer output) throws IOException
      Writes chars from a CharSequence to a Writer.
      Parameters:
      data - the CharSequence to write, null ignored
      output - the Writer to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.0

    • write

      @Deprecated public static void write(String data, OutputStream output) throws IOException
      Deprecated.
      2.5 use write(String, OutputStream, Charset) instead
      Writes chars from a String to bytes on an OutputStream using the default character encoding of the platform.

      This method uses String.getBytes().

      Parameters:
      data - the String to write, null ignored
      output - the OutputStream to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • write

      public static void write(String data, OutputStream output, Charset charset) throws IOException
      Writes chars from a String to bytes on an OutputStream using the specified character encoding.

      This method uses String.getBytes(String).

      Parameters:
      data - the String to write, null ignored
      output - the OutputStream to write to
      charset - the charset to use, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • write

      public static void write(String data, OutputStream output, String charsetName) throws IOException
      Writes chars from a String to bytes on an OutputStream using the specified character encoding.

      Character encoding names can be found at IANA.

      This method uses String.getBytes(String).

      Parameters:
      data - the String to write, null ignored
      output - the OutputStream to write to
      charsetName - the name of the requested charset, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • write

      public static void write(String data, Writer output) throws IOException
      Writes chars from a String to a Writer.
      Parameters:
      data - the String to write, null ignored
      output - the Writer to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • write

      @Deprecated public static void write(StringBuffer data, OutputStream output) throws IOException
      Deprecated.
      replaced by write(CharSequence, OutputStream)
      Writes chars from a StringBuffer to bytes on an OutputStream using the default character encoding of the platform.

      This method uses String.getBytes().

      Parameters:
      data - the StringBuffer to write, null ignored
      output - the OutputStream to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • write

      @Deprecated public static void write(StringBuffer data, OutputStream output, String charsetName) throws IOException
      Deprecated.
      replaced by write(CharSequence, OutputStream, String)
      Writes chars from a StringBuffer to bytes on an OutputStream using the specified character encoding.

      Character encoding names can be found at IANA.

      This method uses String.getBytes(String).

      Parameters:
      data - the StringBuffer to write, null ignored
      output - the OutputStream to write to
      charsetName - the name of the requested charset, null means platform default
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • write

      @Deprecated public static void write(StringBuffer data, Writer output) throws IOException
      Deprecated.
      replaced by write(CharSequence, Writer)
      Writes chars from a StringBuffer to a Writer.
      Parameters:
      data - the StringBuffer to write, null ignored
      output - the Writer to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • writeChunked

      public static void writeChunked(byte[] data, OutputStream output) throws IOException
      Writes bytes from a byte[] to an OutputStream using chunked writes. This is intended for writing very large byte arrays which might otherwise cause excessive memory usage if the native code has to allocate a copy.
      Parameters:
      data - the byte array to write, do not modify during output, null ignored
      output - the OutputStream to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.5

    • writeChunked

      public static void writeChunked(char[] data, Writer output) throws IOException
      Writes chars from a char[] to a Writer using chunked writes. This is intended for writing very large byte arrays which might otherwise cause excessive memory usage if the native code has to allocate a copy.
      Parameters:
      data - the char array to write, do not modify during output, null ignored
      output - the Writer to write to
      Throws:
      NullPointerException - if output is null
      IOException - if an I/O error occurs
      Since:
      2.5

    • writeLines

      @Deprecated public static void writeLines(Collection<?> lines, String lineEnding, OutputStream output) throws IOException
      Deprecated.
      2.5 use writeLines(Collection, String, OutputStream, Charset) instead
      Writes the toString() value of each item in a collection to an OutputStream line by line, using the default character encoding of the platform and the specified line ending.
      Parameters:
      lines - the lines to write, null entries produce blank lines
      lineEnding - the line separator to use, null is system default
      output - the OutputStream to write to, not null, not closed
      Throws:
      NullPointerException - if the output is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • writeLines

      public static void writeLines(Collection<?> lines, String lineEnding, OutputStream output, Charset charset) throws IOException
      Writes the toString() value of each item in a collection to an OutputStream line by line, using the specified character encoding and the specified line ending.
      Parameters:
      lines - the lines to write, null entries produce blank lines
      lineEnding - the line separator to use, null is system default
      output - the OutputStream to write to, not null, not closed
      charset - the charset to use, null means platform default
      Throws:
      NullPointerException - if the output is null
      IOException - if an I/O error occurs
      Since:
      2.3

    • writeLines

      public static void writeLines(Collection<?> lines, String lineEnding, OutputStream output, String charsetName) throws IOException
      Writes the toString() value of each item in a collection to an OutputStream line by line, using the specified character encoding and the specified line ending.

      Character encoding names can be found at IANA.

      Parameters:
      lines - the lines to write, null entries produce blank lines
      lineEnding - the line separator to use, null is system default
      output - the OutputStream to write to, not null, not closed
      charsetName - the name of the requested charset, null means platform default
      Throws:
      NullPointerException - if the output is null
      IOException - if an I/O error occurs
      UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      Since:
      1.1

    • writeLines

      public static void writeLines(Collection<?> lines, String lineEnding, Writer writer) throws IOException
      Writes the toString() value of each item in a collection to a Writer line by line, using the specified line ending.
      Parameters:
      lines - the lines to write, null entries produce blank lines
      lineEnding - the line separator to use, null is system default
      writer - the Writer to write to, not null, not closed
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs
      Since:
      1.1

    • writer

      public static Writer writer(Appendable appendable)
      Returns the given Appendable if it is already a Writer, otherwise creates a Writer wrapper around the given Appendable.
      Parameters:
      appendable - the Appendable to wrap or return (not null)
      Returns:
      the given Appendable or a Writer wrapper around the given Appendable
      Throws:
      NullPointerException - if the input parameter is null
      Since:
      2.7