Package org.apache.commons.codec.net

Class QuotedPrintableCodec

  • All Implemented Interfaces:
    BinaryDecoder, BinaryEncoder, Decoder, Encoder, StringDecoder, StringEncoder
    public class QuotedPrintableCodec
extends java.lang.Object
implements BinaryEncoder, BinaryDecoder, StringEncoder, StringDecoder
    Codec for the Quoted-Printable section of RFC 1521.

    The Quoted-Printable encoding is intended to represent data that largely consists of octets that correspond to printable characters in the ASCII character set. It encodes the data in such a way that the resulting octets are unlikely to be modified by mail transport. If the data being encoded are mostly ASCII text, the encoded form of the data remains largely recognizable by humans. A body which is entirely ASCII may also be encoded in Quoted-Printable to ensure the integrity of the data should the message pass through a character- translating, and/or line-wrapping gateway.

    Note:

    Depending on the selected strict parameter, this class will implement a different set of rules of the quoted-printable spec:

    • strict=false: only rules #1 and #2 are implemented
    • strict=true: all rules #1 through #5 are implemented
    Originally, this class only supported the non-strict mode, but the codec in this partial form could already be used for certain applications that do not require quoted-printable line formatting (rules #3, #4, #5), for instance Q codec. The strict mode has been added in 1.10.

    This class is immutable and thread-safe.

    Since:
    1.3
    See Also:
    RFC 1521 MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.nio.charset.Charset charset
      The default Charset used for string decoding and encoding.
      private static byte CR  
      private static byte ESCAPE_CHAR  
      private static byte LF  
      private static java.util.BitSet PRINTABLE_CHARS
      BitSet of printable characters as defined in RFC 1521.
      private static int SAFE_LENGTH
      Safe line length for quoted printable encoded text.
      private static byte SPACE  
      private boolean strict
      Indicates whether soft line breaks shall be used during encoding (rule #3-5).
      private static byte TAB  

    • Constructor Summary

      Constructors 
      Constructor Description
      QuotedPrintableCodec()
      Default constructor, assumes default Charset of Charsets.UTF_8
      QuotedPrintableCodec​(boolean strict)
      Constructor which allows for the selection of the strict mode.
      QuotedPrintableCodec​(java.lang.String charsetName)
      Constructor which allows for the selection of a default Charset.
      QuotedPrintableCodec​(java.nio.charset.Charset charset)
      Constructor which allows for the selection of a default Charset.
      QuotedPrintableCodec​(java.nio.charset.Charset charset, boolean strict)
      Constructor which allows for the selection of a default Charset and strict mode.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      byte[] decode​(byte[] bytes)
      Decodes an array of quoted-printable characters into an array of original bytes.
      java.lang.Object decode​(java.lang.Object obj)
      Decodes a quoted-printable object into its original form.
      java.lang.String decode​(java.lang.String sourceStr)
      Decodes a quoted-printable string into its original form using the default string Charset.
      java.lang.String decode​(java.lang.String sourceStr, java.lang.String sourceCharset)
      Decodes a quoted-printable string into its original form using the specified string Charset.
      java.lang.String decode​(java.lang.String sourceStr, java.nio.charset.Charset sourceCharset)
      Decodes a quoted-printable string into its original form using the specified string Charset.
      static byte[] decodeQuotedPrintable​(byte[] bytes)
      Decodes an array quoted-printable characters into an array of original bytes.
      byte[] encode​(byte[] bytes)
      Encodes an array of bytes into an array of quoted-printable 7-bit characters.
      java.lang.Object encode​(java.lang.Object obj)
      Encodes an object into its quoted-printable safe form.
      java.lang.String encode​(java.lang.String sourceStr)
      Encodes a string into its quoted-printable form using the default string Charset.
      java.lang.String encode​(java.lang.String sourceStr, java.lang.String sourceCharset)
      Encodes a string into its quoted-printable form using the specified Charset.
      java.lang.String encode​(java.lang.String sourceStr, java.nio.charset.Charset sourceCharset)
      Encodes a string into its quoted-printable form using the specified Charset.
      private static int encodeByte​(int b, boolean encode, java.io.ByteArrayOutputStream buffer)
      Write a byte to the buffer.
      private static int encodeQuotedPrintable​(int b, java.io.ByteArrayOutputStream buffer)
      Encodes byte into its quoted-printable representation.
      static byte[] encodeQuotedPrintable​(java.util.BitSet printable, byte[] bytes)
      Encodes an array of bytes into an array of quoted-printable 7-bit characters.
      static byte[] encodeQuotedPrintable​(java.util.BitSet printable, byte[] bytes, boolean strict)
      Encodes an array of bytes into an array of quoted-printable 7-bit characters.
      java.nio.charset.Charset getCharset()
      Gets the default Charset name used for string decoding and encoding.
      java.lang.String getDefaultCharset()
      Gets the default Charset name used for string decoding and encoding.
      private static int getUnsignedOctet​(int index, byte[] bytes)
      Return the byte at position index of the byte array and make sure it is unsigned.
      private static boolean isWhitespace​(int b)
      Checks whether the given byte is whitespace.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • charset

        private final java.nio.charset.Charset charset
        The default Charset used for string decoding and encoding.

      • strict

        private final boolean strict
        Indicates whether soft line breaks shall be used during encoding (rule #3-5).

      • PRINTABLE_CHARS

        private static final java.util.BitSet PRINTABLE_CHARS
        BitSet of printable characters as defined in RFC 1521.

      • SAFE_LENGTH

        private static final int SAFE_LENGTH
        Safe line length for quoted printable encoded text.
        See Also:
        Constant Field Values

    • Constructor Detail

      • QuotedPrintableCodec

        public QuotedPrintableCodec()
        Default constructor, assumes default Charset of Charsets.UTF_8

      • QuotedPrintableCodec

        public QuotedPrintableCodec​(boolean strict)
        Constructor which allows for the selection of the strict mode.
        Parameters:
        strict - if true, soft line breaks will be used
        Since:
        1.10

      • QuotedPrintableCodec

        public QuotedPrintableCodec​(java.nio.charset.Charset charset)
        Constructor which allows for the selection of a default Charset.
        Parameters:
        charset - the default string Charset to use.
        Since:
        1.7

      • QuotedPrintableCodec

        public QuotedPrintableCodec​(java.nio.charset.Charset charset,
                            boolean strict)
        Constructor which allows for the selection of a default Charset and strict mode.
        Parameters:
        charset - the default string Charset to use.
        strict - if true, soft line breaks will be used
        Since:
        1.10

      • QuotedPrintableCodec

        public QuotedPrintableCodec​(java.lang.String charsetName)
                     throws java.nio.charset.IllegalCharsetNameException,
                            java.lang.IllegalArgumentException,
                            java.nio.charset.UnsupportedCharsetException
        Constructor which allows for the selection of a default Charset.
        Parameters:
        charsetName - the default string Charset to use.
        Throws:
        java.nio.charset.UnsupportedCharsetException - If no support for the named Charset is available in this instance of the Java virtual machine
        java.lang.IllegalArgumentException - If the given charsetName is null
        java.nio.charset.IllegalCharsetNameException - If the given Charset name is illegal
        Since:
        1.7 throws UnsupportedCharsetException if the named Charset is unavailable

    • Method Detail

      • encodeQuotedPrintable

        private static final int encodeQuotedPrintable​(int b,
                                               java.io.ByteArrayOutputStream buffer)
        Encodes byte into its quoted-printable representation.
        Parameters:
        b - byte to encode
        buffer - the buffer to write to
        Returns:
        The number of bytes written to the buffer

      • getUnsignedOctet

        private static int getUnsignedOctet​(int index,
                                    byte[] bytes)
        Return the byte at position index of the byte array and make sure it is unsigned.
        Parameters:
        index - position in the array
        bytes - the byte array
        Returns:
        the unsigned octet at position index from the array

      • encodeByte

        private static int encodeByte​(int b,
                              boolean encode,
                              java.io.ByteArrayOutputStream buffer)
        Write a byte to the buffer.
        Parameters:
        b - byte to write
        encode - indicates whether the octet shall be encoded
        buffer - the buffer to write to
        Returns:
        the number of bytes that have been written to the buffer

      • isWhitespace

        private static boolean isWhitespace​(int b)
        Checks whether the given byte is whitespace.
        Parameters:
        b - byte to be checked
        Returns:
        true if the byte is either a space or tab character

      • encodeQuotedPrintable

        public static final byte[] encodeQuotedPrintable​(java.util.BitSet printable,
                                                 byte[] bytes)
        Encodes an array of bytes into an array of quoted-printable 7-bit characters. Unsafe characters are escaped.

        This function implements a subset of quoted-printable encoding specification (rule #1 and rule #2) as defined in RFC 1521 and is suitable for encoding binary data and unformatted text.

        Parameters:
        printable - bitset of characters deemed quoted-printable
        bytes - array of bytes to be encoded
        Returns:
        array of bytes containing quoted-printable data

      • encodeQuotedPrintable

        public static final byte[] encodeQuotedPrintable​(java.util.BitSet printable,
                                                 byte[] bytes,
                                                 boolean strict)
        Encodes an array of bytes into an array of quoted-printable 7-bit characters. Unsafe characters are escaped.

        Depending on the selection of the strict parameter, this function either implements the full ruleset or only a subset of quoted-printable encoding specification (rule #1 and rule #2) as defined in RFC 1521 and is suitable for encoding binary data and unformatted text.

        Parameters:
        printable - bitset of characters deemed quoted-printable
        bytes - array of bytes to be encoded
        strict - if true the full ruleset is used, otherwise only rule #1 and rule #2
        Returns:
        array of bytes containing quoted-printable data
        Since:
        1.10

      • decodeQuotedPrintable

        public static final byte[] decodeQuotedPrintable​(byte[] bytes)
                                          throws DecoderException
        Decodes an array quoted-printable characters into an array of original bytes. Escaped characters are converted back to their original representation.

        This function fully implements the quoted-printable encoding specification (rule #1 through rule #5) as defined in RFC 1521.

        Parameters:
        bytes - array of quoted-printable characters
        Returns:
        array of original bytes
        Throws:
        DecoderException - Thrown if quoted-printable decoding is unsuccessful

      • encode

        public byte[] encode​(byte[] bytes)
        Encodes an array of bytes into an array of quoted-printable 7-bit characters. Unsafe characters are escaped.

        Depending on the selection of the strict parameter, this function either implements the full ruleset or only a subset of quoted-printable encoding specification (rule #1 and rule #2) as defined in RFC 1521 and is suitable for encoding binary data and unformatted text.

        Specified by:
        encode in interface BinaryEncoder
        Parameters:
        bytes - array of bytes to be encoded
        Returns:
        array of bytes containing quoted-printable data

      • decode

        public byte[] decode​(byte[] bytes)
              throws DecoderException
        Decodes an array of quoted-printable characters into an array of original bytes. Escaped characters are converted back to their original representation.

        This function fully implements the quoted-printable encoding specification (rule #1 through rule #5) as defined in RFC 1521.

        Specified by:
        decode in interface BinaryDecoder
        Parameters:
        bytes - array of quoted-printable characters
        Returns:
        array of original bytes
        Throws:
        DecoderException - Thrown if quoted-printable decoding is unsuccessful

      • encode

        public java.lang.String encode​(java.lang.String sourceStr)
                        throws EncoderException
        Encodes a string into its quoted-printable form using the default string Charset. Unsafe characters are escaped.

        Depending on the selection of the strict parameter, this function either implements the full ruleset or only a subset of quoted-printable encoding specification (rule #1 and rule #2) as defined in RFC 1521 and is suitable for encoding binary data and unformatted text.

        Specified by:
        encode in interface StringEncoder
        Parameters:
        sourceStr - string to convert to quoted-printable form
        Returns:
        quoted-printable string
        Throws:
        EncoderException - Thrown if quoted-printable encoding is unsuccessful
        See Also:
        getCharset()

      • decode

        public java.lang.String decode​(java.lang.String sourceStr,
                               java.nio.charset.Charset sourceCharset)
                        throws DecoderException
        Decodes a quoted-printable string into its original form using the specified string Charset. Escaped characters are converted back to their original representation.
        Parameters:
        sourceStr - quoted-printable string to convert into its original form
        sourceCharset - the original string Charset
        Returns:
        original string
        Throws:
        DecoderException - Thrown if quoted-printable decoding is unsuccessful
        Since:
        1.7

      • decode

        public java.lang.String decode​(java.lang.String sourceStr,
                               java.lang.String sourceCharset)
                        throws DecoderException,
                               java.io.UnsupportedEncodingException
        Decodes a quoted-printable string into its original form using the specified string Charset. Escaped characters are converted back to their original representation.
        Parameters:
        sourceStr - quoted-printable string to convert into its original form
        sourceCharset - the original string Charset
        Returns:
        original string
        Throws:
        DecoderException - Thrown if quoted-printable decoding is unsuccessful
        java.io.UnsupportedEncodingException - Thrown if Charset is not supported

      • decode

        public java.lang.String decode​(java.lang.String sourceStr)
                        throws DecoderException
        Decodes a quoted-printable string into its original form using the default string Charset. Escaped characters are converted back to their original representation.
        Specified by:
        decode in interface StringDecoder
        Parameters:
        sourceStr - quoted-printable string to convert into its original form
        Returns:
        original string
        Throws:
        DecoderException - Thrown if quoted-printable decoding is unsuccessful. Thrown if Charset is not supported.
        See Also:
        getCharset()

      • encode

        public java.lang.Object encode​(java.lang.Object obj)
                        throws EncoderException
        Encodes an object into its quoted-printable safe form. Unsafe characters are escaped.
        Specified by:
        encode in interface Encoder
        Parameters:
        obj - string to convert to a quoted-printable form
        Returns:
        quoted-printable object
        Throws:
        EncoderException - Thrown if quoted-printable encoding is not applicable to objects of this type or if encoding is unsuccessful

      • decode

        public java.lang.Object decode​(java.lang.Object obj)
                        throws DecoderException
        Decodes a quoted-printable object into its original form. Escaped characters are converted back to their original representation.
        Specified by:
        decode in interface Decoder
        Parameters:
        obj - quoted-printable object to convert into its original form
        Returns:
        original object
        Throws:
        DecoderException - Thrown if the argument is not a String or byte[]. Thrown if a failure condition is encountered during the decode process.

      • getCharset

        public java.nio.charset.Charset getCharset()
        Gets the default Charset name used for string decoding and encoding.
        Returns:
        the default Charset name
        Since:
        1.7

      • getDefaultCharset

        public java.lang.String getDefaultCharset()
        Gets the default Charset name used for string decoding and encoding.
        Returns:
        the default Charset name

      • encode

        public java.lang.String encode​(java.lang.String sourceStr,
                               java.nio.charset.Charset sourceCharset)
        Encodes a string into its quoted-printable form using the specified Charset. Unsafe characters are escaped.

        Depending on the selection of the strict parameter, this function either implements the full ruleset or only a subset of quoted-printable encoding specification (rule #1 and rule #2) as defined in RFC 1521 and is suitable for encoding binary data and unformatted text.

        Parameters:
        sourceStr - string to convert to quoted-printable form
        sourceCharset - the Charset for sourceStr
        Returns:
        quoted-printable string
        Since:
        1.7

      • encode

        public java.lang.String encode​(java.lang.String sourceStr,
                               java.lang.String sourceCharset)
                        throws java.io.UnsupportedEncodingException
        Encodes a string into its quoted-printable form using the specified Charset. Unsafe characters are escaped.

        Depending on the selection of the strict parameter, this function either implements the full ruleset or only a subset of quoted-printable encoding specification (rule #1 and rule #2) as defined in RFC 1521 and is suitable for encoding binary data and unformatted text.

        Parameters:
        sourceStr - string to convert to quoted-printable form
        sourceCharset - the Charset for sourceStr
        Returns:
        quoted-printable string
        Throws:
        java.io.UnsupportedEncodingException - Thrown if the Charset is not supported