Package org.apache.bcel.classfile

Class ClassParser

  • public final class ClassParser
extends java.lang.Object
    Wrapper class that parses a given Java .class file. The method parse returns a JavaClass object on success. When an I/O error or an inconsistency occurs an appropiate exception is propagated back to the caller. The structure and the names comply, except for a few conveniences, exactly with the JVM specification 1.0. See this paper for further details about the structure of a bytecode file.

    • Constructor Summary

      Constructors 
      Constructor Description
      ClassParser​(java.io.InputStream inputStream, java.lang.String file_name)
      Parses class from the given stream.
      ClassParser​(java.lang.String file_name)
      Parses class from given .class file.
      ClassParser​(java.lang.String zip_file, java.lang.String file_name)
      Parses class from given .class file in a ZIP-archive

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      JavaClass parse()
      Parses the given Java class file and return an object that represents the contained data, i.e., constants, methods, fields and commands.
      private void readAttributes()
      Reads information about the attributes of the class.
      private void readClassInfo()
      Reads information about the class and its super class.
      private void readConstantPool()
      Reads constant pool entries.
      private void readFields()
      Reads information about the fields of the class, i.e., its variables.
      private void readID()
      Checks whether the header of the file is ok.
      private void readInterfaces()
      Reads information about the interfaces implemented by this class.
      private void readMethods()
      Reads information about the methods of the class.
      private void readVersion()
      Reads major and minor version of compiler which created the file.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • dataInputStream

        private java.io.DataInputStream dataInputStream

      • fileOwned

        private final boolean fileOwned

      • file_name

        private final java.lang.String file_name

      • zip_file

        private java.lang.String zip_file

      • class_name_index

        private int class_name_index

      • superclass_name_index

        private int superclass_name_index

      • major

        private int major

      • minor

        private int minor

      • access_flags

        private int access_flags

      • interfaces

        private int[] interfaces

      • fields

        private Field[] fields

      • methods

        private Method[] methods

      • is_zip

        private final boolean is_zip

    • Constructor Detail

      • ClassParser

        public ClassParser​(java.io.InputStream inputStream,
                   java.lang.String file_name)
        Parses class from the given stream.
        Parameters:
        inputStream - Input stream
        file_name - File name

      • ClassParser

        public ClassParser​(java.lang.String file_name)
        Parses class from given .class file.
        Parameters:
        file_name - file name

      • ClassParser

        public ClassParser​(java.lang.String zip_file,
                   java.lang.String file_name)
        Parses class from given .class file in a ZIP-archive
        Parameters:
        zip_file - zip file name
        file_name - file name

    • Method Detail

      • parse

        public JavaClass parse()
                throws java.io.IOException,
                       ClassFormatException
        Parses the given Java class file and return an object that represents the contained data, i.e., constants, methods, fields and commands. A ClassFormatException is raised, if the file is not a valid .class file. (This does not include verification of the byte code as it is performed by the java interpreter).
        Returns:
        Class object representing the parsed class file
        Throws:
        java.io.IOException
        ClassFormatException

      • readFields

        private void readFields()
                 throws java.io.IOException,
                        ClassFormatException
        Reads information about the fields of the class, i.e., its variables.
        Throws:
        java.io.IOException
        ClassFormatException

      • readID

        private void readID()
             throws java.io.IOException,
                    ClassFormatException
        Checks whether the header of the file is ok. Of course, this has to be the first action on successive file reads.
        Throws:
        java.io.IOException
        ClassFormatException

      • readInterfaces

        private void readInterfaces()
                     throws java.io.IOException,
                            ClassFormatException
        Reads information about the interfaces implemented by this class.
        Throws:
        java.io.IOException
        ClassFormatException

      • readVersion

        private void readVersion()
                  throws java.io.IOException,
                         ClassFormatException
        Reads major and minor version of compiler which created the file.
        Throws:
        java.io.IOException
        ClassFormatException