jaxp/src/java.xml/share/classes/com/sun/org/apache/bcel/internal/classfile/ClassParser.java - platform/libcore - Git at Google

 /*
  * reserved comment block
  * DO NOT REMOVE OR ALTER!
  */
 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.sun.org.apache.bcel.internal.classfile;


 import  com.sun.org.apache.bcel.internal.Constants;
 import  java.io.*;
 import  java.util.zip.*;

 /**
  * Wrapper class that parses a given Java .class file. The method <A
  * href ="#parse">parse</A> returns a <A href ="JavaClass.html">
  * JavaClass</A> 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 <A href="ftp://java.sun.com/docs/specs/vmspec.ps">
  * JVM specification 1.0</a>. See this paper for
  * further details about the structure of a bytecode file.
  *
  * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
  */
 public final class ClassParser {
   private DataInputStream file;
   private ZipFile         zip;
   private String          file_name;
   private int             class_name_index, superclass_name_index;
   private int             major, minor; // Compiler version
   private int             access_flags; // Access rights of parsed class
   private int[]           interfaces; // Names of implemented interfaces
   private ConstantPool    constant_pool; // collection of constants
   private Field[]         fields; // class fields, i.e., its variables
   private Method[]        methods; // methods defined in the class
   private Attribute[]     attributes; // attributes defined in the class
   private boolean         is_zip; // Loaded from zip file

   private static final int BUFSIZE = 8192;

   /**
    * Parse class from the given stream.
    *
    * @param file Input stream
    * @param file_name File name
    */
   public ClassParser(InputStream file, String file_name) {
     this.file_name = file_name;

     String clazz = file.getClass().getName(); // Not a very clean solution ...
     is_zip = clazz.startsWith("java.util.zip.") || clazz.startsWith("java.util.jar.");

     if(file instanceof DataInputStream) // Is already a data stream
       this.file = (DataInputStream)file;
     else
       this.file = new DataInputStream(new BufferedInputStream(file, BUFSIZE));
   }

   /** Parse class from given .class file.
    *
    * @param file_name file name
    * @throws IOException
    */
   public ClassParser(String file_name) throws IOException
   {
     is_zip = false;
     this.file_name = file_name;
     file = new DataInputStream(new BufferedInputStream
                                (new FileInputStream(file_name), BUFSIZE));
   }

   /** Parse class from given .class file in a ZIP-archive
    *
    * @param file_name file name
    * @throws IOException
    */
   public ClassParser(String zip_file, String file_name) throws IOException
   {
     is_zip = true;
     zip = new ZipFile(zip_file);
     ZipEntry entry = zip.getEntry(file_name);

     this.file_name = file_name;

     file = new DataInputStream(new BufferedInputStream(zip.getInputStream(entry),
                                                        BUFSIZE));
   }

   /**
    * Parse the given Java class file and return an object that represents
    * the contained data, i.e., constants, methods, fields and commands.
    * A <em>ClassFormatException</em> 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).
    *
    * @return Class object representing the parsed class file
    * @throws  IOException
    * @throws  ClassFormatException
    */
   public JavaClass parse() throws IOException, ClassFormatException
   {
     /****************** Read headers ********************************/
     // Check magic tag of class file
     readID();

     // Get compiler version
     readVersion();

     /****************** Read constant pool and related **************/
     // Read constant pool entries
     readConstantPool();

     // Get class information
     readClassInfo();

     // Get interface information, i.e., implemented interfaces
     readInterfaces();

     /****************** Read class fields and methods ***************/
     // Read class fields, i.e., the variables of the class
     readFields();

     // Read class methods, i.e., the functions in the class
     readMethods();

     // Read class attributes
     readAttributes();

     // Check for unknown variables
     //Unknown[] u = Unknown.getUnknownAttributes();
     //for(int i=0; i < u.length; i++)
     //  System.err.println("WARNING: " + u[i]);

     // Everything should have been read now
     //      if(file.available() > 0) {
     //        int bytes = file.available();
     //        byte[] buf = new byte[bytes];
     //        file.read(buf);

     //        if(!(is_zip && (buf.length == 1))) {
     //          System.err.println("WARNING: Trailing garbage at end of " + file_name);
     //          System.err.println(bytes + " extra bytes: " + Utility.toHexString(buf));
     //        }
     //      }

     // Read everything of interest, so close the file
     file.close();
     if(zip != null)
       zip.close();

     // Return the information we have gathered in a new object
     return new JavaClass(class_name_index, superclass_name_index,
                          file_name, major, minor, access_flags,
                          constant_pool, interfaces, fields,
                          methods, attributes, is_zip? JavaClass.ZIP : JavaClass.FILE);
   }

   /**
    * Read information about the attributes of the class.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readAttributes() throws IOException, ClassFormatException
   {
     int attributes_count;

     attributes_count = file.readUnsignedShort();
     attributes       = new Attribute[attributes_count];

     for(int i=0; i < attributes_count; i++)
       attributes[i] = Attribute.readAttribute(file, constant_pool);
   }

   /**
    * Read information about the class and its super class.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readClassInfo() throws IOException, ClassFormatException
   {
     access_flags = file.readUnsignedShort();

     /* Interfaces are implicitely abstract, the flag should be set
      * according to the JVM specification.
      */
     if((access_flags & Constants.ACC_INTERFACE) != 0)
       access_flags |= Constants.ACC_ABSTRACT;

     if(((access_flags & Constants.ACC_ABSTRACT) != 0) &&
        ((access_flags & Constants.ACC_FINAL)    != 0 ))
       throw new ClassFormatException("Class can't be both final and abstract");

     class_name_index      = file.readUnsignedShort();
     superclass_name_index = file.readUnsignedShort();
   }
   /**
    * Read constant pool entries.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readConstantPool() throws IOException, ClassFormatException
   {
     constant_pool = new ConstantPool(file);
   }

   /**
    * Read information about the fields of the class, i.e., its variables.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readFields() throws IOException, ClassFormatException
   {
     int fields_count;

     fields_count = file.readUnsignedShort();
     fields       = new Field[fields_count];

     for(int i=0; i < fields_count; i++)
       fields[i] = new Field(file, constant_pool);
   }

   /******************** Private utility methods **********************/

   /**
    * Check whether the header of the file is ok.
    * Of course, this has to be the first action on successive file reads.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readID() throws IOException, ClassFormatException
   {
     int magic = 0xCAFEBABE;

     if(file.readInt() != magic)
       throw new ClassFormatException(file_name + " is not a Java .class file");
   }
   /**
    * Read information about the interfaces implemented by this class.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readInterfaces() throws IOException, ClassFormatException
   {
     int interfaces_count;

     interfaces_count = file.readUnsignedShort();
     interfaces       = new int[interfaces_count];

     for(int i=0; i < interfaces_count; i++)
       interfaces[i] = file.readUnsignedShort();
   }
   /**
    * Read information about the methods of the class.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readMethods() throws IOException, ClassFormatException
   {
     int methods_count;

     methods_count = file.readUnsignedShort();
     methods       = new Method[methods_count];

     for(int i=0; i < methods_count; i++)
       methods[i] = new Method(file, constant_pool);
   }
   /**
    * Read major and minor version of compiler which created the file.
    * @throws  IOException
    * @throws  ClassFormatException
    */
   private final void readVersion() throws IOException, ClassFormatException
   {
     minor = file.readUnsignedShort();
     major = file.readUnsignedShort();
   }
 }
	/*
	* reserved comment block
	* DO NOT REMOVE OR ALTER!
	*/
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.sun.org.apache.bcel.internal.classfile;


	import com.sun.org.apache.bcel.internal.Constants;
	import java.io.*;
	import java.util.zip.*;

	/**
	* Wrapper class that parses a given Java .class file. The method <A
	* href ="#parse">parse</A> returns a <A href ="JavaClass.html">
	* JavaClass</A> 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 <A href="ftp://java.sun.com/docs/specs/vmspec.ps">
	* JVM specification 1.0</a>. See this paper for
	* further details about the structure of a bytecode file.
	*
	* @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
	*/
	public final class ClassParser {
	private DataInputStream file;
	private ZipFile zip;
	private String file_name;
	private int class_name_index, superclass_name_index;
	private int major, minor; // Compiler version
	private int access_flags; // Access rights of parsed class
	private int[] interfaces; // Names of implemented interfaces
	private ConstantPool constant_pool; // collection of constants
	private Field[] fields; // class fields, i.e., its variables
	private Method[] methods; // methods defined in the class
	private Attribute[] attributes; // attributes defined in the class
	private boolean is_zip; // Loaded from zip file

	private static final int BUFSIZE = 8192;

	/**
	* Parse class from the given stream.
	*
	* @param file Input stream
	* @param file_name File name
	*/
	public ClassParser(InputStream file, String file_name) {
	this.file_name = file_name;

	String clazz = file.getClass().getName(); // Not a very clean solution ...
	is_zip = clazz.startsWith("java.util.zip.") \|\| clazz.startsWith("java.util.jar.");

	if(file instanceof DataInputStream) // Is already a data stream
	this.file = (DataInputStream)file;
	else
	this.file = new DataInputStream(new BufferedInputStream(file, BUFSIZE));
	}

	/** Parse class from given .class file.
	*
	* @param file_name file name
	* @throws IOException
	*/
	public ClassParser(String file_name) throws IOException
	{
	is_zip = false;
	this.file_name = file_name;
	file = new DataInputStream(new BufferedInputStream
	(new FileInputStream(file_name), BUFSIZE));
	}

	/** Parse class from given .class file in a ZIP-archive
	*
	* @param file_name file name
	* @throws IOException
	*/
	public ClassParser(String zip_file, String file_name) throws IOException
	{
	is_zip = true;
	zip = new ZipFile(zip_file);
	ZipEntry entry = zip.getEntry(file_name);

	this.file_name = file_name;

	file = new DataInputStream(new BufferedInputStream(zip.getInputStream(entry),
	BUFSIZE));
	}

	/**
	* Parse the given Java class file and return an object that represents
	* the contained data, i.e., constants, methods, fields and commands.
	* A <em>ClassFormatException</em> 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).
	*
	* @return Class object representing the parsed class file
	* @throws IOException
	* @throws ClassFormatException
	*/
	public JavaClass parse() throws IOException, ClassFormatException
	{
	/**************** Read headers ******************************/
	// Check magic tag of class file
	readID();

	// Get compiler version
	readVersion();

	/**************** Read constant pool and related ************/
	// Read constant pool entries
	readConstantPool();

	// Get class information
	readClassInfo();

	// Get interface information, i.e., implemented interfaces
	readInterfaces();

	/**************** Read class fields and methods *************/
	// Read class fields, i.e., the variables of the class
	readFields();

	// Read class methods, i.e., the functions in the class
	readMethods();

	// Read class attributes
	readAttributes();

	// Check for unknown variables
	//Unknown[] u = Unknown.getUnknownAttributes();
	//for(int i=0; i < u.length; i++)
	// System.err.println("WARNING: " + u[i]);

	// Everything should have been read now
	// if(file.available() > 0) {
	// int bytes = file.available();
	// byte[] buf = new byte[bytes];
	// file.read(buf);

	// if(!(is_zip && (buf.length == 1))) {
	// System.err.println("WARNING: Trailing garbage at end of " + file_name);
	// System.err.println(bytes + " extra bytes: " + Utility.toHexString(buf));
	// }
	// }

	// Read everything of interest, so close the file
	file.close();
	if(zip != null)
	zip.close();

	// Return the information we have gathered in a new object
	return new JavaClass(class_name_index, superclass_name_index,
	file_name, major, minor, access_flags,
	constant_pool, interfaces, fields,
	methods, attributes, is_zip? JavaClass.ZIP : JavaClass.FILE);
	}

	/**
	* Read information about the attributes of the class.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readAttributes() throws IOException, ClassFormatException
	{
	int attributes_count;

	attributes_count = file.readUnsignedShort();
	attributes = new Attribute[attributes_count];

	for(int i=0; i < attributes_count; i++)
	attributes[i] = Attribute.readAttribute(file, constant_pool);
	}

	/**
	* Read information about the class and its super class.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readClassInfo() throws IOException, ClassFormatException
	{
	access_flags = file.readUnsignedShort();

	/* Interfaces are implicitely abstract, the flag should be set
	* according to the JVM specification.
	*/
	if((access_flags & Constants.ACC_INTERFACE) != 0)
	access_flags \|= Constants.ACC_ABSTRACT;

	if(((access_flags & Constants.ACC_ABSTRACT) != 0) &&
	((access_flags & Constants.ACC_FINAL) != 0 ))
	throw new ClassFormatException("Class can't be both final and abstract");

	class_name_index = file.readUnsignedShort();
	superclass_name_index = file.readUnsignedShort();
	}
	/**
	* Read constant pool entries.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readConstantPool() throws IOException, ClassFormatException
	{
	constant_pool = new ConstantPool(file);
	}

	/**
	* Read information about the fields of the class, i.e., its variables.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readFields() throws IOException, ClassFormatException
	{
	int fields_count;

	fields_count = file.readUnsignedShort();
	fields = new Field[fields_count];

	for(int i=0; i < fields_count; i++)
	fields[i] = new Field(file, constant_pool);
	}

	/****************** Private utility methods ********************/

	/**
	* Check whether the header of the file is ok.
	* Of course, this has to be the first action on successive file reads.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readID() throws IOException, ClassFormatException
	{
	int magic = 0xCAFEBABE;

	if(file.readInt() != magic)
	throw new ClassFormatException(file_name + " is not a Java .class file");
	}
	/**
	* Read information about the interfaces implemented by this class.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readInterfaces() throws IOException, ClassFormatException
	{
	int interfaces_count;

	interfaces_count = file.readUnsignedShort();
	interfaces = new int[interfaces_count];

	for(int i=0; i < interfaces_count; i++)
	interfaces[i] = file.readUnsignedShort();
	}
	/**
	* Read information about the methods of the class.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readMethods() throws IOException, ClassFormatException
	{
	int methods_count;

	methods_count = file.readUnsignedShort();
	methods = new Method[methods_count];

	for(int i=0; i < methods_count; i++)
	methods[i] = new Method(file, constant_pool);
	}
	/**
	* Read major and minor version of compiler which created the file.
	* @throws IOException
	* @throws ClassFormatException
	*/
	private final void readVersion() throws IOException, ClassFormatException
	{
	minor = file.readUnsignedShort();
	major = file.readUnsignedShort();
	}
	}