bundles/org.eclipse.equinox.p2.repository.tools/src/org/eclipse/equinox/p2/internal/repository/comparator/java/ClassFileReader.java - equinox/rt.equinox.p2 - Git at Google

 /*******************************************************************************
  * Copyright (c) 2009 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.equinox.p2.internal.repository.comparator.java;

 import java.util.Arrays;

 public class ClassFileReader extends ClassFileStruct {
 	/*
 	 * This value should be used to read completely each part of a .class file.
 	 */
 	public static final int ALL = 0xFFFF;

 	/*
 	 * This value should be used to read only the constant pool entries of a .class file.
 	 */
 	public static final int CONSTANT_POOL = 0x0001;

 	/*
 	 * This value should be used to read the constant pool entries and
 	 * the method infos of a .class file.
 	 */
 	public static final int METHOD_INFOS = 0x0002 + CONSTANT_POOL;

 	/*
 	 * This value should be used to read the constant pool entries and
 	 * the field infos of a .class file.
 	 */
 	public static final int FIELD_INFOS = 0x0004 + CONSTANT_POOL;

 	/*
 	 * This value should be used to read the constant pool entries and
 	 * the super interface names of a .class file.
 	 */
 	public static final int SUPER_INTERFACES = 0x0008 + CONSTANT_POOL;

 	/*
 	 * This value should be used to read the constant pool entries and
 	 * the attributes of a .class file.
 	 */
 	public static final int CLASSFILE_ATTRIBUTES = 0x0010 + CONSTANT_POOL;

 	/*
 	 * This value should be used to read the method bodies.
 	 * It has to be used with METHOD_INFOS.
 	 */
 	public static final int METHOD_BODIES = 0x0020;

 	/*
 	 * This value should be used to read the whole contents of the .class file except the
 	 * method bodies.
 	 */
 	public static final int ALL_BUT_METHOD_BODIES = ALL & ~METHOD_BODIES;

 	private static final FieldInfo[] NO_FIELD_INFOS = new FieldInfo[0];
 	private static final char[][] NO_INTERFACES_NAMES = CharOperation.NO_CHAR_CHAR;
 	private static final MethodInfo[] NO_METHOD_INFOS = new MethodInfo[0];
 	private int accessFlags;
 	private ClassFileAttribute[] attributes;
 	private int attributesCount;
 	private char[] className;
 	private int classNameIndex;

 	private ConstantPool constantPool;
 	private FieldInfo[] fields;
 	private int fieldsCount;
 	private InnerClassesAttribute innerClassesAttribute;
 	private int[] interfaceIndexes;
 	private char[][] interfaceNames;
 	private int interfacesCount;
 	private int magicNumber;
 	private int majorVersion;
 	private MethodInfo[] methods;
 	private int methodsCount;
 	private int minorVersion;
 	private SourceFileAttribute sourceFileAttribute;
 	private char[] superclassName;
 	private int superclassNameIndex;

 	/*
 	 * Constructor for ClassFileReader.
 	 *
 	 * @param classFileBytes the raw bytes of the .class file
 	 * @param decodingFlags the decoding flags
 	 *
 	 * @see IClassFileReader#ALL
 	 * @see IClassFileReader#CLASSFILE_ATTRIBUTES
 	 * @see IClassFileReader#CONSTANT_POOL
 	 * @see IClassFileReader#FIELD_INFOS
 	 */
 	public ClassFileReader(byte[] classFileBytes, int decodingFlags) throws ClassFormatException {

 		// This method looks ugly but is actually quite simple, the constantPool is constructed
 		// in 3 passes.  All non-primitive constant pool members that usually refer to other members
 		// by index are tweaked to have their value in inst vars, this minor cost at read-time makes
 		// all subsequent uses of the constant pool element faster.
 		int constantPoolCount;
 		int[] constantPoolOffsets;
 		try {
 			this.magicNumber = (int) u4At(classFileBytes, 0, 0);
 			if (this.magicNumber != 0xCAFEBABE) {
 				throw new ClassFormatException(ClassFormatException.INVALID_MAGIC_NUMBER);
 			}

 			int readOffset = 10;
 			this.minorVersion = u2At(classFileBytes, 4, 0);
 			this.majorVersion = u2At(classFileBytes, 6, 0);

 			if ((decodingFlags & CONSTANT_POOL) == 0) {
 				// no need to go further
 				return;
 			}

 			constantPoolCount = u2At(classFileBytes, 8, 0);
 			// Pass #1 - Fill in all primitive constants
 			constantPoolOffsets = new int[constantPoolCount];
 			for (int i = 1; i < constantPoolCount; i++) {
 				int tag = u1At(classFileBytes, readOffset, 0);
 				switch (tag) {
 					case ConstantPoolConstant.CONSTANT_Utf8 :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += u2At(classFileBytes, readOffset + 1, 0);
 						readOffset += ConstantPoolConstant.CONSTANT_Utf8_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_Integer :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_Integer_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_Float :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_Float_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_Long :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_Long_SIZE;
 						i++;
 						break;
 					case ConstantPoolConstant.CONSTANT_Double :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_Double_SIZE;
 						i++;
 						break;
 					case ConstantPoolConstant.CONSTANT_Class :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_Class_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_String :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_String_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_Fieldref :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_Fieldref_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_Methodref :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_Methodref_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_InterfaceMethodref :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_InterfaceMethodref_SIZE;
 						break;
 					case ConstantPoolConstant.CONSTANT_NameAndType :
 						constantPoolOffsets[i] = readOffset;
 						readOffset += ConstantPoolConstant.CONSTANT_NameAndType_SIZE;
 						break;
 					default :
 						throw new ClassFormatException(ClassFormatException.INVALID_TAG_CONSTANT);
 				}
 			}

 			this.constantPool = new ConstantPool(classFileBytes, constantPoolOffsets);
 			// Read and validate access flags
 			this.accessFlags = u2At(classFileBytes, readOffset, 0);
 			readOffset += 2;

 			// Read the classname, use exception handlers to catch bad format
 			this.classNameIndex = u2At(classFileBytes, readOffset, 0);
 			this.className = getConstantClassNameAt(classFileBytes, constantPoolOffsets, this.classNameIndex);
 			readOffset += 2;

 			// Read the superclass name, can be zero for java.lang.Object
 			this.superclassNameIndex = u2At(classFileBytes, readOffset, 0);
 			readOffset += 2;
 			// if superclassNameIndex is equals to 0 there is no need to set a value for the
 			// field this.superclassName. null is fine.
 			if (this.superclassNameIndex != 0) {
 				this.superclassName = getConstantClassNameAt(classFileBytes, constantPoolOffsets, this.superclassNameIndex);
 			}

 			// Read the interfaces, use exception handlers to catch bad format
 			this.interfacesCount = u2At(classFileBytes, readOffset, 0);
 			readOffset += 2;
 			this.interfaceNames = NO_INTERFACES_NAMES;
 			this.interfaceIndexes = Utility.EMPTY_INT_ARRAY;
 			if (this.interfacesCount != 0) {
 				if ((decodingFlags & SUPER_INTERFACES) != CONSTANT_POOL) {
 					this.interfaceNames = new char[this.interfacesCount][];
 					this.interfaceIndexes = new int[this.interfacesCount];
 					for (int i = 0; i < this.interfacesCount; i++) {
 						this.interfaceIndexes[i] = u2At(classFileBytes, readOffset, 0);
 						this.interfaceNames[i] = getConstantClassNameAt(classFileBytes, constantPoolOffsets, this.interfaceIndexes[i]);
 						readOffset += 2;
 					}
 				} else {
 					readOffset += (2 * this.interfacesCount);
 				}
 			}
 			// Read the this.fields, use exception handlers to catch bad format
 			this.fieldsCount = u2At(classFileBytes, readOffset, 0);
 			readOffset += 2;
 			this.fields = NO_FIELD_INFOS;
 			if (this.fieldsCount != 0) {
 				if ((decodingFlags & FIELD_INFOS) != CONSTANT_POOL) {
 					FieldInfo field;
 					this.fields = new FieldInfo[this.fieldsCount];
 					for (int i = 0; i < this.fieldsCount; i++) {
 						field = new FieldInfo(classFileBytes, this.constantPool, readOffset);
 						this.fields[i] = field;
 						readOffset += field.sizeInBytes();
 					}
 				} else {
 					for (int i = 0; i < this.fieldsCount; i++) {
 						int attributeCountForField = u2At(classFileBytes, 6, readOffset);
 						readOffset += 8;
 						if (attributeCountForField != 0) {
 							for (int j = 0; j < attributeCountForField; j++) {
 								int attributeLength = (int) u4At(classFileBytes, 2, readOffset);
 								readOffset += (6 + attributeLength);
 							}
 						}
 					}
 				}
 			}
 			// Read the this.methods
 			this.methodsCount = u2At(classFileBytes, readOffset, 0);
 			readOffset += 2;
 			this.methods = NO_METHOD_INFOS;
 			if (this.methodsCount != 0) {
 				if ((decodingFlags & METHOD_INFOS) != CONSTANT_POOL) {
 					this.methods = new MethodInfo[this.methodsCount];
 					MethodInfo method;
 					for (int i = 0; i < this.methodsCount; i++) {
 						method = new MethodInfo(classFileBytes, this.constantPool, readOffset, decodingFlags);
 						this.methods[i] = method;
 						readOffset += method.sizeInBytes();
 					}
 				} else {
 					for (int i = 0; i < this.methodsCount; i++) {
 						int attributeCountForMethod = u2At(classFileBytes, 6, readOffset);
 						readOffset += 8;
 						if (attributeCountForMethod != 0) {
 							for (int j = 0; j < attributeCountForMethod; j++) {
 								int attributeLength = (int) u4At(classFileBytes, 2, readOffset);
 								readOffset += (6 + attributeLength);
 							}
 						}
 					}
 				}
 			}

 			// Read the attributes
 			this.attributesCount = u2At(classFileBytes, readOffset, 0);
 			readOffset += 2;

 			int attributesIndex = 0;
 			this.attributes = ClassFileAttribute.NO_ATTRIBUTES;
 			if (this.attributesCount != 0) {
 				if ((decodingFlags & CLASSFILE_ATTRIBUTES) != CONSTANT_POOL) {
 					this.attributes = new ClassFileAttribute[this.attributesCount];
 					for (int i = 0; i < this.attributesCount; i++) {
 						int utf8Offset = constantPoolOffsets[u2At(classFileBytes, readOffset, 0)];
 						char[] attributeName = utf8At(classFileBytes, utf8Offset + 3, 0, u2At(classFileBytes, utf8Offset + 1, 0));
 						if (Arrays.equals(attributeName, AttributeNamesConstants.INNER_CLASSES)) {
 							this.innerClassesAttribute = new InnerClassesAttribute(classFileBytes, this.constantPool, readOffset);
 							this.attributes[attributesIndex++] = this.innerClassesAttribute;
 						} else if (Arrays.equals(attributeName, AttributeNamesConstants.SOURCE)) {
 							this.sourceFileAttribute = new SourceFileAttribute(classFileBytes, this.constantPool, readOffset);
 							this.attributes[attributesIndex++] = this.sourceFileAttribute;
 						} else if (Arrays.equals(attributeName, AttributeNamesConstants.ENCLOSING_METHOD)) {
 							this.attributes[attributesIndex++] = new EnclosingMethodAttribute(classFileBytes, this.constantPool, readOffset);
 						} else if (Arrays.equals(attributeName, AttributeNamesConstants.SIGNATURE)) {
 							this.attributes[attributesIndex++] = new SignatureAttribute(classFileBytes, this.constantPool, readOffset);
 						} else if (Arrays.equals(attributeName, AttributeNamesConstants.RUNTIME_VISIBLE_ANNOTATIONS)) {
 							this.attributes[attributesIndex++] = new RuntimeVisibleAnnotationsAttribute(classFileBytes, this.constantPool, readOffset);
 						} else if (Arrays.equals(attributeName, AttributeNamesConstants.RUNTIME_INVISIBLE_ANNOTATIONS)) {
 							this.attributes[attributesIndex++] = new RuntimeInvisibleAnnotationsAttribute(classFileBytes, this.constantPool, readOffset);
 						} else {
 							this.attributes[attributesIndex++] = new ClassFileAttribute(classFileBytes, this.constantPool, readOffset);
 						}
 						readOffset += (6 + u4At(classFileBytes, readOffset + 2, 0));
 					}
 				} else {
 					for (int i = 0; i < this.attributesCount; i++) {
 						readOffset += (6 + u4At(classFileBytes, readOffset + 2, 0));
 					}
 				}
 			}
 			if (readOffset != classFileBytes.length) {
 				throw new ClassFormatException(ClassFormatException.TOO_MANY_BYTES);
 			}
 		} catch (ClassFormatException e) {
 			throw e;
 		} catch (Exception e) {
 			e.printStackTrace();
 			throw new ClassFormatException(ClassFormatException.ERROR_TRUNCATED_INPUT);
 		}
 	}

 	/*
 	 * @see IClassFileReader#getAccessFlags()
 	 */
 	public int getAccessFlags() {
 		return this.accessFlags;
 	}

 	/*
 	 * @see IClassFileReader#getAttributeCount()
 	 */
 	public int getAttributeCount() {
 		return this.attributesCount;
 	}

 	/*
 	 * @see IClassFileReader#getAttributes()
 	 */
 	public ClassFileAttribute[] getAttributes() {
 		return this.attributes;
 	}

 	/*
 	 * @see IClassFileReader#getClassIndex()
 	 */
 	public int getClassIndex() {
 		return this.classNameIndex;
 	}

 	/*
 	 * @see IClassFileReader#getClassName()
 	 */
 	public char[] getClassName() {
 		return this.className;
 	}

 	private char[] getConstantClassNameAt(byte[] classFileBytes, int[] constantPoolOffsets, int constantPoolIndex) {
 		int utf8Offset = constantPoolOffsets[u2At(classFileBytes, constantPoolOffsets[constantPoolIndex] + 1, 0)];
 		return utf8At(classFileBytes, utf8Offset + 3, 0, u2At(classFileBytes, utf8Offset + 1, 0));
 	}

 	/*
 	 * @see IClassFileReader#getConstantPool()
 	 */
 	public ConstantPool getConstantPool() {
 		return this.constantPool;
 	}

 	/*
 	 * @see IClassFileReader#getFieldInfos()
 	 */
 	public FieldInfo[] getFieldInfos() {
 		return this.fields;
 	}

 	/*
 	 * @see IClassFileReader#getFieldsCount()
 	 */
 	public int getFieldsCount() {
 		return this.fieldsCount;
 	}

 	/*
 	 * @see IClassFileReader#getInnerClassesAttribute()
 	 */
 	public InnerClassesAttribute getInnerClassesAttribute() {
 		return this.innerClassesAttribute;
 	}

 	/*
 	 * @see IClassFileReader#getInterfaceIndexes()
 	 */
 	public int[] getInterfaceIndexes() {
 		return this.interfaceIndexes;
 	}

 	/*
 	 * @see IClassFileReader#getInterfaceNames()
 	 */
 	public char[][] getInterfaceNames() {
 		return this.interfaceNames;
 	}

 	/*
 	 * @see IClassFileReader#getMagic()
 	 */
 	public int getMagic() {
 		return this.magicNumber;
 	}

 	/*
 	 * @see IClassFileReader#getMajorVersion()
 	 */
 	public int getMajorVersion() {
 		return this.majorVersion;
 	}

 	/*
 	 * @see IClassFileReader#getMethodInfos()
 	 */
 	public MethodInfo[] getMethodInfos() {
 		return this.methods;
 	}

 	/*
 	 * @see IClassFileReader#getMethodsCount()
 	 */
 	public int getMethodsCount() {
 		return this.methodsCount;
 	}

 	/*
 	 * @see IClassFileReader#getMinorVersion()
 	 */
 	public int getMinorVersion() {
 		return this.minorVersion;
 	}

 	/*
 	 * @see IClassFileReader#getSourceFileAttribute()
 	 */
 	public SourceFileAttribute getSourceFileAttribute() {
 		return this.sourceFileAttribute;
 	}

 	/*
 	 * @see IClassFileReader#getSuperclassIndex()
 	 */
 	public int getSuperclassIndex() {
 		return this.superclassNameIndex;
 	}

 	/*
 	 * @see IClassFileReader#getSuperclassName()
 	 */
 	public char[] getSuperclassName() {
 		return this.superclassName;
 	}

 	/*
 	 * @see IClassFileReader#isClass()
 	 */
 	public boolean isClass() {
 		return !isInterface();
 	}

 	/*
 	 * @see IClassFileReader#isInterface()
 	 */
 	public boolean isInterface() {
 		return (getAccessFlags() & IModifierConstants.ACC_INTERFACE) != 0;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2009 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.equinox.p2.internal.repository.comparator.java;

	import java.util.Arrays;

	public class ClassFileReader extends ClassFileStruct {
	/*
	* This value should be used to read completely each part of a .class file.
	*/
	public static final int ALL = 0xFFFF;

	/*
	* This value should be used to read only the constant pool entries of a .class file.
	*/
	public static final int CONSTANT_POOL = 0x0001;

	/*
	* This value should be used to read the constant pool entries and
	* the method infos of a .class file.
	*/
	public static final int METHOD_INFOS = 0x0002 + CONSTANT_POOL;

	/*
	* This value should be used to read the constant pool entries and
	* the field infos of a .class file.
	*/
	public static final int FIELD_INFOS = 0x0004 + CONSTANT_POOL;

	/*
	* This value should be used to read the constant pool entries and
	* the super interface names of a .class file.
	*/
	public static final int SUPER_INTERFACES = 0x0008 + CONSTANT_POOL;

	/*
	* This value should be used to read the constant pool entries and
	* the attributes of a .class file.
	*/
	public static final int CLASSFILE_ATTRIBUTES = 0x0010 + CONSTANT_POOL;

	/*
	* This value should be used to read the method bodies.
	* It has to be used with METHOD_INFOS.
	*/
	public static final int METHOD_BODIES = 0x0020;

	/*
	* This value should be used to read the whole contents of the .class file except the
	* method bodies.
	*/
	public static final int ALL_BUT_METHOD_BODIES = ALL & ~METHOD_BODIES;

	private static final FieldInfo[] NO_FIELD_INFOS = new FieldInfo[0];
	private static final char[][] NO_INTERFACES_NAMES = CharOperation.NO_CHAR_CHAR;
	private static final MethodInfo[] NO_METHOD_INFOS = new MethodInfo[0];
	private int accessFlags;
	private ClassFileAttribute[] attributes;
	private int attributesCount;
	private char[] className;
	private int classNameIndex;

	private ConstantPool constantPool;
	private FieldInfo[] fields;
	private int fieldsCount;
	private InnerClassesAttribute innerClassesAttribute;
	private int[] interfaceIndexes;
	private char[][] interfaceNames;
	private int interfacesCount;
	private int magicNumber;
	private int majorVersion;
	private MethodInfo[] methods;
	private int methodsCount;
	private int minorVersion;
	private SourceFileAttribute sourceFileAttribute;
	private char[] superclassName;
	private int superclassNameIndex;

	/*
	* Constructor for ClassFileReader.
	*
	* @param classFileBytes the raw bytes of the .class file
	* @param decodingFlags the decoding flags
	*
	* @see IClassFileReader#ALL
	* @see IClassFileReader#CLASSFILE_ATTRIBUTES
	* @see IClassFileReader#CONSTANT_POOL
	* @see IClassFileReader#FIELD_INFOS
	*/
	public ClassFileReader(byte[] classFileBytes, int decodingFlags) throws ClassFormatException {

	// This method looks ugly but is actually quite simple, the constantPool is constructed
	// in 3 passes. All non-primitive constant pool members that usually refer to other members
	// by index are tweaked to have their value in inst vars, this minor cost at read-time makes
	// all subsequent uses of the constant pool element faster.
	int constantPoolCount;
	int[] constantPoolOffsets;
	try {
	this.magicNumber = (int) u4At(classFileBytes, 0, 0);
	if (this.magicNumber != 0xCAFEBABE) {
	throw new ClassFormatException(ClassFormatException.INVALID_MAGIC_NUMBER);
	}

	int readOffset = 10;
	this.minorVersion = u2At(classFileBytes, 4, 0);
	this.majorVersion = u2At(classFileBytes, 6, 0);

	if ((decodingFlags & CONSTANT_POOL) == 0) {
	// no need to go further
	return;
	}

	constantPoolCount = u2At(classFileBytes, 8, 0);
	// Pass #1 - Fill in all primitive constants
	constantPoolOffsets = new int[constantPoolCount];
	for (int i = 1; i < constantPoolCount; i++) {
	int tag = u1At(classFileBytes, readOffset, 0);
	switch (tag) {
	case ConstantPoolConstant.CONSTANT_Utf8 :
	constantPoolOffsets[i] = readOffset;
	readOffset += u2At(classFileBytes, readOffset + 1, 0);
	readOffset += ConstantPoolConstant.CONSTANT_Utf8_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_Integer :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_Integer_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_Float :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_Float_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_Long :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_Long_SIZE;
	i++;
	break;
	case ConstantPoolConstant.CONSTANT_Double :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_Double_SIZE;
	i++;
	break;
	case ConstantPoolConstant.CONSTANT_Class :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_Class_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_String :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_String_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_Fieldref :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_Fieldref_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_Methodref :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_Methodref_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_InterfaceMethodref :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_InterfaceMethodref_SIZE;
	break;
	case ConstantPoolConstant.CONSTANT_NameAndType :
	constantPoolOffsets[i] = readOffset;
	readOffset += ConstantPoolConstant.CONSTANT_NameAndType_SIZE;
	break;
	default :
	throw new ClassFormatException(ClassFormatException.INVALID_TAG_CONSTANT);
	}
	}

	this.constantPool = new ConstantPool(classFileBytes, constantPoolOffsets);
	// Read and validate access flags
	this.accessFlags = u2At(classFileBytes, readOffset, 0);
	readOffset += 2;

	// Read the classname, use exception handlers to catch bad format
	this.classNameIndex = u2At(classFileBytes, readOffset, 0);
	this.className = getConstantClassNameAt(classFileBytes, constantPoolOffsets, this.classNameIndex);
	readOffset += 2;

	// Read the superclass name, can be zero for java.lang.Object
	this.superclassNameIndex = u2At(classFileBytes, readOffset, 0);
	readOffset += 2;
	// if superclassNameIndex is equals to 0 there is no need to set a value for the
	// field this.superclassName. null is fine.
	if (this.superclassNameIndex != 0) {
	this.superclassName = getConstantClassNameAt(classFileBytes, constantPoolOffsets, this.superclassNameIndex);
	}

	// Read the interfaces, use exception handlers to catch bad format
	this.interfacesCount = u2At(classFileBytes, readOffset, 0);
	readOffset += 2;
	this.interfaceNames = NO_INTERFACES_NAMES;
	this.interfaceIndexes = Utility.EMPTY_INT_ARRAY;
	if (this.interfacesCount != 0) {
	if ((decodingFlags & SUPER_INTERFACES) != CONSTANT_POOL) {
	this.interfaceNames = new char[this.interfacesCount][];
	this.interfaceIndexes = new int[this.interfacesCount];
	for (int i = 0; i < this.interfacesCount; i++) {
	this.interfaceIndexes[i] = u2At(classFileBytes, readOffset, 0);
	this.interfaceNames[i] = getConstantClassNameAt(classFileBytes, constantPoolOffsets, this.interfaceIndexes[i]);
	readOffset += 2;
	}
	} else {
	readOffset += (2 * this.interfacesCount);
	}
	}
	// Read the this.fields, use exception handlers to catch bad format
	this.fieldsCount = u2At(classFileBytes, readOffset, 0);
	readOffset += 2;
	this.fields = NO_FIELD_INFOS;
	if (this.fieldsCount != 0) {
	if ((decodingFlags & FIELD_INFOS) != CONSTANT_POOL) {
	FieldInfo field;
	this.fields = new FieldInfo[this.fieldsCount];
	for (int i = 0; i < this.fieldsCount; i++) {
	field = new FieldInfo(classFileBytes, this.constantPool, readOffset);
	this.fields[i] = field;
	readOffset += field.sizeInBytes();
	}
	} else {
	for (int i = 0; i < this.fieldsCount; i++) {
	int attributeCountForField = u2At(classFileBytes, 6, readOffset);
	readOffset += 8;
	if (attributeCountForField != 0) {
	for (int j = 0; j < attributeCountForField; j++) {
	int attributeLength = (int) u4At(classFileBytes, 2, readOffset);
	readOffset += (6 + attributeLength);
	}
	}
	}
	}
	}
	// Read the this.methods
	this.methodsCount = u2At(classFileBytes, readOffset, 0);
	readOffset += 2;
	this.methods = NO_METHOD_INFOS;
	if (this.methodsCount != 0) {
	if ((decodingFlags & METHOD_INFOS) != CONSTANT_POOL) {
	this.methods = new MethodInfo[this.methodsCount];
	MethodInfo method;
	for (int i = 0; i < this.methodsCount; i++) {
	method = new MethodInfo(classFileBytes, this.constantPool, readOffset, decodingFlags);
	this.methods[i] = method;
	readOffset += method.sizeInBytes();
	}
	} else {
	for (int i = 0; i < this.methodsCount; i++) {
	int attributeCountForMethod = u2At(classFileBytes, 6, readOffset);
	readOffset += 8;
	if (attributeCountForMethod != 0) {
	for (int j = 0; j < attributeCountForMethod; j++) {
	int attributeLength = (int) u4At(classFileBytes, 2, readOffset);
	readOffset += (6 + attributeLength);
	}
	}
	}
	}
	}

	// Read the attributes
	this.attributesCount = u2At(classFileBytes, readOffset, 0);
	readOffset += 2;

	int attributesIndex = 0;
	this.attributes = ClassFileAttribute.NO_ATTRIBUTES;
	if (this.attributesCount != 0) {
	if ((decodingFlags & CLASSFILE_ATTRIBUTES) != CONSTANT_POOL) {
	this.attributes = new ClassFileAttribute[this.attributesCount];
	for (int i = 0; i < this.attributesCount; i++) {
	int utf8Offset = constantPoolOffsets[u2At(classFileBytes, readOffset, 0)];
	char[] attributeName = utf8At(classFileBytes, utf8Offset + 3, 0, u2At(classFileBytes, utf8Offset + 1, 0));
	if (Arrays.equals(attributeName, AttributeNamesConstants.INNER_CLASSES)) {
	this.innerClassesAttribute = new InnerClassesAttribute(classFileBytes, this.constantPool, readOffset);
	this.attributes[attributesIndex++] = this.innerClassesAttribute;
	} else if (Arrays.equals(attributeName, AttributeNamesConstants.SOURCE)) {
	this.sourceFileAttribute = new SourceFileAttribute(classFileBytes, this.constantPool, readOffset);
	this.attributes[attributesIndex++] = this.sourceFileAttribute;
	} else if (Arrays.equals(attributeName, AttributeNamesConstants.ENCLOSING_METHOD)) {
	this.attributes[attributesIndex++] = new EnclosingMethodAttribute(classFileBytes, this.constantPool, readOffset);
	} else if (Arrays.equals(attributeName, AttributeNamesConstants.SIGNATURE)) {
	this.attributes[attributesIndex++] = new SignatureAttribute(classFileBytes, this.constantPool, readOffset);
	} else if (Arrays.equals(attributeName, AttributeNamesConstants.RUNTIME_VISIBLE_ANNOTATIONS)) {
	this.attributes[attributesIndex++] = new RuntimeVisibleAnnotationsAttribute(classFileBytes, this.constantPool, readOffset);
	} else if (Arrays.equals(attributeName, AttributeNamesConstants.RUNTIME_INVISIBLE_ANNOTATIONS)) {
	this.attributes[attributesIndex++] = new RuntimeInvisibleAnnotationsAttribute(classFileBytes, this.constantPool, readOffset);
	} else {
	this.attributes[attributesIndex++] = new ClassFileAttribute(classFileBytes, this.constantPool, readOffset);
	}
	readOffset += (6 + u4At(classFileBytes, readOffset + 2, 0));
	}
	} else {
	for (int i = 0; i < this.attributesCount; i++) {
	readOffset += (6 + u4At(classFileBytes, readOffset + 2, 0));
	}
	}
	}
	if (readOffset != classFileBytes.length) {
	throw new ClassFormatException(ClassFormatException.TOO_MANY_BYTES);
	}
	} catch (ClassFormatException e) {
	throw e;
	} catch (Exception e) {
	e.printStackTrace();
	throw new ClassFormatException(ClassFormatException.ERROR_TRUNCATED_INPUT);
	}
	}

	/*
	* @see IClassFileReader#getAccessFlags()
	*/
	public int getAccessFlags() {
	return this.accessFlags;
	}

	/*
	* @see IClassFileReader#getAttributeCount()
	*/
	public int getAttributeCount() {
	return this.attributesCount;
	}

	/*
	* @see IClassFileReader#getAttributes()
	*/
	public ClassFileAttribute[] getAttributes() {
	return this.attributes;
	}

	/*
	* @see IClassFileReader#getClassIndex()
	*/
	public int getClassIndex() {
	return this.classNameIndex;
	}

	/*
	* @see IClassFileReader#getClassName()
	*/
	public char[] getClassName() {
	return this.className;
	}

	private char[] getConstantClassNameAt(byte[] classFileBytes, int[] constantPoolOffsets, int constantPoolIndex) {
	int utf8Offset = constantPoolOffsets[u2At(classFileBytes, constantPoolOffsets[constantPoolIndex] + 1, 0)];
	return utf8At(classFileBytes, utf8Offset + 3, 0, u2At(classFileBytes, utf8Offset + 1, 0));
	}

	/*
	* @see IClassFileReader#getConstantPool()
	*/
	public ConstantPool getConstantPool() {
	return this.constantPool;
	}

	/*
	* @see IClassFileReader#getFieldInfos()
	*/
	public FieldInfo[] getFieldInfos() {
	return this.fields;
	}

	/*
	* @see IClassFileReader#getFieldsCount()
	*/
	public int getFieldsCount() {
	return this.fieldsCount;
	}

	/*
	* @see IClassFileReader#getInnerClassesAttribute()
	*/
	public InnerClassesAttribute getInnerClassesAttribute() {
	return this.innerClassesAttribute;
	}

	/*
	* @see IClassFileReader#getInterfaceIndexes()
	*/
	public int[] getInterfaceIndexes() {
	return this.interfaceIndexes;
	}

	/*
	* @see IClassFileReader#getInterfaceNames()
	*/
	public char[][] getInterfaceNames() {
	return this.interfaceNames;
	}

	/*
	* @see IClassFileReader#getMagic()
	*/
	public int getMagic() {
	return this.magicNumber;
	}

	/*
	* @see IClassFileReader#getMajorVersion()
	*/
	public int getMajorVersion() {
	return this.majorVersion;
	}

	/*
	* @see IClassFileReader#getMethodInfos()
	*/
	public MethodInfo[] getMethodInfos() {
	return this.methods;
	}

	/*
	* @see IClassFileReader#getMethodsCount()
	*/
	public int getMethodsCount() {
	return this.methodsCount;
	}

	/*
	* @see IClassFileReader#getMinorVersion()
	*/
	public int getMinorVersion() {
	return this.minorVersion;
	}

	/*
	* @see IClassFileReader#getSourceFileAttribute()
	*/
	public SourceFileAttribute getSourceFileAttribute() {
	return this.sourceFileAttribute;
	}

	/*
	* @see IClassFileReader#getSuperclassIndex()
	*/
	public int getSuperclassIndex() {
	return this.superclassNameIndex;
	}

	/*
	* @see IClassFileReader#getSuperclassName()
	*/
	public char[] getSuperclassName() {
	return this.superclassName;
	}

	/*
	* @see IClassFileReader#isClass()
	*/
	public boolean isClass() {
	return !isInterface();
	}

	/*
	* @see IClassFileReader#isInterface()
	*/
	public boolean isInterface() {
	return (getAccessFlags() & IModifierConstants.ACC_INTERFACE) != 0;
	}
	}