http://www.eclipse.org/jdt: Java Development Tools Core (Eclipse Foundation) 
Copyright (c) 2000, 2018 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation

/*******************************************************************************
 * Copyright (c) 2000, 2018 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import org.eclipse.jdt.core.util.IConstantPool;
import org.eclipse.jdt.core.util.IConstantPoolConstant;
import org.eclipse.jdt.core.util.IConstantPoolEntry;


Default implementation of IConstantPool.

/**
 * Default implementation of IConstantPool.
 */
public class ConstantPool extends ClassFileStruct implements IConstantPool {

	private int constantPoolCount;
	private int[] constantPoolOffset;
	private byte[] classFileBytes;

	ConstantPool(byte[] reference, int[] constantPoolOffset) {
		this.constantPoolCount = constantPoolOffset.length;
		this.constantPoolOffset = constantPoolOffset;
		this.classFileBytes = reference;
	}

	
See Also:
  • decodeEntry.decodeEntry(int)
/**
	 * @see IConstantPool#decodeEntry(int)
	 */
	@Override
	public IConstantPoolEntry decodeEntry(int index) {
		ConstantPoolEntry constantPoolEntry = null;
		int kind = getEntryKind(index);
		switch(kind) {
			case IConstantPoolConstant.CONSTANT_Class :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setClassInfoNameIndex(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				constantPoolEntry.setClassInfoName(getUtf8ValueAt(constantPoolEntry.getClassInfoNameIndex()));
				break;
			case IConstantPoolConstant.CONSTANT_Double :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setDoubleValue(doubleAt(this.classFileBytes, 1, this.constantPoolOffset[index]));
				break;
			case IConstantPoolConstant.CONSTANT_Fieldref :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setClassIndex(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				int declaringClassIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[constantPoolEntry.getClassIndex()]);
				constantPoolEntry.setClassName(getUtf8ValueAt(declaringClassIndex));
				constantPoolEntry.setNameAndTypeIndex(u2At(this.classFileBytes,  3, this.constantPoolOffset[index]));
				int fieldNameIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[constantPoolEntry.getNameAndTypeIndex()]);
				int fieldDescriptorIndex = u2At(this.classFileBytes,  3, this.constantPoolOffset[constantPoolEntry.getNameAndTypeIndex()]);
				constantPoolEntry.setFieldName(getUtf8ValueAt(fieldNameIndex));
				constantPoolEntry.setFieldDescriptor(getUtf8ValueAt(fieldDescriptorIndex));
				break;
			case IConstantPoolConstant.CONSTANT_Methodref :
			case IConstantPoolConstant.CONSTANT_InterfaceMethodref :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setClassIndex(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				declaringClassIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[constantPoolEntry.getClassIndex()]);
				constantPoolEntry.setClassName(getUtf8ValueAt(declaringClassIndex));
				constantPoolEntry.setNameAndTypeIndex(u2At(this.classFileBytes,  3, this.constantPoolOffset[index]));
				int methodNameIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[constantPoolEntry.getNameAndTypeIndex()]);
				int methodDescriptorIndex = u2At(this.classFileBytes,  3, this.constantPoolOffset[constantPoolEntry.getNameAndTypeIndex()]);
				constantPoolEntry.setMethodName(getUtf8ValueAt(methodNameIndex));
				constantPoolEntry.setMethodDescriptor(getUtf8ValueAt(methodDescriptorIndex));
				break;
			case IConstantPoolConstant.CONSTANT_Float :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setFloatValue(floatAt(this.classFileBytes, 1, this.constantPoolOffset[index]));
				break;
			case IConstantPoolConstant.CONSTANT_Integer :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setIntegerValue(i4At(this.classFileBytes, 1, this.constantPoolOffset[index]));
				break;
			case IConstantPoolConstant.CONSTANT_Long :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setLongValue(i8At(this.classFileBytes, 1, this.constantPoolOffset[index]));
				break;
			case IConstantPoolConstant.CONSTANT_NameAndType :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setNameAndTypeNameIndex(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				constantPoolEntry.setNameAndTypeDescriptorIndex(u2At(this.classFileBytes,  3, this.constantPoolOffset[index]));
				break;
			case IConstantPoolConstant.CONSTANT_String :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setStringIndex(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				constantPoolEntry.setStringValue(getUtf8ValueAt(constantPoolEntry.getStringIndex()));
				break;
			case IConstantPoolConstant.CONSTANT_Utf8 :
				constantPoolEntry = new ConstantPoolEntry();
				constantPoolEntry.reset();
				constantPoolEntry.setKind(kind);
				constantPoolEntry.setUtf8Length(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				constantPoolEntry.setUtf8Value(getUtf8ValueAt(index));
				break;
			case IConstantPoolConstant.CONSTANT_MethodHandle :
				ConstantPoolEntry2 constantPoolEntry2 = new ConstantPoolEntry2();
				constantPoolEntry2.reset();
				constantPoolEntry2.setKind(kind);
				constantPoolEntry2.setReferenceKind(u1At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				constantPoolEntry2.setReferenceIndex(u2At(this.classFileBytes,  2, this.constantPoolOffset[index]));
				constantPoolEntry = constantPoolEntry2;
				break;
			case IConstantPoolConstant.CONSTANT_MethodType :
				constantPoolEntry2 = new ConstantPoolEntry2();
				constantPoolEntry2.reset();
				constantPoolEntry2.setKind(kind);
				methodDescriptorIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[index]);
				constantPoolEntry2.setDescriptorIndex(methodDescriptorIndex);
				constantPoolEntry2.setMethodDescriptor(getUtf8ValueAt(methodDescriptorIndex));
				constantPoolEntry = constantPoolEntry2;
				break;
			case IConstantPoolConstant.CONSTANT_InvokeDynamic :
				constantPoolEntry2 = new ConstantPoolEntry2();
				constantPoolEntry2.reset();
				constantPoolEntry2.setKind(kind);
				constantPoolEntry2.setBootstrapMethodAttributeIndex(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				int nameAndTypeIndex = u2At(this.classFileBytes,  3, this.constantPoolOffset[index]);
				constantPoolEntry2.setNameAndTypeIndex(nameAndTypeIndex);
				methodNameIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[nameAndTypeIndex]);
				methodDescriptorIndex = u2At(this.classFileBytes,  3, this.constantPoolOffset[nameAndTypeIndex]);
				constantPoolEntry2.setMethodName(getUtf8ValueAt(methodNameIndex));
				constantPoolEntry2.setMethodDescriptor(getUtf8ValueAt(methodDescriptorIndex));
				constantPoolEntry = constantPoolEntry2;
				break;
			case IConstantPoolConstant.CONSTANT_Dynamic :
				constantPoolEntry2 = new ConstantPoolEntry2();
				constantPoolEntry2.reset();
				constantPoolEntry2.setKind(kind);
				constantPoolEntry2.setBootstrapMethodAttributeIndex(u2At(this.classFileBytes,  1, this.constantPoolOffset[index]));
				int nameAndTypeIndex2 = u2At(this.classFileBytes,  3, this.constantPoolOffset[index]);
				constantPoolEntry2.setNameAndTypeIndex(nameAndTypeIndex2);
				fieldNameIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[nameAndTypeIndex2]);
				fieldDescriptorIndex = u2At(this.classFileBytes,  3, this.constantPoolOffset[nameAndTypeIndex2]);
				constantPoolEntry2.setFieldName(getUtf8ValueAt(fieldNameIndex));
				constantPoolEntry2.setFieldDescriptor(getUtf8ValueAt(fieldDescriptorIndex));
				constantPoolEntry = constantPoolEntry2;
				break;
			case IConstantPoolConstant.CONSTANT_Module :
				constantPoolEntry2 = new ConstantPoolEntry2();
				constantPoolEntry2.reset();
				constantPoolEntry2.setKind(kind);
				int moduleIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[index]);
				constantPoolEntry2.setModuleIndex(moduleIndex);
				constantPoolEntry2.setModuleName(getUtf8ValueAt(moduleIndex));
				constantPoolEntry = constantPoolEntry2;
				break;
			case IConstantPoolConstant.CONSTANT_Package :
				constantPoolEntry2 = new ConstantPoolEntry2();
				constantPoolEntry2.reset();
				constantPoolEntry2.setKind(kind);
				int packageIndex = u2At(this.classFileBytes,  1, this.constantPoolOffset[index]);
				constantPoolEntry2.setPackageIndex(packageIndex);
				constantPoolEntry2.setPackageName(getUtf8ValueAt(packageIndex));
				constantPoolEntry = constantPoolEntry2;
				break;
		}
		return constantPoolEntry;
	}

	
See Also:
  • getConstantPoolCount.getConstantPoolCount()
/**
	 * @see IConstantPool#getConstantPoolCount()
	 */
	@Override
	public int getConstantPoolCount() {
		return this.constantPoolCount;
	}

	
See Also:
  • getEntryKind.getEntryKind(int)
/**
	 * @see IConstantPool#getEntryKind(int)
	 */
	@Override
	public int getEntryKind(int index) {
		return u1At(this.classFileBytes, 0, this.constantPoolOffset[index]);
	}

	private char[] getUtf8ValueAt(int utf8Index) {
		int utf8Offset = this.constantPoolOffset[utf8Index];
		return utf8At(this.classFileBytes, 0, utf8Offset + 3, u2At(this.classFileBytes, 0, utf8Offset + 1));
	}
}