001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.bcel.classfile; 018 019import java.io.DataInput; 020import java.io.DataOutputStream; 021import java.io.IOException; 022 023import org.apache.bcel.Const; 024 025/** 026 * This class is derived from the abstract {@link Constant} and represents a reference to a method handle. 027 * 028 * @see Constant 029 * @since 6.0 030 */ 031public final class ConstantMethodHandle extends Constant { 032 033 private int referenceKind; 034 private int referenceIndex; 035 036 /** 037 * Initialize from another object. 038 */ 039 public ConstantMethodHandle(final ConstantMethodHandle c) { 040 this(c.getReferenceKind(), c.getReferenceIndex()); 041 } 042 043 /** 044 * Initialize instance from file data. 045 * 046 * @param file Input stream 047 * @throws IOException if an I/O error occurs. 048 */ 049 ConstantMethodHandle(final DataInput file) throws IOException { 050 this(file.readUnsignedByte(), file.readUnsignedShort()); 051 } 052 053 public ConstantMethodHandle(final int referenceKind, final int referenceIndex) { 054 super(Const.CONSTANT_MethodHandle); 055 this.referenceKind = referenceKind; 056 this.referenceIndex = referenceIndex; 057 } 058 059 /** 060 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e., 061 * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects. 062 * 063 * @param v Visitor object 064 */ 065 @Override 066 public void accept(final Visitor v) { 067 v.visitConstantMethodHandle(this); 068 } 069 070 /** 071 * Dump method kind and index to file stream in binary format. 072 * 073 * @param file Output file stream 074 * @throws IOException if an I/O error occurs. 075 */ 076 @Override 077 public void dump(final DataOutputStream file) throws IOException { 078 file.writeByte(super.getTag()); 079 file.writeByte(referenceKind); 080 file.writeShort(referenceIndex); 081 } 082 083 public int getReferenceIndex() { 084 return referenceIndex; 085 } 086 087 public int getReferenceKind() { 088 return referenceKind; 089 } 090 091 public void setReferenceIndex(final int referenceIndex) { 092 this.referenceIndex = referenceIndex; 093 } 094 095 public void setReferenceKind(final int referenceKind) { 096 this.referenceKind = referenceKind; 097 } 098 099 /** 100 * @return String representation 101 */ 102 @Override 103 public String toString() { 104 return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")"; 105 } 106}