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 * 017 */ 018package org.apache.bcel.classfile; 019 020import java.io.DataInput; 021import java.io.DataOutputStream; 022import java.io.IOException; 023 024import org.apache.bcel.Const; 025 026/** 027 * This class is derived from the abstract {@link Constant} and represents a reference to a method handle. 028 * 029 * @see Constant 030 * @since 6.0 031 */ 032public final class ConstantMethodHandle extends Constant { 033 034 private int referenceKind; 035 private int referenceIndex; 036 037 /** 038 * Initialize from another object. 039 */ 040 public ConstantMethodHandle(final ConstantMethodHandle c) { 041 this(c.getReferenceKind(), c.getReferenceIndex()); 042 } 043 044 /** 045 * Initialize instance from file data. 046 * 047 * @param file Input stream 048 * @throws IOException if an I/O error occurs. 049 */ 050 ConstantMethodHandle(final DataInput file) throws IOException { 051 this(file.readUnsignedByte(), file.readUnsignedShort()); 052 } 053 054 public ConstantMethodHandle(final int reference_kind, final int reference_index) { 055 super(Const.CONSTANT_MethodHandle); 056 this.referenceKind = reference_kind; 057 this.referenceIndex = reference_index; 058 } 059 060 /** 061 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e., 062 * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects. 063 * 064 * @param v Visitor object 065 */ 066 @Override 067 public void accept(final Visitor v) { 068 v.visitConstantMethodHandle(this); 069 } 070 071 /** 072 * Dump method kind and index to file stream in binary format. 073 * 074 * @param file Output file stream 075 * @throws IOException if an I/O error occurs. 076 */ 077 @Override 078 public void dump(final DataOutputStream file) throws IOException { 079 file.writeByte(super.getTag()); 080 file.writeByte(referenceKind); 081 file.writeShort(referenceIndex); 082 } 083 084 public int getReferenceIndex() { 085 return referenceIndex; 086 } 087 088 public int getReferenceKind() { 089 return referenceKind; 090 } 091 092 public void setReferenceIndex(final int reference_index) { 093 this.referenceIndex = reference_index; 094 } 095 096 public void setReferenceKind(final int reference_kind) { 097 this.referenceKind = reference_kind; 098 } 099 100 /** 101 * @return String representation 102 */ 103 @Override 104 public String toString() { 105 return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")"; 106 } 107}