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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   */
17  package org.apache.bcel.classfile;
18  
19  import java.io.DataInput;
20  import java.io.DataOutputStream;
21  import java.io.IOException;
22  
23  import org.apache.bcel.Const;
24  
25  /**
26   * This class is derived from the abstract {@link Constant} and represents a reference to a method handle.
27   *
28   * @see Constant
29   * @since 6.0
30   */
31  public final class ConstantMethodHandle extends Constant {
32  
33      private int referenceKind;
34      private int referenceIndex;
35  
36      /**
37       * Initialize from another object.
38       *
39       * @param c Source to copy.
40       */
41      public ConstantMethodHandle(final ConstantMethodHandle c) {
42          this(c.getReferenceKind(), c.getReferenceIndex());
43      }
44  
45      /**
46       * Initialize instance from file data.
47       *
48       * @param file Input stream
49       * @throws IOException if an I/O error occurs.
50       */
51      ConstantMethodHandle(final DataInput file) throws IOException {
52          this(file.readUnsignedByte(), file.readUnsignedShort());
53      }
54  
55      public ConstantMethodHandle(final int referenceKind, final int referenceIndex) {
56          super(Const.CONSTANT_MethodHandle);
57          this.referenceKind = referenceKind;
58          this.referenceIndex = referenceIndex;
59      }
60  
61      /**
62       * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
63       * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
64       *
65       * @param v Visitor object
66       */
67      @Override
68      public void accept(final Visitor v) {
69          v.visitConstantMethodHandle(this);
70      }
71  
72      /**
73       * Dump method kind and index to file stream in binary format.
74       *
75       * @param file Output file stream
76       * @throws IOException if an I/O error occurs.
77       */
78      @Override
79      public void dump(final DataOutputStream file) throws IOException {
80          file.writeByte(super.getTag());
81          file.writeByte(referenceKind);
82          file.writeShort(referenceIndex);
83      }
84  
85      public int getReferenceIndex() {
86          return referenceIndex;
87      }
88  
89      public int getReferenceKind() {
90          return referenceKind;
91      }
92  
93      public void setReferenceIndex(final int referenceIndex) {
94          this.referenceIndex = referenceIndex;
95      }
96  
97      public void setReferenceKind(final int referenceKind) {
98          this.referenceKind = referenceKind;
99      }
100 
101     /**
102      * @return String representation
103      */
104     @Override
105     public String toString() {
106         return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")";
107     }
108 }