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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   https://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.bcel.classfile;
20  
21  import java.io.DataInput;
22  import java.io.DataOutputStream;
23  import java.io.IOException;
24  
25  import org.apache.bcel.Const;
26  
27  /**
28   * This class is derived from the abstract {@link Constant} and represents a reference to a method handle.
29   *
30   * @see Constant
31   * @since 6.0
32   */
33  public final class ConstantMethodHandle extends Constant {
34  
35      private int referenceKind;
36      private int referenceIndex;
37  
38      /**
39       * Initialize from another object.
40       *
41       * @param c Source to copy.
42       */
43      public ConstantMethodHandle(final ConstantMethodHandle c) {
44          this(c.getReferenceKind(), c.getReferenceIndex());
45      }
46  
47      /**
48       * Initialize instance from file data.
49       *
50       * @param file Input stream
51       * @throws IOException if an I/O error occurs.
52       */
53      ConstantMethodHandle(final DataInput file) throws IOException {
54          this(file.readUnsignedByte(), file.readUnsignedShort());
55      }
56  
57      public ConstantMethodHandle(final int referenceKind, final int referenceIndex) {
58          super(Const.CONSTANT_MethodHandle);
59          this.referenceKind = referenceKind;
60          this.referenceIndex = referenceIndex;
61      }
62  
63      /**
64       * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
65       * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
66       *
67       * @param v Visitor object
68       */
69      @Override
70      public void accept(final Visitor v) {
71          v.visitConstantMethodHandle(this);
72      }
73  
74      /**
75       * Dump method kind and index to file stream in binary format.
76       *
77       * @param file Output file stream
78       * @throws IOException if an I/O error occurs.
79       */
80      @Override
81      public void dump(final DataOutputStream file) throws IOException {
82          file.writeByte(super.getTag());
83          file.writeByte(referenceKind);
84          file.writeShort(referenceIndex);
85      }
86  
87      public int getReferenceIndex() {
88          return referenceIndex;
89      }
90  
91      public int getReferenceKind() {
92          return referenceKind;
93      }
94  
95      public void setReferenceIndex(final int referenceIndex) {
96          this.referenceIndex = referenceIndex;
97      }
98  
99      public void setReferenceKind(final int referenceKind) {
100         this.referenceKind = referenceKind;
101     }
102 
103     /**
104      * @return String representation
105      */
106     @Override
107     public String toString() {
108         return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")";
109     }
110 }