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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   */
18  package org.apache.bcel.classfile;
19  
20  import java.io.DataInput;
21  import java.io.DataOutputStream;
22  import java.io.IOException;
23  
24  import org.apache.bcel.Const;
25  
26  /**
27   * This class is derived from the abstract {@link Constant}
28   * 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 reference_kind;
36      private int reference_index;
37  
38  
39      /**
40       * Initialize from another object.
41       */
42      public ConstantMethodHandle(final ConstantMethodHandle c) {
43          this(c.getReferenceKind(), c.getReferenceIndex());
44      }
45  
46  
47      /**
48       * Initialize instance from file data.
49       *
50       * @param file Input stream
51       * @throws IOException
52       */
53      ConstantMethodHandle(final DataInput file) throws IOException {
54          this(file.readUnsignedByte(), file.readUnsignedShort());
55      }
56  
57  
58      public ConstantMethodHandle(final int reference_kind, final int reference_index) {
59          super(Const.CONSTANT_MethodHandle);
60          this.reference_kind = reference_kind;
61          this.reference_index = reference_index;
62      }
63  
64  
65      /**
66       * Called by objects that are traversing the nodes of the tree implicitly
67       * defined by the contents of a Java class. I.e., the hierarchy of methods,
68       * fields, attributes, etc. spawns a tree of objects.
69       *
70       * @param v Visitor object
71       */
72      @Override
73      public void accept( final Visitor v ) {
74          v.visitConstantMethodHandle(this);
75      }
76  
77  
78      /**
79       * Dump method kind and index to file stream in binary format.
80       *
81       * @param file Output file stream
82       * @throws IOException
83       */
84      @Override
85      public final void dump( final DataOutputStream file ) throws IOException {
86          file.writeByte(super.getTag());
87          file.writeByte(reference_kind);
88          file.writeShort(reference_index);
89      }
90  
91  
92      public int getReferenceKind() {
93          return reference_kind;
94      }
95  
96  
97      public void setReferenceKind(final int reference_kind) {
98          this.reference_kind = reference_kind;
99      }
100 
101 
102     public int getReferenceIndex() {
103         return reference_index;
104     }
105 
106 
107     public void setReferenceIndex(final int reference_index) {
108         this.reference_index = reference_index;
109     }
110 
111 
112     /**
113      * @return String representation
114      */
115     @Override
116     public final String toString() {
117         return super.toString() + "(reference_kind = " + reference_kind +
118                 ", reference_index = " + reference_index + ")";
119     }
120 }