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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.IOException;
22  
23  import org.apache.bcel.Const;
24  
25  /**
26   * This class is derived from the abstract {@link Constant}
27   * and represents a reference to a invoke dynamic.
28   *
29   * @see     Constant
30   * @see  <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.4.10">
31   * The CONSTANT_InvokeDynamic_info Structure in The Java Virtual Machine Specification</a>
32   * @since 6.0
33   */
34  public final class ConstantInvokeDynamic extends ConstantCP {
35  
36      /**
37       * Initialize from another object.
38       */
39      public ConstantInvokeDynamic(final ConstantInvokeDynamic c) {
40          this(c.getBootstrapMethodAttrIndex(), c.getNameAndTypeIndex());
41      }
42  
43  
44      /**
45       * Initialize instance from file data.
46       *
47       * @param file Input stream
48       * @throws IOException
49       */
50      ConstantInvokeDynamic(final DataInput file) throws IOException {
51          this(file.readShort(), file.readShort());
52      }
53  
54  
55      public ConstantInvokeDynamic(final int bootstrap_method_attr_index, final int name_and_type_index) {
56          super(Const.CONSTANT_InvokeDynamic, bootstrap_method_attr_index, name_and_type_index);
57      }
58  
59  
60      /**
61       * Called by objects that are traversing the nodes of the tree implicitly
62       * defined by the contents of a Java class. I.e., the hierarchy of methods,
63       * 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.visitConstantInvokeDynamic(this);
70      }
71  
72      /**
73       * @return Reference (index) to bootstrap method this constant refers to.
74       *
75       * Note that this method is a functional duplicate of getClassIndex
76       * for use by ConstantInvokeDynamic.
77       * @since 6.0
78       */
79      public final int getBootstrapMethodAttrIndex() {
80          return super.getClassIndex();  // AKA bootstrap_method_attr_index
81      }
82  
83      /**
84       * @return String representation
85       */
86      @Override
87      public final String toString() {
88          return super.toString().replace("class_index", "bootstrap_method_attr_index");
89      }
90  }