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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 represents a BootstrapMethods attribute.
28   *
29   * @see <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.23">
30   * The class File Format : The BootstrapMethods Attribute</a>
31   * @since 6.0
32   */
33  public class BootstrapMethods extends Attribute {
34  
35      private BootstrapMethod[] bootstrap_methods;  // TODO this could be made final (setter is not used)
36  
37      /**
38       * Initialize from another object. Note that both objects use the same
39       * references (shallow copy). Use clone() for a physical copy.
40       */
41      public BootstrapMethods(final BootstrapMethods c) {
42          this(c.getNameIndex(), c.getLength(), c.getBootstrapMethods(), c.getConstantPool());
43      }
44  
45  
46      /**
47       * @param name_index Index in constant pool to CONSTANT_Utf8
48       * @param length Content length in bytes
49       * @param bootstrap_methods array of bootstrap methods
50       * @param constant_pool Array of constants
51       */
52      public BootstrapMethods(final int name_index, final int length, final BootstrapMethod[] bootstrap_methods, final ConstantPool constant_pool) {
53          super(Const.ATTR_BOOTSTRAP_METHODS, name_index, length, constant_pool);
54          this.bootstrap_methods = bootstrap_methods;
55      }
56  
57      /**
58       * Construct object from Input stream.
59       *
60       * @param name_index Index in constant pool to CONSTANT_Utf8
61       * @param length Content length in bytes
62       * @param input Input stream
63       * @param constant_pool Array of constants
64       * @throws IOException
65       */
66      BootstrapMethods(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException {
67          this(name_index, length, (BootstrapMethod[]) null, constant_pool);
68  
69          final int num_bootstrap_methods = input.readUnsignedShort();
70          bootstrap_methods = new BootstrapMethod[num_bootstrap_methods];
71          for (int i = 0; i < num_bootstrap_methods; i++) {
72              bootstrap_methods[i] = new BootstrapMethod(input);
73          }
74      }
75  
76      /**
77       * @return array of bootstrap method "records"
78       */
79      public final BootstrapMethod[] getBootstrapMethods() {
80          return bootstrap_methods;
81      }
82  
83      /**
84       * @param bootstrap_methods the array of bootstrap methods
85       */
86      public final void setBootstrapMethods(final BootstrapMethod[] bootstrap_methods) {
87          this.bootstrap_methods = bootstrap_methods;
88      }
89  
90      /**
91       * @param v Visitor object
92       */
93      @Override
94      public void accept(final Visitor v) {
95          v.visitBootstrapMethods(this);
96      }
97  
98      /**
99       * @return deep copy of this attribute
100      */
101     @Override
102     public BootstrapMethods copy(final ConstantPool _constant_pool) {
103         final BootstrapMethods c = (BootstrapMethods) clone();
104         c.bootstrap_methods = new BootstrapMethod[bootstrap_methods.length];
105 
106         for (int i = 0; i < bootstrap_methods.length; i++) {
107             c.bootstrap_methods[i] = bootstrap_methods[i].copy();
108         }
109         c.setConstantPool(_constant_pool);
110         return c;
111     }
112 
113     /**
114      * Dump bootstrap methods attribute to file stream in binary format.
115      *
116      * @param file Output file stream
117      * @throws IOException
118      */
119     @Override
120     public final void dump(final DataOutputStream file) throws IOException {
121         super.dump(file);
122 
123         file.writeShort(bootstrap_methods.length);
124         for (final BootstrapMethod bootstrap_method : bootstrap_methods) {
125             bootstrap_method.dump(file);
126         }
127     }
128 
129     /**
130      * @return String representation.
131      */
132     @Override
133     public final String toString() {
134         final StringBuilder buf = new StringBuilder();
135         buf.append("BootstrapMethods(");
136         buf.append(bootstrap_methods.length);
137         buf.append("):\n");
138         for (int i = 0; i < bootstrap_methods.length; i++) {
139             buf.append("  ").append(i).append(": ");
140             buf.append(bootstrap_methods[i].toString(super.getConstantPool())).append("\n");
141         }
142         return buf.toString();
143     }
144 }