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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 }
     91