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1   /*
2    * Copyright  2000-2004 The Apache Software Foundation
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License"); 
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License. 
15   *
16   */
17  package org.apache.bcel.generic;
18  
19  /*** 
20   * LDC2_W - Push long or double from constant pool
21   *
22   * <PRE>Stack: ... -&gt; ..., item.word1, item.word2</PRE>
23   *
24   * @version $Id: LDC2_W.java 386056 2006-03-15 11:31:56Z tcurdt $
25   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
26   */
27  public class LDC2_W extends CPInstruction implements PushInstruction, TypedInstruction {
28  
29      /***
30       * Empty constructor needed for the Class.newInstance() statement in
31       * Instruction.readInstruction(). Not to be used otherwise.
32       */
33      LDC2_W() {
34      }
35  
36  
37      public LDC2_W(int index) {
38          super(org.apache.bcel.Constants.LDC2_W, index);
39      }
40  
41  
42      public Type getType( ConstantPoolGen cpg ) {
43          switch (cpg.getConstantPool().getConstant(index).getTag()) {
44              case org.apache.bcel.Constants.CONSTANT_Long:
45                  return Type.LONG;
46              case org.apache.bcel.Constants.CONSTANT_Double:
47                  return Type.DOUBLE;
48              default: // Never reached
49                  throw new RuntimeException("Unknown constant type " + opcode);
50          }
51      }
52  
53  
54      public Number getValue( ConstantPoolGen cpg ) {
55          org.apache.bcel.classfile.Constant c = cpg.getConstantPool().getConstant(index);
56          switch (c.getTag()) {
57              case org.apache.bcel.Constants.CONSTANT_Long:
58                  return new Long(((org.apache.bcel.classfile.ConstantLong) c).getBytes());
59              case org.apache.bcel.Constants.CONSTANT_Double:
60                  return new Double(((org.apache.bcel.classfile.ConstantDouble) c).getBytes());
61              default: // Never reached
62                  throw new RuntimeException("Unknown or invalid constant type at " + index);
63          }
64      }
65  
66  
67      /***
68       * Call corresponding visitor method(s). The order is:
69       * Call visitor methods of implemented interfaces first, then
70       * call methods according to the class hierarchy in descending order,
71       * i.e., the most specific visitXXX() call comes last.
72       *
73       * @param v Visitor object
74       */
75      public void accept( Visitor v ) {
76          v.visitStackProducer(this);
77          v.visitPushInstruction(this);
78          v.visitTypedInstruction(this);
79          v.visitCPInstruction(this);
80          v.visitLDC2_W(this);
81      }
82  }