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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  package org.apache.bcel.generic;
18  
19  /**
20   * DCONST - Push 0.0 or 1.0, other values cause an exception
21   *
22   * <PRE>
23   * Stack: ... -&gt; ...,
24   * </PRE>
25   */
26  public class DCONST extends Instruction implements ConstantPushInstruction {
27  
28      private final double value;
29  
30      /**
31       * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
32       */
33      DCONST() {
34          this(0);
35      }
36  
37      public DCONST(final double f) {
38          super(org.apache.bcel.Const.DCONST_0, (short) 1);
39          if (f == 0.0) {
40              super.setOpcode(org.apache.bcel.Const.DCONST_0);
41          } else if (f == 1.0) {
42              super.setOpcode(org.apache.bcel.Const.DCONST_1);
43          } else {
44              throw new ClassGenException("DCONST can be used only for 0.0 and 1.0: " + f);
45          }
46          value = f;
47      }
48  
49      /**
50       * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
51       * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
52       *
53       * @param v Visitor object
54       */
55      @Override
56      public void accept(final Visitor v) {
57          v.visitPushInstruction(this);
58          v.visitStackProducer(this);
59          v.visitTypedInstruction(this);
60          v.visitConstantPushInstruction(this);
61          v.visitDCONST(this);
62      }
63  
64      /**
65       * @return Type.DOUBLE
66       */
67      @Override
68      public Type getType(final ConstantPoolGen cp) {
69          return Type.DOUBLE;
70      }
71  
72      @Override
73      public Number getValue() {
74          return Double.valueOf(value);
75      }
76  }