View Javadoc

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   * ACONST_NULL - Push null reference
21   * <PRE>Stack: ... -&gt; ..., null</PRE>
22   *
23   * @version $Id: ACONST_NULL.java 386056 2006-03-15 11:31:56Z tcurdt $
24   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
25   */
26  public class ACONST_NULL extends Instruction implements PushInstruction, TypedInstruction {
27  
28      /*** 
29       * Push null reference
30       */
31      public ACONST_NULL() {
32          super(org.apache.bcel.Constants.ACONST_NULL, (short) 1);
33      }
34  
35  
36      /*** @return Type.NULL
37       */
38      public Type getType( ConstantPoolGen cp ) {
39          return Type.NULL;
40      }
41  
42  
43      /***
44       * Call corresponding visitor method(s). The order is:
45       * Call visitor methods of implemented interfaces first, then
46       * call methods according to the class hierarchy in descending order,
47       * i.e., the most specific visitXXX() call comes last.
48       *
49       * @param v Visitor object
50       */
51      public void accept( Visitor v ) {
52          v.visitStackProducer(this);
53          v.visitPushInstruction(this);
54          v.visitTypedInstruction(this);
55          v.visitACONST_NULL(this);
56      }
57  }