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Java > Open Source Codes > org > apache > bcel > generic > INSTANCEOF


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  * INSTANCEOF - Determine if object is of given type
21  * <PRE>Stack: ..., objectref -&gt; ..., result</PRE>
22  *
23  * @version $Id: INSTANCEOF.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 INSTANCEOF extends CPInstruction implements LoadClass, ExceptionThrower,
27         StackProducer, StackConsumer {
28
29     /**
30      * Empty constructor needed for the Class.newInstance() statement in
31      * Instruction.readInstruction(). Not to be used otherwise.
32      */
33     INSTANCEOF() {
34     }
35
36
37     public INSTANCEOF(int index) {
38         super(org.apache.bcel.Constants.INSTANCEOF, index);
39     }
40
41
42     public Class JavaDoc[] getExceptions() {
43         return org.apache.bcel.ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION;
44     }
45
46
47     public ObjectType getLoadClassType( ConstantPoolGen cpg ) {
48         Type t = getType(cpg);
49         if (t instanceof ArrayType) {
50             t = ((ArrayType) t).getBasicType();
51         }
52         return (t instanceof ObjectType) ? (ObjectType) t : null;
53     }
54
55
56     /**
57      * Call corresponding visitor method(s). The order is:
58      * Call visitor methods of implemented interfaces first, then
59      * call methods according to the class hierarchy in descending order,
60      * i.e., the most specific visitXXX() call comes last.
61      *
62      * @param v Visitor object
63      */
64     public void accept( Visitor v ) {
65         v.visitLoadClass(this);
66         v.visitExceptionThrower(this);
67         v.visitStackProducer(this);
68         v.visitStackConsumer(this);
69         v.visitTypedInstruction(this);
70         v.visitCPInstruction(this);
71         v.visitINSTANCEOF(this);
72     }
73 }
74
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