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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  import org.apache.bcel.classfile.ConstantCP;
20  import org.apache.bcel.classfile.ConstantNameAndType;
21  import org.apache.bcel.classfile.ConstantPool;
22  import org.apache.bcel.classfile.ConstantUtf8;
23  
24  /***
25   * Super class for InvokeInstruction and FieldInstruction, since they have
26   * some methods in common!
27   *
28   * @version $Id: FieldOrMethod.java 386056 2006-03-15 11:31:56Z tcurdt $
29   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
30   */
31  public abstract class FieldOrMethod extends CPInstruction implements LoadClass {
32  
33      /***
34       * Empty constructor needed for the Class.newInstance() statement in
35       * Instruction.readInstruction(). Not to be used otherwise.
36       */
37      FieldOrMethod() {
38      }
39  
40  
41      /***
42       * @param index to constant pool
43       */
44      protected FieldOrMethod(short opcode, int index) {
45          super(opcode, index);
46      }
47  
48  
49      /*** @return signature of referenced method/field.
50       */
51      public String getSignature( ConstantPoolGen cpg ) {
52          ConstantPool cp = cpg.getConstantPool();
53          ConstantCP cmr = (ConstantCP) cp.getConstant(index);
54          ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
55          return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();
56      }
57  
58  
59      /*** @return name of referenced method/field.
60       */
61      public String getName( ConstantPoolGen cpg ) {
62          ConstantPool cp = cpg.getConstantPool();
63          ConstantCP cmr = (ConstantCP) cp.getConstant(index);
64          ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
65          return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();
66      }
67  
68  
69      /*** @return name of the referenced class/interface
70       *  @deprecated If the instruction references an array class,
71       *    this method will return "java.lang.Object".
72       *    For code generated by Java 1.5, this answer is
73       *    sometimes wrong (e.g., if the "clone()" method is
74       *    called on an array).  A better idea is to use
75       *    the getReferenceType() method, which correctly distinguishes
76       *    between class types and array types.
77       */
78      public String getClassName( ConstantPoolGen cpg ) {
79          ConstantPool cp = cpg.getConstantPool();
80          ConstantCP cmr = (ConstantCP) cp.getConstant(index);
81          String className = cp.getConstantString(cmr.getClassIndex(),
82                  org.apache.bcel.Constants.CONSTANT_Class);
83          if (className.startsWith("[")) {
84              // Turn array classes into java.lang.Object.
85              return "java.lang.Object";
86          }
87          return className.replace('/', '.');
88      }
89  
90  
91      /*** @return type of the referenced class/interface
92       * @deprecated If the instruction references an array class,
93       *    the ObjectType returned will be invalid.  Use
94       *    getReferenceType() instead.
95       */
96      public ObjectType getClassType( ConstantPoolGen cpg ) {
97          return new ObjectType(getClassName(cpg));
98      }
99  
100 
101     /***
102      * Return the reference type representing the class, interface,
103      * or array class referenced by the instruction.
104      * @param cpg the ConstantPoolGen used to create the instruction
105      * @return an ObjectType (if the referenced class type is a class
106      *   or interface), or an ArrayType (if the referenced class
107      *   type is an array class)
108      */
109     public ReferenceType getReferenceType( ConstantPoolGen cpg ) {
110         ConstantPool cp = cpg.getConstantPool();
111         ConstantCP cmr = (ConstantCP) cp.getConstant(index);
112         String className = cp.getConstantString(cmr.getClassIndex(),
113                 org.apache.bcel.Constants.CONSTANT_Class);
114         if (className.startsWith("[")) {
115             return (ArrayType) Type.getType(className);
116         } else {
117             className = className.replace('/', '.');
118             return new ObjectType(className);
119         }
120     }
121 
122 
123     /*** @return type of the referenced class/interface
124      */
125     public ObjectType getLoadClassType( ConstantPoolGen cpg ) {
126         return getClassType(cpg);
127     }
128 }