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.classfile;
18 
19 import java.io.DataInput;
20 import java.io.DataOutputStream;
21 import java.io.IOException;
22 
23 import org.apache.bcel.Const;
24 
25 /**
26  * This attribute exists for local or
27  * anonymous classes and ... there can be only one.
28  *
29  * @since 6.0
30  */
31 public class EnclosingMethod extends Attribute {
32 
33     // Pointer to the CONSTANT_Class_info structure representing the
34     // innermost class that encloses the declaration of the current class.
35     private int classIndex;
36 
37     // If the current class is not immediately enclosed by a method or
38     // constructor, then the value of the method_index item must be zero.
39     // Otherwise, the value of the  method_index item must point to a
40     // CONSTANT_NameAndType_info structure representing the name and the
41     // type of a method in the class referenced by the class we point
42     // to in the class_index.  *It is the compiler responsibility* to
43     // ensure that the method identified by this index is the closest
44     // lexically enclosing method that includes the local/anonymous class.
45     private int methodIndex;
46 
47     // Ctors - and code to read an attribute in.
EnclosingMethod(final int nameIndex, final int len, final DataInput input, final ConstantPool cpool)48     EnclosingMethod(final int nameIndex, final int len, final DataInput input, final ConstantPool cpool) throws IOException {
49         this(nameIndex, len, input.readUnsignedShort(), input.readUnsignedShort(), cpool);
50     }
51 
EnclosingMethod(final int nameIndex, final int len, final int classIdx,final int methodIdx, final ConstantPool cpool)52     private EnclosingMethod(final int nameIndex, final int len, final int classIdx,final int methodIdx, final ConstantPool cpool) {
53         super(Const.ATTR_ENCLOSING_METHOD, nameIndex, len, cpool);
54         classIndex  = classIdx;
55         methodIndex = methodIdx;
56     }
57 
58     @Override
accept(final Visitor v)59     public void accept(final Visitor v) {
60       v.visitEnclosingMethod(this);
61     }
62 
63     @Override
copy(final ConstantPool constant_pool)64     public Attribute copy(final ConstantPool constant_pool) {
65         return (Attribute) clone();
66     }
67 
68     // Accessors
getEnclosingClassIndex()69     public final int getEnclosingClassIndex() {
70         return classIndex;
71     }
72 
getEnclosingMethodIndex()73     public final int getEnclosingMethodIndex() {
74         return methodIndex;
75     }
76 
setEnclosingClassIndex(final int idx)77     public final void setEnclosingClassIndex(final int idx) {
78         classIndex = idx;
79     }
80 
setEnclosingMethodIndex(final int idx)81     public final void setEnclosingMethodIndex(final int idx) {
82         methodIndex = idx;
83     }
84 
getEnclosingClass()85     public final ConstantClass getEnclosingClass() {
86         final ConstantClass c =
87             (ConstantClass)super.getConstantPool().getConstant(classIndex,Const.CONSTANT_Class);
88         return c;
89     }
90 
getEnclosingMethod()91     public final ConstantNameAndType getEnclosingMethod() {
92         if (methodIndex == 0) {
93             return null;
94         }
95         final ConstantNameAndType nat =
96             (ConstantNameAndType)super.getConstantPool().getConstant(methodIndex,Const.CONSTANT_NameAndType);
97         return nat;
98     }
99 
100     @Override
dump(final DataOutputStream file)101     public final void dump(final DataOutputStream file) throws IOException {
102         super.dump(file);
103         file.writeShort(classIndex);
104         file.writeShort(methodIndex);
105     }
106 }
107