    001/**
    002 *  Licensed to the Apache Software Foundation (ASF) under one or more
    003 *  contributor license agreements.  See the NOTICE file distributed with
    004 *  this work for additional information regarding copyright ownership.
    005 *  The ASF licenses this file to You under the Apache License, Version 2.0
    006 *  (the "License"); you may not use this file except in compliance with
    007 *  the License.  You may obtain a copy of the License at
    008 *
    009 *     http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 */
    017package org.apache.bcel.classfile;
    018
    019import java.io.DataInput;
    020import java.io.DataOutputStream;
    021import java.io.IOException;
    022
    023import org.apache.bcel.Const;
    024
    025/**
    026 * This attribute exists for local or
    027 * anonymous classes and ... there can be only one.
    028 *
    029 * @since 6.0
    030 */
    031public class EnclosingMethod extends Attribute {
    032
    033    // Pointer to the CONSTANT_Class_info structure representing the
    034    // innermost class that encloses the declaration of the current class.
    035    private int classIndex;
    036
    037    // If the current class is not immediately enclosed by a method or
    038    // constructor, then the value of the method_index item must be zero.
    039    // Otherwise, the value of the  method_index item must point to a
    040    // CONSTANT_NameAndType_info structure representing the name and the
    041    // type of a method in the class referenced by the class we point
    042    // to in the class_index.  *It is the compiler responsibility* to
    043    // ensure that the method identified by this index is the closest
    044    // lexically enclosing method that includes the local/anonymous class.
    045    private int methodIndex;
    046
    047    // Ctors - and code to read an attribute in.
    048    EnclosingMethod(final int nameIndex, final int len, final DataInput input, final ConstantPool cpool) throws IOException {
    049        this(nameIndex, len, input.readUnsignedShort(), input.readUnsignedShort(), cpool);
    050    }
    051
    052    private EnclosingMethod(final int nameIndex, final int len, final int classIdx,final int methodIdx, final ConstantPool cpool) {
    053        super(Const.ATTR_ENCLOSING_METHOD, nameIndex, len, cpool);
    054        classIndex  = classIdx;
    055        methodIndex = methodIdx;
    056    }
    057
    058    @Override
    059    public void accept(final Visitor v) {
    060      v.visitEnclosingMethod(this);
    061    }
    062
    063    @Override
    064    public Attribute copy(final ConstantPool constant_pool) {
    065        return (Attribute) clone();
    066    }
    067
    068    // Accessors
    069    public final int getEnclosingClassIndex() {
    070        return classIndex;
    071    }
    072
    073    public final int getEnclosingMethodIndex() {
    074        return methodIndex;
    075    }
    076
    077    public final void setEnclosingClassIndex(final int idx) {
    078        classIndex = idx;
    079    }
    080
    081    public final void setEnclosingMethodIndex(final int idx) {
    082        methodIndex = idx;
    083    }
    084
    085    public final ConstantClass getEnclosingClass() {
    086        final ConstantClass c =
    087            (ConstantClass)super.getConstantPool().getConstant(classIndex,Const.CONSTANT_Class);
    088        return c;
    089    }
    090
    091    public final ConstantNameAndType getEnclosingMethod() {
    092        if (methodIndex == 0) {
    093            return null;
    094        }
    095        final ConstantNameAndType nat =
    096            (ConstantNameAndType)super.getConstantPool().getConstant(methodIndex,Const.CONSTANT_NameAndType);
    097        return nat;
    098    }
    099
    100    @Override
    101    public final void dump(final DataOutputStream file) throws IOException {
    102        super.dump(file);
    103        file.writeShort(classIndex);
    104        file.writeShort(methodIndex);
    105    }
    106}