    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 anonymous classes and ... there can be only one.
    027 *
    028 * @since 6.0
    029 */
    030public class EnclosingMethod extends Attribute {
    031
    032    // Pointer to the CONSTANT_Class_info structure representing the
    033    // innermost class that encloses the declaration of the current class.
    034    private int classIndex;
    035
    036    // If the current class is not immediately enclosed by a method or
    037    // constructor, then the value of the method_index item must be zero.
    038    // Otherwise, the value of the method_index item must point to a
    039    // CONSTANT_NameAndType_info structure representing the name and the
    040    // type of a method in the class referenced by the class we point
    041    // to in the class_index. *It is the compiler responsibility* to
    042    // ensure that the method identified by this index is the closest
    043    // lexically enclosing method that includes the local/anonymous class.
    044    private int methodIndex;
    045
    046    // Ctors - and code to read an attribute in.
    047    EnclosingMethod(final int nameIndex, final int len, final DataInput input, final ConstantPool cpool) throws IOException {
    048        this(nameIndex, len, input.readUnsignedShort(), input.readUnsignedShort(), cpool);
    049    }
    050
    051    private EnclosingMethod(final int nameIndex, final int len, final int classIdx, final int methodIdx, final ConstantPool cpool) {
    052        super(Const.ATTR_ENCLOSING_METHOD, nameIndex, len, cpool);
    053        classIndex = classIdx;
    054        methodIndex = methodIdx;
    055    }
    056
    057    @Override
    058    public void accept(final Visitor v) {
    059        v.visitEnclosingMethod(this);
    060    }
    061
    062    @Override
    063    public Attribute copy(final ConstantPool constant_pool) {
    064        return (Attribute) clone();
    065    }
    066
    067    @Override
    068    public final void dump(final DataOutputStream file) throws IOException {
    069        super.dump(file);
    070        file.writeShort(classIndex);
    071        file.writeShort(methodIndex);
    072    }
    073
    074    public final ConstantClass getEnclosingClass() {
    075        return super.getConstantPool().getConstant(classIndex, Const.CONSTANT_Class, ConstantClass.class);
    076    }
    077
    078    // Accessors
    079    public final int getEnclosingClassIndex() {
    080        return classIndex;
    081    }
    082
    083    public final ConstantNameAndType getEnclosingMethod() {
    084        if (methodIndex == 0) {
    085            return null;
    086        }
    087        return super.getConstantPool().getConstant(methodIndex, Const.CONSTANT_NameAndType, ConstantNameAndType.class);
    088    }
    089
    090    public final int getEnclosingMethodIndex() {
    091        return methodIndex;
    092    }
    093
    094    public final void setEnclosingClassIndex(final int idx) {
    095        classIndex = idx;
    096    }
    097
    098    public final void setEnclosingMethodIndex(final int idx) {
    099        methodIndex = idx;
    100    }
    101}