    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 class is derived from the abstract {@link Constant} and represents a reference to the name and signature of a
    027 * field or method.
    028 *
    029 * @see Constant
    030 */
    031public final class ConstantNameAndType extends Constant {
    032
    033    private int nameIndex; // Name of field/method
    034    private int signatureIndex; // and its signature.
    035
    036    /**
    037     * Initialize from another object.
    038     *
    039     * @param c Source to copy.
    040     */
    041    public ConstantNameAndType(final ConstantNameAndType c) {
    042        this(c.getNameIndex(), c.getSignatureIndex());
    043    }
    044
    045    /**
    046     * Initialize instance from file data.
    047     *
    048     * @param file Input stream
    049     * @throws IOException if an I/O error occurs.
    050     */
    051    ConstantNameAndType(final DataInput file) throws IOException {
    052        this(file.readUnsignedShort(), file.readUnsignedShort());
    053    }
    054
    055    /**
    056     * @param nameIndex Name of field/method
    057     * @param signatureIndex and its signature
    058     */
    059    public ConstantNameAndType(final int nameIndex, final int signatureIndex) {
    060        super(Const.CONSTANT_NameAndType);
    061        this.nameIndex = nameIndex;
    062        this.signatureIndex = signatureIndex;
    063    }
    064
    065    /**
    066     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
    067     * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
    068     *
    069     * @param v Visitor object
    070     */
    071    @Override
    072    public void accept(final Visitor v) {
    073        v.visitConstantNameAndType(this);
    074    }
    075
    076    /**
    077     * Dump name and signature index to file stream in binary format.
    078     *
    079     * @param file Output file stream
    080     * @throws IOException if an I/O error occurs.
    081     */
    082    @Override
    083    public void dump(final DataOutputStream file) throws IOException {
    084        file.writeByte(super.getTag());
    085        file.writeShort(nameIndex);
    086        file.writeShort(signatureIndex);
    087    }
    088
    089    /**
    090     * @return name
    091     */
    092    public String getName(final ConstantPool cp) {
    093        return cp.constantToString(getNameIndex(), Const.CONSTANT_Utf8);
    094    }
    095
    096    /**
    097     * @return Name index in constant pool of field/method name.
    098     */
    099    public int getNameIndex() {
    100        return nameIndex;
    101    }
    102
    103    /**
    104     * @return signature
    105     */
    106    public String getSignature(final ConstantPool cp) {
    107        return cp.constantToString(getSignatureIndex(), Const.CONSTANT_Utf8);
    108    }
    109
    110    /**
    111     * @return Index in constant pool of field/method signature.
    112     */
    113    public int getSignatureIndex() {
    114        return signatureIndex;
    115    }
    116
    117    /**
    118     * @param nameIndex the name index of this constant
    119     */
    120    public void setNameIndex(final int nameIndex) {
    121        this.nameIndex = nameIndex;
    122    }
    123
    124    /**
    125     * @param signatureIndex the signature index in the constant pool of this type
    126     */
    127    public void setSignatureIndex(final int signatureIndex) {
    128        this.signatureIndex = signatureIndex;
    129    }
    130
    131    /**
    132     * @return String representation
    133     */
    134    @Override
    135    public String toString() {
    136        return super.toString() + "(nameIndex = " + nameIndex + ", signatureIndex = " + signatureIndex + ")";
    137    }
    138}