    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 *   https://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019package org.apache.bcel.classfile;
    020
    021import java.io.DataInput;
    022import java.io.DataOutputStream;
    023import java.io.IOException;
    024
    025import org.apache.bcel.Const;
    026
    027/**
    028 * This class is derived from the abstract {@link Constant} and represents a reference to the name and signature of a
    029 * field or method.
    030 *
    031 * @see Constant
    032 */
    033public final class ConstantNameAndType extends Constant {
    034
    035    private int nameIndex; // Name of field/method
    036    private int signatureIndex; // and its signature.
    037
    038    /**
    039     * Initialize from another object.
    040     *
    041     * @param c Source to copy.
    042     */
    043    public ConstantNameAndType(final ConstantNameAndType c) {
    044        this(c.getNameIndex(), c.getSignatureIndex());
    045    }
    046
    047    /**
    048     * Initialize instance from file data.
    049     *
    050     * @param file Input stream
    051     * @throws IOException if an I/O error occurs.
    052     */
    053    ConstantNameAndType(final DataInput file) throws IOException {
    054        this(file.readUnsignedShort(), file.readUnsignedShort());
    055    }
    056
    057    /**
    058     * @param nameIndex Name of field/method
    059     * @param signatureIndex and its signature
    060     */
    061    public ConstantNameAndType(final int nameIndex, final int signatureIndex) {
    062        super(Const.CONSTANT_NameAndType);
    063        this.nameIndex = nameIndex;
    064        this.signatureIndex = signatureIndex;
    065    }
    066
    067    /**
    068     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
    069     * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
    070     *
    071     * @param v Visitor object
    072     */
    073    @Override
    074    public void accept(final Visitor v) {
    075        v.visitConstantNameAndType(this);
    076    }
    077
    078    /**
    079     * Dump name and signature index to file stream in binary format.
    080     *
    081     * @param file Output file stream
    082     * @throws IOException if an I/O error occurs.
    083     */
    084    @Override
    085    public void dump(final DataOutputStream file) throws IOException {
    086        file.writeByte(super.getTag());
    087        file.writeShort(nameIndex);
    088        file.writeShort(signatureIndex);
    089    }
    090
    091    /**
    092     * @return name
    093     */
    094    public String getName(final ConstantPool cp) {
    095        return cp.constantToString(getNameIndex(), Const.CONSTANT_Utf8);
    096    }
    097
    098    /**
    099     * @return Name index in constant pool of field/method name.
    100     */
    101    public int getNameIndex() {
    102        return nameIndex;
    103    }
    104
    105    /**
    106     * @return signature
    107     */
    108    public String getSignature(final ConstantPool cp) {
    109        return cp.constantToString(getSignatureIndex(), Const.CONSTANT_Utf8);
    110    }
    111
    112    /**
    113     * @return Index in constant pool of field/method signature.
    114     */
    115    public int getSignatureIndex() {
    116        return signatureIndex;
    117    }
    118
    119    /**
    120     * @param nameIndex the name index of this constant
    121     */
    122    public void setNameIndex(final int nameIndex) {
    123        this.nameIndex = nameIndex;
    124    }
    125
    126    /**
    127     * @param signatureIndex the signature index in the constant pool of this type
    128     */
    129    public void setSignatureIndex(final int signatureIndex) {
    130        this.signatureIndex = signatureIndex;
    131    }
    132
    133    /**
    134     * @return String representation
    135     */
    136    @Override
    137    public String toString() {
    138        return super.toString() + "(nameIndex = " + nameIndex + ", signatureIndex = " + signatureIndex + ")";
    139    }
    140}