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.DataOutputStream;
022import java.io.IOException;
023
024/**
025 * An annotation's element value pair.
026 *
027 * @since 6.0
028 */
029public class ElementValuePair {
030
031    static final ElementValuePair[] EMPTY_ARRAY = {};
032
033    private final ElementValue elementValue;
034
035    private final ConstantPool constantPool;
036
037    private final int elementNameIndex;
038
039    /**
040     * Constructs an ElementValuePair.
041     *
042     * @param elementNameIndex the element name index.
043     * @param elementValue the element value.
044     * @param constantPool the constant pool.
045     */
046    public ElementValuePair(final int elementNameIndex, final ElementValue elementValue, final ConstantPool constantPool) {
047        this.elementValue = elementValue;
048        this.elementNameIndex = elementNameIndex;
049        this.constantPool = constantPool;
050    }
051
052    /**
053     * Dumps this element value pair to a DataOutputStream.
054     *
055     * @param dos the output stream.
056     * @throws IOException if an I/O error occurs.
057     */
058    protected void dump(final DataOutputStream dos) throws IOException {
059        dos.writeShort(elementNameIndex); // u2 name of the element
060        elementValue.dump(dos);
061    }
062
063    /**
064     * Gets the name index.
065     *
066     * @return the name index.
067     */
068    public int getNameIndex() {
069        return elementNameIndex;
070    }
071
072    /**
073     * Gets the name string.
074     *
075     * @return the name string.
076     */
077    public String getNameString() {
078        return constantPool.getConstantUtf8(elementNameIndex).getBytes();
079    }
080
081    /**
082     * Gets the value.
083     *
084     * @return the element value.
085     */
086    public final ElementValue getValue() {
087        return elementValue;
088    }
089
090    /**
091     * Gets a short string representation.
092     *
093     * @return a short string representation.
094     */
095    public String toShortString() {
096        final StringBuilder result = new StringBuilder();
097        result.append(getNameString()).append("=").append(getValue().toShortString());
098        return result.toString();
099    }
100}