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 */
017
018package org.apache.bcel.classfile;
019
020import java.io.DataInput;
021import java.io.DataOutputStream;
022import java.io.IOException;
023
024import org.apache.bcel.Const;
025
026/**
027 * Entry of the parameters table.
028 *
029 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.24"> The class File Format :
030 *      The MethodParameters Attribute</a>
031 * @since 6.0
032 */
033public class MethodParameter implements Cloneable, Node {
034
035    /** Index of the CONSTANT_Utf8_info structure in the constant_pool table representing the name of the parameter */
036    private int nameIndex;
037
038    /** The access flags */
039    private int accessFlags;
040
041    public MethodParameter() {
042    }
043
044    /**
045     * Construct object from input stream.
046     *
047     * @param input Input stream
048     * @throws IOException if an I/O error occurs.
049     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
050     */
051    MethodParameter(final DataInput input) throws IOException {
052        nameIndex = input.readUnsignedShort();
053        accessFlags = input.readUnsignedShort();
054    }
055
056    @Override
057    public void accept(final Visitor v) {
058        v.visitMethodParameter(this);
059    }
060
061    /**
062     * @return deep copy of this object
063     */
064    public MethodParameter copy() {
065        try {
066            return (MethodParameter) clone();
067        } catch (final CloneNotSupportedException e) {
068            // TODO should this throw?
069        }
070        return null;
071    }
072
073    /**
074     * Dump object to file stream on binary format.
075     *
076     * @param file Output file stream
077     * @throws IOException if an I/O error occurs.
078     */
079    public final void dump(final DataOutputStream file) throws IOException {
080        file.writeShort(nameIndex);
081        file.writeShort(accessFlags);
082    }
083
084    public int getAccessFlags() {
085        return accessFlags;
086    }
087
088    public int getNameIndex() {
089        return nameIndex;
090    }
091
092    /**
093     * Returns the name of the parameter.
094     */
095    public String getParameterName(final ConstantPool constantPool) {
096        if (nameIndex == 0) {
097            return null;
098        }
099        return constantPool.getConstantUtf8(nameIndex).getBytes();
100    }
101
102    public boolean isFinal() {
103        return (accessFlags & Const.ACC_FINAL) != 0;
104    }
105
106    public boolean isMandated() {
107        return (accessFlags & Const.ACC_MANDATED) != 0;
108    }
109
110    public boolean isSynthetic() {
111        return (accessFlags & Const.ACC_SYNTHETIC) != 0;
112    }
113
114    public void setAccessFlags(final int accessFlags) {
115        this.accessFlags = accessFlags;
116    }
117
118    public void setNameIndex(final int nameIndex) {
119        this.nameIndex = nameIndex;
120    }
121}