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 {
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    public void accept(final Visitor v) {
057        v.visitMethodParameter(this);
058    }
059
060    /**
061     * @return deep copy of this object
062     */
063    public MethodParameter copy() {
064        try {
065            return (MethodParameter) clone();
066        } catch (final CloneNotSupportedException e) {
067            // TODO should this throw?
068        }
069        return null;
070    }
071
072    /**
073     * Dump object to file stream on binary format.
074     *
075     * @param file Output file stream
076     * @throws IOException if an I/O error occurs.
077     */
078    public final void dump(final DataOutputStream file) throws IOException {
079        file.writeShort(nameIndex);
080        file.writeShort(accessFlags);
081    }
082
083    public int getAccessFlags() {
084        return accessFlags;
085    }
086
087    public int getNameIndex() {
088        return nameIndex;
089    }
090
091    /**
092     * Returns the name of the parameter.
093     */
094    public String getParameterName(final ConstantPool constantPool) {
095        if (nameIndex == 0) {
096            return null;
097        }
098        return constantPool.getConstantUtf8(nameIndex).getBytes();
099    }
100
101    public boolean isFinal() {
102        return (accessFlags & Const.ACC_FINAL) != 0;
103    }
104
105    public boolean isMandated() {
106        return (accessFlags & Const.ACC_MANDATED) != 0;
107    }
108
109    public boolean isSynthetic() {
110        return (accessFlags & Const.ACC_SYNTHETIC) != 0;
111    }
112
113    public void setAccessFlags(final int accessFlags) {
114        this.accessFlags = accessFlags;
115    }
116
117    public void setNameIndex(final int nameIndex) {
118        this.nameIndex = nameIndex;
119    }
120}