    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 */
    019
    020package org.apache.bcel.classfile;
    021
    022import java.io.DataInput;
    023import java.io.DataOutputStream;
    024import java.io.IOException;
    025
    026import org.apache.bcel.Const;
    027
    028/**
    029 * Entry of the parameters table.
    030 * <p>
    031 * Implements {@link Node} as of 6.7.0.
    032 * </p>
    033 *
    034 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.24"> The class File Format :
    035 *      The MethodParameters Attribute</a>
    036 * @since 6.0
    037 */
    038public class MethodParameter implements Cloneable, Node {
    039
    040    /** Index of the CONSTANT_Utf8_info structure in the constant_pool table representing the name of the parameter */
    041    private int nameIndex;
    042
    043    /** The access flags */
    044    private int accessFlags;
    045
    046    public MethodParameter() {
    047    }
    048
    049    /**
    050     * Constructs an instance from a DataInput.
    051     *
    052     * @param input Input stream
    053     * @throws IOException if an I/O error occurs.
    054     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
    055     */
    056    MethodParameter(final DataInput input) throws IOException {
    057        nameIndex = input.readUnsignedShort();
    058        accessFlags = input.readUnsignedShort();
    059    }
    060
    061    @Override
    062    public void accept(final Visitor v) {
    063        v.visitMethodParameter(this);
    064    }
    065
    066    /**
    067     * @return deep copy of this object
    068     */
    069    public MethodParameter copy() {
    070        try {
    071            return (MethodParameter) clone();
    072        } catch (final CloneNotSupportedException e) {
    073            // TODO should this throw?
    074        }
    075        return null;
    076    }
    077
    078    /**
    079     * Dumps object to file stream on binary format.
    080     *
    081     * @param file Output file stream
    082     * @throws IOException if an I/O error occurs.
    083     */
    084    public final void dump(final DataOutputStream file) throws IOException {
    085        file.writeShort(nameIndex);
    086        file.writeShort(accessFlags);
    087    }
    088
    089    public int getAccessFlags() {
    090        return accessFlags;
    091    }
    092
    093    public int getNameIndex() {
    094        return nameIndex;
    095    }
    096
    097    /**
    098     * Gets the name of the parameter.
    099     *
    100     * @param constantPool The pool to query.
    101     * @return Constant from the given pool.
    102     */
    103    public String getParameterName(final ConstantPool constantPool) {
    104        if (nameIndex == 0) {
    105            return null;
    106        }
    107        return constantPool.getConstantUtf8(nameIndex).getBytes();
    108    }
    109
    110    public boolean isFinal() {
    111        return (accessFlags & Const.ACC_FINAL) != 0;
    112    }
    113
    114    public boolean isMandated() {
    115        return (accessFlags & Const.ACC_MANDATED) != 0;
    116    }
    117
    118    public boolean isSynthetic() {
    119        return (accessFlags & Const.ACC_SYNTHETIC) != 0;
    120    }
    121
    122    public void setAccessFlags(final int accessFlags) {
    123        this.accessFlags = accessFlags;
    124    }
    125
    126    public void setNameIndex(final int nameIndex) {
    127        this.nameIndex = nameIndex;
    128    }
    129}