    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;
    023import java.util.Arrays;
    024import java.util.Iterator;
    025import java.util.stream.Stream;
    026
    027import org.apache.bcel.Const;
    028
    029/**
    030 * This class represents a MethodParameters attribute.
    031 *
    032 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.24"> The class File Format :
    033 *      The MethodParameters Attribute</a>
    034 * @since 6.0
    035 */
    036public class MethodParameters extends Attribute implements Iterable<MethodParameter> {
    037
    038    /**
    039     * Empty array.
    040     */
    041    private static final MethodParameter[] EMPTY_METHOD_PARAMETER_ARRAY = {};
    042
    043    private MethodParameter[] parameters = EMPTY_METHOD_PARAMETER_ARRAY;
    044
    045    MethodParameters(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
    046        super(Const.ATTR_METHOD_PARAMETERS, nameIndex, length, constantPool);
    047
    048        final int parameterCount = input.readUnsignedByte();
    049        parameters = new MethodParameter[parameterCount];
    050        for (int i = 0; i < parameterCount; i++) {
    051            parameters[i] = new MethodParameter(input);
    052        }
    053    }
    054
    055    @Override
    056    public void accept(final Visitor v) {
    057        v.visitMethodParameters(this);
    058    }
    059
    060    @Override
    061    public Attribute copy(final ConstantPool constantPool) {
    062        final MethodParameters c = (MethodParameters) clone();
    063        c.parameters = new MethodParameter[parameters.length];
    064
    065        Arrays.setAll(c.parameters, i -> parameters[i].copy());
    066        c.setConstantPool(constantPool);
    067        return c;
    068    }
    069
    070    /**
    071     * Dump method parameters attribute to file stream in binary format.
    072     *
    073     * @param file Output file stream
    074     * @throws IOException if an I/O error occurs.
    075     */
    076    @Override
    077    public void dump(final DataOutputStream file) throws IOException {
    078        super.dump(file);
    079        file.writeByte(parameters.length);
    080        for (final MethodParameter parameter : parameters) {
    081            parameter.dump(file);
    082        }
    083    }
    084
    085    public MethodParameter[] getParameters() {
    086        return parameters;
    087    }
    088
    089    @Override
    090    public Iterator<MethodParameter> iterator() {
    091        return Stream.of(parameters).iterator();
    092    }
    093
    094    public void setParameters(final MethodParameter[] parameters) {
    095        this.parameters = parameters;
    096    }
    097}