    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_ARRAY = {};
    042
    043    private MethodParameter[] parameters = EMPTY_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        final int parameterCount = input.readUnsignedByte();
    048        parameters = new MethodParameter[parameterCount];
    049        for (int i = 0; i < parameterCount; i++) {
    050            parameters[i] = new MethodParameter(input);
    051        }
    052    }
    053
    054    @Override
    055    public void accept(final Visitor v) {
    056        v.visitMethodParameters(this);
    057    }
    058
    059    @Override
    060    public Attribute copy(final ConstantPool constantPool) {
    061        final MethodParameters c = (MethodParameters) clone();
    062        c.parameters = new MethodParameter[parameters.length];
    063        Arrays.setAll(c.parameters, i -> parameters[i].copy());
    064        c.setConstantPool(constantPool);
    065        return c;
    066    }
    067
    068    /**
    069     * Dump method parameters attribute to file stream in binary format.
    070     *
    071     * @param file Output file stream
    072     * @throws IOException if an I/O error occurs.
    073     */
    074    @Override
    075    public void dump(final DataOutputStream file) throws IOException {
    076        super.dump(file);
    077        file.writeByte(parameters.length);
    078        for (final MethodParameter parameter : parameters) {
    079            parameter.dump(file);
    080        }
    081    }
    082
    083    public MethodParameter[] getParameters() {
    084        return parameters;
    085    }
    086
    087    @Override
    088    public Iterator<MethodParameter> iterator() {
    089        return Stream.of(parameters).iterator();
    090    }
    091
    092    public void setParameters(final MethodParameter[] parameters) {
    093        this.parameters = parameters != null ? parameters : EMPTY_ARRAY;
    094    }
    095}