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}