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 * This class represents an entry in the requires table of the Module attribute. Each entry describes a module on which 028 * the parent module depends. 029 * 030 * @see Module 031 * @since 6.4.0 032 */ 033public final class ModuleRequires implements Cloneable, Node { 034 035 private final int requiresIndex; // points to CONSTANT_Module_info 036 private final int requiresFlags; 037 private final int requiresVersionIndex; // either 0 or points to CONSTANT_Utf8_info 038 039 /** 040 * Constructs object from file stream. 041 * 042 * @param file Input stream 043 * @throws IOException if an I/O Exception occurs in readUnsignedShort 044 */ 045 ModuleRequires(final DataInput file) throws IOException { 046 requiresIndex = file.readUnsignedShort(); 047 requiresFlags = file.readUnsignedShort(); 048 requiresVersionIndex = file.readUnsignedShort(); 049 } 050 051 /** 052 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. 053 * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects. 054 * 055 * @param v Visitor object 056 */ 057 @Override 058 public void accept(final Visitor v) { 059 v.visitModuleRequires(this); 060 } 061 062 // TODO add more getters and setters? 063 064 /** 065 * @return deep copy of this object 066 */ 067 public ModuleRequires copy() { 068 try { 069 return (ModuleRequires) clone(); 070 } catch (final CloneNotSupportedException e) { 071 // TODO should this throw? 072 } 073 return null; 074 } 075 076 /** 077 * Dump table entry to file stream in binary format. 078 * 079 * @param file Output file stream 080 * @throws IOException if an I/O Exception occurs in writeShort 081 */ 082 public void dump(final DataOutputStream file) throws IOException { 083 file.writeShort(requiresIndex); 084 file.writeShort(requiresFlags); 085 file.writeShort(requiresVersionIndex); 086 } 087 088 /** 089 * @return String representation 090 */ 091 @Override 092 public String toString() { 093 return "requires(" + requiresIndex + ", " + String.format("%04x", requiresFlags) + ", " + requiresVersionIndex + ")"; 094 } 095 096 /** 097 * @return Resolved string representation 098 */ 099 public String toString(final ConstantPool constantPool) { 100 final StringBuilder buf = new StringBuilder(); 101 final String moduleName = constantPool.constantToString(requiresIndex, Const.CONSTANT_Module); 102 buf.append(Utility.compactClassName(moduleName, false)); 103 buf.append(", ").append(String.format("%04x", requiresFlags)); 104 final String version = requiresVersionIndex == 0 ? "0" : constantPool.getConstantString(requiresVersionIndex, Const.CONSTANT_Utf8); 105 buf.append(", ").append(version); 106 return buf.toString(); 107 } 108}