1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 package org.apache.bcel.classfile; 19 20 import java.io.DataInput; 21 import java.io.DataOutputStream; 22 import java.io.IOException; 23 24 import org.apache.bcel.Const; 25 26 /** 27 * This class is derived from the abstract {@link Constant} 28 * and represents a reference to a module. 29 * 30 * <p>Note: Early access Java 9 support- currently subject to change</p> 31 * 32 * @see Constant 33 * @since 6.1 34 */ 35 public final class ConstantModule extends Constant implements ConstantObject { 36 37 private int name_index; 38 39 40 /** 41 * Initialize from another object. 42 */ ConstantModule(final ConstantModule c)43 public ConstantModule(final ConstantModule c) { 44 this(c.getNameIndex()); 45 } 46 47 48 /** 49 * Initialize instance from file data. 50 * 51 * @param file Input stream 52 * @throws IOException 53 */ ConstantModule(final DataInput file)54 ConstantModule(final DataInput file) throws IOException { 55 this(file.readUnsignedShort()); 56 } 57 58 59 /** 60 * @param name_index Name index in constant pool. Should refer to a 61 * ConstantUtf8. 62 */ ConstantModule(final int name_index)63 public ConstantModule(final int name_index) { 64 super(Const.CONSTANT_Module); 65 this.name_index = name_index; 66 } 67 68 69 /** 70 * Called by objects that are traversing the nodes of the tree implicitly 71 * defined by the contents of a Java class. I.e., the hierarchy of methods, 72 * fields, attributes, etc. spawns a tree of objects. 73 * 74 * @param v Visitor object 75 */ 76 @Override accept( final Visitor v )77 public void accept( final Visitor v ) { 78 v.visitConstantModule(this); 79 } 80 81 82 /** 83 * Dump constant module to file stream in binary format. 84 * 85 * @param file Output file stream 86 * @throws IOException 87 */ 88 @Override dump( final DataOutputStream file )89 public final void dump( final DataOutputStream file ) throws IOException { 90 file.writeByte(super.getTag()); 91 file.writeShort(name_index); 92 } 93 94 95 /** 96 * @return Name index in constant pool of module name. 97 */ getNameIndex()98 public final int getNameIndex() { 99 return name_index; 100 } 101 102 103 /** 104 * @param name_index the name index in the constant pool of this Constant Module 105 */ setNameIndex( final int name_index )106 public final void setNameIndex( final int name_index ) { 107 this.name_index = name_index; 108 } 109 110 111 /** @return String object 112 */ 113 @Override getConstantValue( final ConstantPool cp )114 public Object getConstantValue( final ConstantPool cp ) { 115 final Constant c = cp.getConstant(name_index, Const.CONSTANT_Utf8); 116 return ((ConstantUtf8) c).getBytes(); 117 } 118 119 120 /** @return dereferenced string 121 */ getBytes( final ConstantPool cp )122 public String getBytes( final ConstantPool cp ) { 123 return (String) getConstantValue(cp); 124 } 125 126 127 /** 128 * @return String representation. 129 */ 130 @Override toString()131 public final String toString() { 132 return super.toString() + "(name_index = " + name_index + ")"; 133 } 134 } 135