| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| package org.apache.bcel.classfile; |
| |
| import java.io.DataInput; |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| |
| import org.apache.bcel.Const; |
| |
| /** |
| * This class is derived from <em>Attribute</em> and represents a constant |
| * value, i.e., a default value for initializing a class field. |
| * This class is instantiated by the <em>Attribute.readAttribute()</em> method. |
| * |
| * @version $Id$ |
| * @see Attribute |
| */ |
| public final class ConstantValue extends Attribute { |
| |
| private int constantvalue_index; |
| |
| |
| /** |
| * Initialize from another object. Note that both objects use the same |
| * references (shallow copy). Use clone() for a physical copy. |
| */ |
| public ConstantValue(final ConstantValue c) { |
| this(c.getNameIndex(), c.getLength(), c.getConstantValueIndex(), c.getConstantPool()); |
| } |
| |
| |
| /** |
| * Construct object from input stream. |
| * @param name_index Name index in constant pool |
| * @param length Content length in bytes |
| * @param input Input stream |
| * @param constant_pool Array of constants |
| * @throws IOException |
| */ |
| ConstantValue(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) |
| throws IOException { |
| this(name_index, length, input.readUnsignedShort(), constant_pool); |
| } |
| |
| |
| /** |
| * @param name_index Name index in constant pool |
| * @param length Content length in bytes |
| * @param constantvalue_index Index in constant pool |
| * @param constant_pool Array of constants |
| */ |
| public ConstantValue(final int name_index, final int length, final int constantvalue_index, |
| final ConstantPool constant_pool) { |
| super(Const.ATTR_CONSTANT_VALUE, name_index, length, constant_pool); |
| this.constantvalue_index = constantvalue_index; |
| } |
| |
| |
| /** |
| * Called by objects that are traversing the nodes of the tree implicitely |
| * defined by the contents of a Java class. I.e., the hierarchy of methods, |
| * fields, attributes, etc. spawns a tree of objects. |
| * |
| * @param v Visitor object |
| */ |
| @Override |
| public void accept( final Visitor v ) { |
| v.visitConstantValue(this); |
| } |
| |
| |
| /** |
| * Dump constant value attribute to file stream on binary format. |
| * |
| * @param file Output file stream |
| * @throws IOException |
| */ |
| @Override |
| public final void dump( final DataOutputStream file ) throws IOException { |
| super.dump(file); |
| file.writeShort(constantvalue_index); |
| } |
| |
| |
| /** |
| * @return Index in constant pool of constant value. |
| */ |
| public final int getConstantValueIndex() { |
| return constantvalue_index; |
| } |
| |
| |
| /** |
| * @param constantvalue_index the index info the constant pool of this constant value |
| */ |
| public final void setConstantValueIndex( final int constantvalue_index ) { |
| this.constantvalue_index = constantvalue_index; |
| } |
| |
| |
| /** |
| * @return String representation of constant value. |
| */ |
| @Override |
| public final String toString() { |
| Constant c = super.getConstantPool().getConstant(constantvalue_index); |
| String buf; |
| int i; |
| // Print constant to string depending on its type |
| switch (c.getTag()) { |
| case Const.CONSTANT_Long: |
| buf = String.valueOf(((ConstantLong) c).getBytes()); |
| break; |
| case Const.CONSTANT_Float: |
| buf = String.valueOf(((ConstantFloat) c).getBytes()); |
| break; |
| case Const.CONSTANT_Double: |
| buf = String.valueOf(((ConstantDouble) c).getBytes()); |
| break; |
| case Const.CONSTANT_Integer: |
| buf = String.valueOf(((ConstantInteger) c).getBytes()); |
| break; |
| case Const.CONSTANT_String: |
| i = ((ConstantString) c).getStringIndex(); |
| c = super.getConstantPool().getConstant(i, Const.CONSTANT_Utf8); |
| buf = "\"" + Utility.convertString(((ConstantUtf8) c).getBytes()) + "\""; |
| break; |
| default: |
| throw new IllegalStateException("Type of ConstValue invalid: " + c); |
| } |
| return buf; |
| } |
| |
| |
| /** |
| * @return deep copy of this attribute |
| */ |
| @Override |
| public Attribute copy( final ConstantPool _constant_pool ) { |
| final ConstantValue c = (ConstantValue) clone(); |
| c.setConstantPool(_constant_pool); |
| return c; |
| } |
| } |