| /* Copyright (C) 2003 Vladimir Roubtsov. All rights reserved. |
| * |
| * This program and the accompanying materials are made available under |
| * the terms of the Common Public License v1.0 which accompanies this distribution, |
| * and is available at http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * $Id: ConstantValueAttribute_info.java,v 1.1.1.1 2004/05/09 16:57:47 vlad_r Exp $ |
| */ |
| package com.vladium.jcd.cls.attribute; |
| |
| import java.io.IOException; |
| |
| import com.vladium.jcd.cls.ClassDef; |
| import com.vladium.jcd.cls.constant.CONSTANT_literal_info; |
| import com.vladium.jcd.lib.UDataInputStream; |
| import com.vladium.jcd.lib.UDataOutputStream; |
| |
| // ---------------------------------------------------------------------------- |
| /** |
| * The ConstantValue attribute is a fixed-length attribute used in the attributes |
| * table of the {@link com.vladium.jcd.cls.Field_info} structures. A ConstantValue |
| * attribute represents the value of a constant field that must be (explicitly or |
| * implicitly) static; that is, the ACC_STATIC bit in the flags item of the |
| * Field_info structure must be set. The field is not required to be final. There |
| * can be no more than one ConstantValue attribute in the attributes table of a |
| * given Field_info structure. The constant field represented by the Field_info |
| * structure is assigned the value referenced by its ConstantValue attribute as |
| * part of its initialization.<P> |
| * |
| * The ConstantValue attribute has the format |
| * <PRE> |
| * ConstantValue_attribute { |
| * u2 attribute_name_index; |
| * u4 attribute_length; |
| * u2 constantvalue_index; |
| * } |
| * </PRE> |
| * |
| * The value of the constantvalue_index item must be a valid index into the constant |
| * pool table. The constant pool entry at that index must give the constant value |
| * represented by this attribute.<P> |
| * |
| * The constant pool entry must be of a type appropriate to the field, as shown below: |
| * |
| * <TABLE> |
| * <TR><TH>Field Type</TH> <TH>Entry Type</TH></TR> |
| * <TR><TD>long</TD> <TD>CONSTANT_Long</TD></TR> |
| * <TR><TD>float</TD> <TD>CONSTANT_Float</TD></TR> |
| * <TR><TD>double</TD> <TD>CONSTANT_Double</TD></TR> |
| * <TR><TD>int, short, char, byte, boolean</TD> <TD>CONSTANT_Integer</TD></TR> |
| * <TR><TD>java.lang.String</TD> <TD>CONSTANT_String</TD></TR> |
| * </TABLE> |
| * |
| * @author (C) 2001, Vlad Roubtsov |
| */ |
| public |
| final class ConstantValueAttribute_info extends Attribute_info |
| { |
| // public: ................................................................ |
| |
| |
| public int m_value_index; |
| |
| |
| public ConstantValueAttribute_info (final int attribute_name_index, final int value_index) |
| { |
| super (attribute_name_index, 2); |
| |
| m_value_index = value_index; |
| } |
| |
| public CONSTANT_literal_info getValue (final ClassDef cls) |
| { |
| return (CONSTANT_literal_info) cls.getConstants ().get (m_value_index); |
| } |
| |
| public long length () |
| { |
| return 8; |
| } |
| |
| // Visitor: |
| |
| public void accept (final IAttributeVisitor visitor, final Object ctx) |
| { |
| visitor.visit (this, ctx); |
| } |
| |
| public String toString () |
| { |
| // TODO: return more data here |
| return "ConstantValueAttribute_info: [attribute_name_index = " + m_name_index + ", attribute_length = " + m_attribute_length + ']'; |
| |
| } |
| |
| // Cloneable: |
| |
| /** |
| * Performs a deep copy. |
| */ |
| public Object clone () |
| { |
| return super.clone (); |
| } |
| |
| // IClassFormatOutput: |
| |
| public void writeInClassFormat (final UDataOutputStream out) throws IOException |
| { |
| super.writeInClassFormat (out); |
| |
| out.writeU2 (m_value_index); |
| } |
| |
| // protected: ............................................................. |
| |
| // package: ............................................................... |
| |
| |
| ConstantValueAttribute_info (final int attribute_name_index, final long attribute_length, |
| final UDataInputStream bytes) |
| throws IOException |
| { |
| super (attribute_name_index, attribute_length); |
| |
| m_value_index = bytes.readU2 (); |
| if (DEBUG) System.out.println ("\tconstantvalue_index: " + m_value_index); |
| } |
| |
| // private: ............................................................... |
| |
| |
| private static final boolean DEBUG = false; |
| |
| } // end of class |
| // ---------------------------------------------------------------------------- |