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/* 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: Field_info.java,v 1.1.1.1 2004/05/09 16:57:45 vlad_r Exp $
*/
package com.vladium.jcd.cls;
import java.io.IOException;
import com.vladium.jcd.cls.attribute.*;
import com.vladium.jcd.cls.constant.CONSTANT_Utf8_info;
import com.vladium.jcd.lib.UDataInputStream;
import com.vladium.jcd.lib.UDataOutputStream;
// ----------------------------------------------------------------------------
/**
* Each class field is described by a variable-length field_info structure. The
* format of this structure is
* <PRE>
* field_info {
* u2 access_flags;
* u2 name_index;
* u2 descriptor_index;
* u2 attributes_count;
* attribute_info attributes[attributes_count];
* }
* </PRE>
*
* The value of the access_flags item is a mask of modifiers used to describe
* access permission to and properties of a field.<P>
*
* The value of the name_index item must be a valid index into the constant pool
* table. The constant pool entry at that index must be a {@link CONSTANT_Utf8_info}
* structure which must represent a valid Java field name stored as a simple (not
* fully qualified) name, that is, as a Java identifier.<P>
*
* The value of the descriptor_index item must be a valid index into the constant
* pool table. The constant pool entry at that index must be a
* {@link CONSTANT_Utf8_info} structure which must represent a valid Java field
* descriptor.<P>
*
* Each value of the attributes table must be a variable-length attribute structure.
* A field can have any number of attributes associated with it. The only attribute
* defined for the attributes table of a field_info structure at the moment
* is the ConstantValue attribute -- see {@link ConstantValueAttribute_info}.
*
* @author (C) 2001, Vlad Roubtsov
*/
public
final class Field_info implements Cloneable, IAccessFlags
{
// public: ................................................................
public int m_name_index;
public int m_descriptor_index;
public Field_info (final int access_flags,
final int name_index, final int descriptor_index,
final IAttributeCollection attributes)
{
m_access_flags = access_flags;
m_name_index = name_index;
m_descriptor_index = descriptor_index;
m_attributes = attributes;
}
public Field_info (final IConstantCollection constants,
final UDataInputStream bytes)
throws IOException
{
m_access_flags = bytes.readU2 ();
m_name_index = bytes.readU2 ();
m_descriptor_index = bytes.readU2 ();
// TODO: put this logic into AttributeCollection
final int attributes_count = bytes.readU2 ();
m_attributes = ElementFactory.newAttributeCollection (attributes_count);
for (int i = 0; i < attributes_count; i++)
{
final Attribute_info attribute_info = Attribute_info.new_Attribute_info (constants, bytes);
if (DEBUG) System.out.println ("\t[" + i + "] attribute: " + attribute_info);
m_attributes.add (attribute_info);
}
}
/**
* Returns the field name within the context of 'cls' class definition.
*
* @param cls class that contains this field
* @return field name
*/
public String getName (final ClassDef cls)
{
return ((CONSTANT_Utf8_info) cls.getConstants ().get (m_name_index)).m_value;
}
/**
* Returns the descriptor string for this field within the context of 'cls'
* class definition.
*
* @param cls class that contains this field
* @return field typename descriptor
*/
public String getDescriptor (final ClassDef cls)
{
return ((CONSTANT_Utf8_info) cls.getConstants ().get (m_descriptor_index)).m_value;
}
public boolean isSynthetic ()
{
return m_attributes.hasSynthetic ();
}
// IAccessFlags:
public final void setAccessFlags (final int flags)
{
m_access_flags = flags;
}
public final int getAccessFlags ()
{
return m_access_flags;
}
public IAttributeCollection getAttributes ()
{
return m_attributes;
}
public String toString ()
{
return "field_info: [modifiers: 0x" + Integer.toHexString(m_access_flags) + ", name_index = " + m_name_index + ", descriptor_index = " + m_descriptor_index + ']';
}
// Cloneable:
/**
* Performs a deep copy.
*/
public Object clone ()
{
try
{
final Field_info _clone = (Field_info) super.clone ();
// do deep copy:
_clone.m_attributes = (IAttributeCollection) m_attributes.clone ();
return _clone;
}
catch (CloneNotSupportedException e)
{
throw new InternalError (e.toString ());
}
}
// IClassFormatOutput:
public void writeInClassFormat (final UDataOutputStream out) throws IOException
{
out.writeU2 (m_access_flags);
out.writeU2 (m_name_index);
out.writeU2 (m_descriptor_index);
m_attributes.writeInClassFormat (out);
}
// protected: .............................................................
// package: ...............................................................
// private: ...............................................................
private int m_access_flags;
private IAttributeCollection m_attributes; // never null
private static final boolean DEBUG = false;
} // end of class
// ----------------------------------------------------------------------------
|
