http://www.aspectj.org: The AspectJ weaver introduces advices to java classes
  • Andy Clement 
package org.aspectj.apache.bcel.classfile;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import org.aspectj.apache.bcel.Constants;


This class is derived from Attribute and declares this class as `synthetic', i.e., it needs special handling. The JVM
specification states "A class member that does not appear in the source code must be marked using a Synthetic attribute." It may
appear in the ClassFile attribute table, a field_info table or a method_info table. This class is intended to be instantiated
from the Attribute.readAttribute() method.

Author:M. Dahm
See Also:
Version:$Id: Synthetic.java,v 1.5 2009/09/15 19:40:12 aclement Exp $
/**
 * This class is derived from <em>Attribute</em> and declares this class as `synthetic', i.e., it needs special handling. The JVM
 * specification states "A class member that does not appear in the source code must be marked using a Synthetic attribute." It may
 * appear in the ClassFile attribute table, a field_info table or a method_info table. This class is intended to be instantiated
 * from the <em>Attribute.readAttribute()</em> method.
 * 
 * @version $Id: Synthetic.java,v 1.5 2009/09/15 19:40:12 aclement Exp $
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see Attribute
 */
public final class Synthetic extends Attribute {
	private byte[] bytes;

	
Initialize from another object. Note that both objects use the same references (shallow copy). Use copy() for a physical
copy.

/**
	 * Initialize from another object. Note that both objects use the same references (shallow copy). Use copy() for a physical
	 * copy.
	 */
	public Synthetic(Synthetic c) {
		this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool());
	}

	//  
	// public Synthetic(ConstantPoolGen cpool) {
	// super(Constants.ATTR_SYNTHETIC, cpool.addUtf8("Synthetic"), 0, cpool);
	// ConstantPoolGen cpg = myGen.getConstantPool();
	// int index = ;
	// Attribute synthetic = new Synthetic(index, 0, new byte[0], cpg.getConstantPool());
	// }

	
Params:
  • name_index – Index in constant pool to CONSTANT_Utf8, which should represent the string "Synthetic".
  • length – Content length in bytes - should be zero.
  • bytes – Attribute contents
  • constant_pool – The constant pool this attribute is associated with.
/**
	 * @param name_index Index in constant pool to CONSTANT_Utf8, which should represent the string "Synthetic".
	 * @param length Content length in bytes - should be zero.
	 * @param bytes Attribute contents
	 * @param constant_pool The constant pool this attribute is associated with.
	 */
	public Synthetic(int name_index, int length, byte[] bytes, ConstantPool constant_pool) {
		super(Constants.ATTR_SYNTHETIC, name_index, length, constant_pool);
		this.bytes = bytes;
	}

	
Construct object from file stream.

Params:
  • name_index – Index in constant pool to CONSTANT_Utf8
  • length – Content length in bytes
  • file – Input stream
  • constant_pool – Array of constants
Throws:
/**
	 * Construct object from file stream.
	 * 
	 * @param name_index Index in constant pool to CONSTANT_Utf8
	 * @param length Content length in bytes
	 * @param file Input stream
	 * @param constant_pool Array of constants
	 * @throws IOException
	 */
	Synthetic(int name_index, int length, DataInputStream file, ConstantPool constant_pool) throws IOException {
		this(name_index, length, (byte[]) null, constant_pool);

		if (length > 0) {
			bytes = new byte[length];
			file.readFully(bytes);
			System.err.println("Synthetic attribute with length > 0");
		}
	}

	
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.

Params:
  • v – Visitor object
/**
	 * 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(ClassVisitor v) {
		v.visitSynthetic(this);
	}

	
Dump source file attribute to file stream in binary format.

Params:
  • file – Output file stream
Throws:
/**
	 * Dump source file attribute to file stream in binary format.
	 * 
	 * @param file Output file stream
	 * @throws IOException
	 */
	@Override
	public final void dump(DataOutputStream file) throws IOException {
		super.dump(file);
		if (length > 0)
			file.write(bytes, 0, length);
	}

	
Returns:data bytes.
/**
	 * @return data bytes.
	 */
	public final byte[] getBytes() {
		return bytes;
	}

	
@parambytes.
/**
	 * @param bytes.
	 */
	public final void setBytes(byte[] bytes) {
		this.bytes = bytes;
	}

	
Returns:String representation.
/**
	 * @return String representation.
	 */
	@Override
	public final String toString() {
		StringBuffer buf = new StringBuffer("Synthetic");

		if (length > 0)
			buf.append(" " + Utility.toHexString(bytes));

		return buf.toString();
	}

	// /**
	// * @return deep copy of this attribute
	// */
	// public Attribute copy(ConstantPool constant_pool) {
	// Synthetic c = (Synthetic)clone();
	//
	// if(bytes != null)
	// c.bytes = (byte[])bytes.clone();
	//
	// c.cpool = constant_pool;
	// return c;
	// }
}