synthetic.java

代码是一个分类器的实现,其中使用了部分weka的源代码。可以将项目导入eclipse运行

package de.fub.bytecode.classfile;

import  de.fub.bytecode.Constants;
import  java.io.*;

/**
 * This class is derived from <em>Attribute</em> and declares this class
 * as `synthetic', i.e., it needs special handling.
 * It is instantiated from the <em>Attribute.readAttribute()</em> method.
 *
 * @version $Id: Synthetic.java,v 1.4 2001/06/25 07:58:16 dahm Exp $
 * @author  <A HREF="http://www.berlin.de/~markus.dahm/">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.
   */
  public Synthetic(Synthetic c) {
    this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool());
  }

  /**
   * @param name_index Index in constant pool to CONSTANT_Utf8
   * @param length Content length in bytes
   * @param bytes Attribute contents
   * @param constant_pool Array of constants
   * @param sourcefile_index Index in constant pool to CONSTANT_Utf8
   */
  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.
   * @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
   * @throw 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.
   *
   * @param v Visitor object
   */
  public void accept(Visitor v) {
    v.visitSynthetic(this);
  }    
  /**
   * Dump source file attribute to file stream in binary format.
   *
   * @param file Output file stream
   * @throw IOException
   */ 
  public final void dump(DataOutputStream file) throws IOException
  {
    super.dump(file);
    if(length > 0)
      file.write(bytes, 0, length);
  }    
  /**
   * @return data bytes.
   */  
  public final byte[] getBytes() { return bytes; }    

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

  /**
   * @return String representation.
   */ 
  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.constant_pool = constant_pool;
    return c;
  }
}