Self ClassLoader : Class Path « Development Class « Java

1. Java
2. Development Class
3. Class Path

Self ClassLoader

     
/*
 * @(#)SelfClassLoader.java 2010-4-18
 * 
 * Copyright 5jxiang . All rights reserved.
 */
//package com.jz.util;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.channels.WritableByteChannel;

/**
 * <p>
 * <a href="SelfClassLoader.java.html"><i>View Source</i></a>
 * </p>
 *
 * @author 5jxiang
 * @version $Id$
 */
public class SelfClassLoader extends ClassLoader {
  protected Class findClass(String name) throws ClassNotFoundException {
      byte[] bytes = loadClassBytes(name);
      Class theClass = defineClass(name, bytes, 0, bytes.length);
      if (theClass == null)
      throw new ClassFormatError();
      return theClass;
   }
   private byte[] loadClassBytes(String className) throws
        ClassNotFoundException {
   try {
     String classFile = getClassFile(className);
     FileInputStream fis = new FileInputStream(classFile);
     FileChannel fileC = fis.getChannel();
     ByteArrayOutputStream baos = new
     ByteArrayOutputStream();
     WritableByteChannel outC = Channels.newChannel(baos);
     ByteBuffer buffer = ByteBuffer.allocate(1024);
     while (true) {
          int i = fileC.read(buffer);
          if (i == 0 || i == -1) {
           break;
           }
           buffer.flip();
           outC.write(buffer);
           buffer.clear();
         }
         fis.close();
         return baos.toByteArray();
       } catch (IOException fnfe) {
         throw new ClassNotFoundException(className);
       }
   }
   
  private String getClassFile(String name){
       StringBuffer sb = new StringBuffer(SelfClassLoader.class.getResource("/").getPath());
       name = name.replace('.', File.separator.charAt(0)) + ".class";
       sb.append(File.separator + name);
       return sb.toString();
     }
}

   
    
    
    
    
  

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