Azureus源码剖析（一）

      整个项目运行的起点在com.aelitis.azureus.ui.Main这个类中，它只有一个main主方法，运用Java的反射机制来调用真正的起始点类org.gudy.azureus2.ui.swt.Main的实例对象。

代码如下：

final Class startupClass = Class.forName("org.gudy.azureus2.ui.swt.Main");

final Constructor constructor = startupClass.getConstructor(new Class[] {
    String[].class
});

constructor.newInstance(new Object[] {
    args
});

而在org.gudy.azureus2.ui.swt.Main这个类中有一个成员变量

StartServer startServer

它是一个监听服务器，对本地的6880端口进行监听，监听的对象是torrent种子文件的URL地址，在它的构造函数中有如下语句：

socket = new ServerSocket(6880, 50, InetAddress.getByName("127.0.0.1")); //种子文件监听服务器

    state = STATE_LISTENING; //服务器状态设置为“监听中”

对此我们来做个小实验，通过tcp连接到Azureus的种子文件监听服务器上，向它传递待下载的种子文件列表，从而让Azureus去下载。

package com.vista.test;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

/**
 *
 * @author phinecos
 * @since 2009-5-6
 *
 */
public class MyClass
{
    private String[] files = null;
    public MyClass(String[] files)
    {
        this.files = files;
    }
    @Override
    public String toString()
    {
        StringBuilder sb = new StringBuilder();
        for (String file: files)
        {
            sb.append(file);
        }
        return sb.toString();
    }
    public void sendMessage()
    {
        Socket socket = null;
        PrintWriter pw = null;
        String msg = "StartSocket: passing startup args to already-running Azureus java process listening on [127.0.0.1: 6880]";
        String IpAddr = "127.0.0.1";
        int port = 6880;
        final String ACCESS_STRING = "Azureus Start Server Access";

        try
        {
            socket = new Socket(IpAddr,port);
            pw = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(),"UTF8"));
            StringBuffer buffer = new StringBuffer(ACCESS_STRING + ";args;");

            for (int i = 0; i < files.length; ++i)
            {
                String file = files[i].replaceAll("&","&&").replaceAll(";","&;");//字符转义
                buffer.append(file);
                buffer.append(';');
            }
            pw.println(buffer.toString());
            pw.flush();

        }
        catch (UnknownHostException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        finally
        {
            try
            {
                if (pw != null)
                    pw.close();
            }
            catch(Exception e){}

            try
            {
                if (socket != null)
                    socket.close();
            }
            catch (IOException e) {}
        }

    }
}

 

package com.vista.test;

import java.lang.reflect.Constructor;

/**
 *
 * @author phinecos
 * @since 2009-5-6
 *
 */
public class Main
{

    /**
     * @param args
     * @throws ClassNotFoundException
     */
    public static void main(String[] args)
    {
        try
        {
            final Class myClass = Class.forName("com.vista.test.MyClass");
            final Constructor myConstructor = myClass.getConstructor(new Class[]{String[].class});
            String[] torrents = {"c:\\1001.torrent", "c:\\1002.torrent"};//种子文件列表
            MyClass c1 = (MyClass)myConstructor.newInstance(new Object[]{torrents});
            System.out.println(c1.toString());
            c1.sendMessage();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

    }

}

先启动Azureus,再使用此用例进行测试，结果如下图，这表明这两个种子文件都被解析并开始下载了。