Server Transport model

介绍

Server Transport 即传输层，是建立在通信信道建立成功和传输指令交互成功的基础上的一层用于传送数据的层，类似TCP、UDP，它的主要的作用就是输送我们定义的数据，数据格式的数据结构则可以自己进行约定，如字符流、字节流等，也可以为XML或其他数据结构实现的数据格式。

 

在Transport建立过程中，Server与Client端需要持有一些数据成员，如对方的信任信息、连接地址等socket参数、操作柄的代理工厂。

 

这样建立Transport后则可以实现数据传输、指令下达、报告提交等功能。

 

部分代码

 

package thread;

import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
* This ServerTransport is work in multi thread env    
*    
* @author daniel
*
*/
public class ServerTransport {
    
  private static final Log _log = LogFactory.getLog(ServerTransport.class);
    
  private final Object _lock = new Object();
    
  private boolean _readyFlag = false;
        
        private boolean _stopFlag;
        
        private final AsynchronousCaller _asyncCaller;

        /**
         * Initialization AsynchronousCaller
         * @param asyncThreadPoolSize
         */
  public ServerTransport(int asyncThreadPoolSize) {
    if(asyncThreadPoolSize<0){
      throw new IllegalArgumentException("illegal Server Transport poolSize: "+asyncThreadPoolSize);
    }
    _asyncCaller = new AsynchronousCaller(asyncThreadPoolSize);
    
    //Do some other things about each transport!
    
  }

  /*
    *    Operate Handler
    */
  //check ready
  public boolean isReady(){
    synchronized(_lock){
      return _readyFlag;
    }
  }
    
  //start
        public void start() throws Exception {
                if (isStopped()) {
                        return;
                }
                
                _asyncCaller.start();
    
                setReady(true);
        }
        
        //stop
        public void stop() {
          _asyncCaller.stop();
            
          setReady(false);
          setStop(false);
        }
        
        //set ready
  private void setReady(boolean b) {
    synchronized(_lock){
      _readyFlag = b;
    }
  }
    
  //set ready
  private void setStop(boolean b) {
    synchronized(_lock){
      _stopFlag = b;
    }
  }
    
  //check stop
  private boolean isStopped() {
    synchronized(_lock){
      return _stopFlag;
    }
  }
}

/*
* Construct an Asynchronous Operate way
*/
class AsynchronousCaller {

        private final ThreadPoolExecutor _executor;
        
        /*
         * Generate an Thread pool with some thread factory & thread group    
         */
        public AsynchronousCaller(int poolSize) {
                if (poolSize <= 0) {
                        throw new IllegalArgumentException("illegal pool size: "+poolSize);
                }
                
                ThreadGroup threadGroup = new ThreadGroup("Async Caller Group");
                
                ThreadGroupFactory tFactory= new ThreadGroupFactory(threadGroup, "AsyncCaller-");
                
                tFactory.createDaemonThreads(true);
                
                _executor =    new ThreadPoolExecutor(poolSize,    
                                                                                        poolSize,    
                                                                                        Long.MAX_VALUE,    
                                                                                        TimeUnit.NANOSECONDS,    
                                                                                        new LinkedBlockingQueue(),    
                                                                                        tFactory,
                                                                                        new ThreadPoolExecutor.AbortPolicy());
        }

        public void start() {
                _executor.prestartAllCoreThreads();
        }
        
        public void stop() {
                _executor.shutdown();
        }        
}

 

public static void main(String[] args) {
    int serverTransNum = 3;
    ServerTransport serverTran = new ServerTransport(serverTransNum);
    if(!serverTran.isReady()){
      try {
        serverTran.start();
        
        Thread.sleep(2000);
        
        serverTran.stop();
      } catch (Exception e) {
        throw new RuntimeException("Unable to start server transport", e);
      }
    }
    
  }