同步阻塞通信-伪异步I/O编程

1. 伪异步通信其底层实现还是同步通信，同步通信一请求一应答的特性让每一个客户端请求服务端都需要请起一个线程处理，在高并发的情况下极易容易导致系统资源耗尽而导致宕机等现象，伪异步是通过一个客户端线程池，让线程池中的一个线程处理多个客户端请求，高并发情况下系统线程资源消耗不会增加。
2. 服务器实现

package com.haidong.forged_bio;import com.haidong.bio.TimeServerHandler;import java.net.ServerSocket;import java.net.Socket;/** * TimeServer * * @author Lance * @date 2017/05/31 */public class TimeServer {    public static void main(String[] args) throws Exception {        int port = 8080;        if(args.length > 0 && args != null){            try {                port = Integer.valueOf(port);            } catch (NumberFormatException e) {                //采用默认值                e.printStackTrace();            }        }        ServerSocket server = null;        try {            server = new ServerSocket(port);            System.out.println("时间服务器开启：" + port);            Socket socket = null;            TimeServerHandlerExecutePool singleExecutor = new  TimeServerHandlerExecutePool(50, 10000);            while (true){                //监听                socket = server.accept();                singleExecutor.execute(new com.haidong.forged_bio.TimeServerHandler(socket));            }        } finally {            if(server != null){                System.out.println("关闭服务器");                server.close();                server = null;            }        }    }}

3.线程池编码实现

package com.haidong.forged_bio;import java.util.concurrent.ArrayBlockingQueue;import java.util.concurrent.ExecutorService;import java.util.concurrent.ThreadPoolExecutor;import java.util.concurrent.TimeUnit;/** * TimeServerHandlerExcutePool * * @author Lance * @date 2017/05/31 */public class TimeServerHandlerExecutePool {    private ExecutorService executor;    public TimeServerHandlerExecutePool(int maxPollSize, int queueSize){        executor = new ThreadPoolExecutor(Runtime.getRuntime().availableProcessors(), maxPollSize, 120L, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(queueSize));    }    public void execute(Runnable task){        executor.execute(task);    }}

4.业务处理

package com.haidong.forged_bio;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.Socket;import java.util.Date;/** * TimeServerHandler * * @author Lance * @date 2017/05/31 */public class TimeServerHandler implements Runnable {    private Socket socket;    public TimeServerHandler(Socket socket) {        this.socket = socket;    }    public void run() {        BufferedReader in = null;        PrintWriter out = null;        try {            in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));            out = new PrintWriter(this.socket.getOutputStream(), true);            String currentTime = null;            String body = null;            while (true){                //读取                body = in.readLine();                if (body == null){                    break;                }                System.out.println("服务器接收到客户端内容：" + body);                currentTime = "QUERY TIME ORDER".equalsIgnoreCase(body) ? new Date(System.currentTimeMillis()).toString() : "BAD ORDER";                out.println(currentTime);            }        } catch (IOException e) {            e.printStackTrace();            if(in != null){                try {                    in.close();                } catch (IOException e1) {                    e1.printStackTrace();                }                in = null;            }            if(out != null){                out.close();                out = null;            }            if(this.socket != null){                try {                    socket.close();                } catch (IOException e1) {                    e1.printStackTrace();                }                socket = null;            }        }    }}

5.客户端

package com.haidong.forged_bio;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.Socket;/** * TimeClient * * @author Lance * @date 2017/05/31 */public class TimeClient {    public static void main(String[] args) {        int port = 8080;        if(args.length > 0 && args != null){            try {                port = Integer.valueOf(port);            } finally {                //默认值            }        }        Socket socket = null;        BufferedReader in = null;        PrintWriter out = null;        try {            socket = new Socket("127.0.0.1", port);            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));            out = new PrintWriter(socket.getOutputStream(), true);            out.println("QUERY TIME ORDER");            System.out.println("查询时间success");            String resp = in.readLine();            System.out.println("当前时间" + resp);        } catch (IOException e) {            e.printStackTrace();        } finally {          if(out != null){              out.close();              out = null;          }          if(in != null){              try {                  in.close();              } catch (IOException e) {                  e.printStackTrace();              }              in = null;          }          if(socket != null){              try {                  socket.close();              } catch (IOException e) {                  e.printStackTrace();              }              socket = null;          }        }    }}

6.运行服务端和客户端结果