网络编程复习（二）：JDK1.5之前的伪异步BIO编程

在JDK1.5之前并没有提供NIO非阻塞异步通信，在这里说一下什么是BIO：就是同步阻塞形式的通信模式，那么什么是NIO，就是同步非阻塞通信模式，同时，在JDK1.7之后，支持异步非阻塞通信模式，就是所说的NIO2.0.那么是怎么实现多个client连接服务器的呢？答案是使用的是伪异步方式，即自定义线程池加队列方式，下面看看代码：

client类：与上一篇没有任何变化

package 网络编程_最原始BIO2;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.Socket;public class Client {public static void main(String[] args) {PrintWriter writer = null;BufferedReader reader = null;Socket client = null;try {client = new Socket("127.0.0.1", 8888);writer = new PrintWriter(client.getOutputStream(), true);//该地方必须加true，设置为自动刷新reader = new BufferedReader(new InputStreamReader(client.getInputStream()));writer.println("接收客户端发送请求");System.out.println("请求已经发出");String body = reader.readLine();System.out.println(body);} catch (Exception e) {e.printStackTrace();} finally {if (reader != null) {try {client.close();} catch (IOException e) {e.printStackTrace();}}if (writer != null) {writer.close();}if (client != null) {try {reader.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}client = null;}}}}

server类：

package 网络编程_最原始BIO2;import java.io.IOException;import java.net.ServerSocket;import java.net.Socket;import 网络编程_最原始.HanderSocket;public class Server {static ServerSocket server = null;public static void main(String[] args) {try {server = new ServerSocket(8888);System.out.println("server start...");while(true){Socket socket = server.accept();new HanderPoolExecuter(50, 1000).executors(new HanderSocket(socket));}} catch (IOException e) {e.printStackTrace();}finally {if(server!=null){try {server.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}server = null;}}}}

HandlerPoolExecutor自定义线程池类：

package 网络编程_最原始BIO2;import java.util.concurrent.ArrayBlockingQueue;import java.util.concurrent.BlockingQueue;import java.util.concurrent.ExecutorService;import java.util.concurrent.ThreadPoolExecutor;import java.util.concurrent.TimeUnit;public class HanderPoolExecuter {    Integer initSize;Integer maxSize;private ExecutorService executorService;private BlockingQueue<Runnable> blockingQueue = new ArrayBlockingQueue<>(1000);public HanderPoolExecuter(int initSize,int maxSize){this.initSize = initSize;this.maxSize = maxSize;executorService = new ThreadPoolExecutor(initSize, maxSize, 60, TimeUnit.SECONDS, blockingQueue);}public void executors(Runnable task){executorService.execute(task);}}

任务类HandlerSocket类，没有任何变化：

package 网络编程_最原始BIO2;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.Socket;public class HanderSocket implements Runnable{Socket socket = null;public  HanderSocket(Socket socket) {this.socket = socket;}@Overridepublic void run() {BufferedReader reader = null;PrintWriter writer = null;try {reader = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));writer = new PrintWriter(this.socket.getOutputStream(),true);String body = null;while(true){body = reader.readLine();if(body == null) break;System.out.println(body);writer.println("你好，服务端已经接收到你的请求");System.out.println("已经向客户端反馈结果");}} catch (Exception e) {e.printStackTrace();}finally {if(writer !=null){writer.close();}if(reader !=null){try {reader.close();} catch (IOException e) {e.printStackTrace();}}if(socket!=null){try {socket.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}socket = null;}}}}

这种伪异步的方式其实还是阻塞形式的，并不适合当前开发场景，下一篇将介绍JDK1.7之后提供的非阻塞异步NIO通信方式。