多线程Java Socket编程示例

这篇做为学习孙卫琴<<Java网络编程精解>>的学习笔记吧.其中采用Java 5的ExecutorService来进行线程池的方式实现多线程,模拟客户端多用户向同一服务器端发送请求.

1.服务端

package sterning;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net. * ;
import java.util.concurrent. * ;

public class MultiThreadServer {
private int port = 8821 ;
private ServerSocketserverSocket;
private ExecutorServiceexecutorService; // 线程池
private final int POOL_SIZE = 10 ; // 单个CPU线程池大小

public MultiThreadServer() throws IOException {
serverSocket = new ServerSocket(port);
// Runtime的availableProcessor()方法返回当前系统的CPU数目.
executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * POOL_SIZE);
System.out.println( " 服务器启动 " );
}

public void service() {
while ( true ) {
Socketsocket = null ;
try {
// 接收客户连接,只要客户进行了连接,就会触发accept();从而建立连接
socket = serverSocket.accept();
executorService.execute( new Handler(socket));

} catch (Exceptione) {
e.printStackTrace();
}
}
}

public static void main(String[]args) throws IOException {
new MultiThreadServer().service();
}

}

class Handler implements Runnable {
private Socketsocket;
public Handler(Socketsocket) {
this .socket = socket;
}
private PrintWritergetWriter(Socketsocket) throws IOException {
OutputStreamsocketOut = socket.getOutputStream();
return new PrintWriter(socketOut, true );
}
private BufferedReadergetReader(Socketsocket) throws IOException {
InputStreamsocketIn = socket.getInputStream();
return new BufferedReader( new InputStreamReader(socketIn));
}
public Stringecho(Stringmsg) {
return " echo: " + msg;
}
public void run() {
try {
System.out.println( " Newconnectionaccepted " + socket.getInetAddress() + " : " + socket.getPort());
BufferedReaderbr = getReader(socket);
PrintWriterpw = getWriter(socket);
Stringmsg = null ;
while ((msg = br.readLine()) != null ) {
System.out.println(msg);
pw.println(echo(msg));
if (msg.equals( " bye " ))
break ;
}
} catch (IOExceptione) {
e.printStackTrace();
} finally {
try {
if (socket != null )
socket.close();
} catch (IOExceptione) {
e.printStackTrace();
}
}
}
}

2.客户端

package sterning;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class MultiThreadClient {

public static void main(String[]args) {
int numTasks = 10 ;

ExecutorServiceexec = Executors.newCachedThreadPool();

for ( int i = 0 ;i < numTasks;i ++ ) {
exec.execute(createTask(i));
}

}

// 定义一个简单的任务
private static RunnablecreateTask( final int taskID) {
return new Runnable() {
private Socketsocket = null ;
private int port = 8821 ;

public void run() {
System.out.println( " Task " + taskID + " :start " );
try {
socket = new Socket( " localhost " ,port);
// 发送关闭命令
OutputStreamsocketOut = socket.getOutputStream();
socketOut.write( " shutdown/r/n " .getBytes());

// 接收服务器的反馈
BufferedReaderbr = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
Stringmsg = null ;
while ((msg = br.readLine()) != null )
System.out.println(msg);
} catch (IOExceptione) {
e.printStackTrace();
}
}

} ;
}
}