Socket简单用法

Socket通常也称做”套接字“，用于描述IP地址和端口，废话不多说，它就是网络通信过程中端点的抽象表示。值得一提的是，Java在包java.net中提供了两个类Socket和ServerSocket，分别用来表示双向连接的客户端和服务端。这是两个封装得非常好的类，使用起来很方便！
下面将首先创建一个SocketServer的类作为服务端如下，该服务端实现了多线程机制，可以在特定端口处监听多个客户请求，一旦有客户请求，Server总是会创建一个服务纯种来服务新来的客户，而自己继续监听。程序中accept()是一个阻塞函数，所谓阻塞性方法就是说该方法被调用后将等待客户的请求，直到有一个客户启动并请求连接到相同的端口，然后accept()返回一个对应于客户的Socket。这时，客户方和服务方都建立了用于通信的Socket，接下来就是由各个Socket分别打开各自的输入、输出流。

package com.wop.ddddddd;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.net.ServerSocket;

import java.net.Socket;

public class SocketServer {

// SocketServer类，服务器实现：

ServerSocket sever;

public SocketServer(int port) {

try {

sever = new ServerSocket(port);

} catch (IOException e) {

e.printStackTrace();

}

}

public void beginListen() {

while (true) {

try {

final Socket socket = sever.accept();

new Thread(new Runnable() {

public void run() {

BufferedReader in;

try {

in = new BufferedReader(new InputStreamReader(

socket.getInputStream(), "UTF-8"));

PrintWriter out = new PrintWriter(

socket.getOutputStream());

while (!socket.isClosed()) {

String str;

str = in.readLine();

out.println("Hello!world!! " + str);

out.flush();

if (str == null || str.equals("end"))

break;

System.out.println(str);

}

socket.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}).start();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

package com.wop.ddddddd;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.net.Socket;

import java.net.UnknownHostException;

public class SocketClient {

static Socket client;

// SocketClient类，客户端实现：

public SocketClient(String site, int port) {

try {

client = new Socket(site, port);

System.out.println("Client is created! site:" + site + " port:"

+ port);

} catch (UnknownHostException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

}

public String sendMsg(String msg) {

try {

BufferedReader in = new BufferedReader(new InputStreamReader(

client.getInputStream()));

PrintWriter out = new PrintWriter(client.getOutputStream());

out.println(msg);

out.flush();

return in.readLine();

} catch (IOException e) {

e.printStackTrace();

}

return "";

}

public void closeSocket() {

try {

client.close();

} catch (IOException e) {

e.printStackTrace();

}

}

public static void main(String[] args) throws Exception {

}

}

package com.wop.ddddddd;

public class TestSocketClient {

// 再运行TestSocketClient类：

public static void main(String[] args) {

SocketClient client = new SocketClient("127.0.0.1", 12345);

System.out.println(client.sendMsg("nimei1"));

client.closeSocket();

SocketClient client1 = new SocketClient("127.0.0.1", 12345);

System.out.println(client1.sendMsg("nimei1111"));

client1.closeSocket();

SocketClient client11 = new SocketClient("127.0.0.1", 12345);

System.out.println(client11.sendMsg("nimei11111111"));

client11.closeSocket();

SocketClient client111 = new SocketClient("127.0.0.1", 12345);

System.out.println(client111.sendMsg("nimei11111111111111111"));

client111.closeSocket();

}

}

package com.wop.ddddddd;

public class TestSocketServer {

// 接下来就是来测试Socket通信了！

// 先运行TestSocketServer类，打开服务端，在12345端口处监听！

public static void main(String[] argvs) {

SocketServer server = new SocketServer(12345);

server.beginListen();

}

}