【android】Socket简单用法

转自：http://www.cnblogs.com/harrisonpc/archive/2011/03/31/2001565.html

 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。

SocketServer类，服务器实现：

package learn.test;

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 {

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();
}
}
}
}

SocketClient类，客户端实现：
public class SocketClient {
static Socket client;

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 {

}
}

 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 class TestSocketServer {
public static void main(String[] argvs) {
SocketServer server = new SocketServer(12345);
server.beginListen();
}
}
再运行TestSocketClient类：
public class TestSocketClient {
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();

}
}


输出结果如下：

服务端：

Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei1
Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei1111
Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei11111111
Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei11111111111111111

客户端：
nimei1
nimei1111
nimei11111111
nimei11111111111111111