Question

java 编写网络客户/服务器程序，实现如下功能： （1）设计服务器程序，运行时等待客户端连接； （2）客户

（2）客户端在启动时与服务器建立连接；
（3）客户端发送消息，服务器收到该消息后，将其中的所有小写字符转换为大写字符，发回给客户端；
（4）客户端收到服务器发回的消息后，在界面上显示。
新手木有悬赏分，跪求了！！！！

Answer 1

Server:
package s;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
　　public class Server {
public static void main(String[] args) throws IOException {
ServerSocket server = new ServerSocket(10001);
while (true) {
Socket socket = server.accept();
System.out.println("a socket in");
new UpderDeal(socket).start();
}
}
}
class UpderDeal extends Thread {
private Socket s = null;
public UpderDeal(Socket s) {
this.s = s;
}
public void run() {
byte[] b = new byte[1024];
String msg = null;
int len = 0;
try {
while (true) {
len = s.getInputStream().read(b);
msg = new String(b, 0, len);
msg = msg.toUpperCase();
s.getOutputStream().write(msg.getBytes());
}
　　} catch (IOException e) {
e.printStackTrace();
}
}
}

　　Client:
package c;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
public class Client {
public static void main(String[] args) throws UnknownHostException,
IOException {
Socket socket = new Socket("localhost", 10001);
OutputStream out = socket.getOutputStream();
InputStream in = socket.getInputStream();
String msg = null;
Scanner sc = new Scanner(System.in);
new Recieve(in).start();
　　while (true) {
msg = sc.next();
if (msg.equals("exit")) {
break;
}
System.out.println("发出的信息：" + msg);
out.write(msg.getBytes());
　　}
}
}
class Recieve extends Thread {
private InputStream in = null;
　　public Recieve(InputStream in) {
this.in = in;
}
public void run() {
byte[] b = new byte[1024];
int len = 0;
while (true) {
try {
len = in.read(b);
System.out.println("收到的信息为：" + new String(b, 0, len));
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

希望可以帮到你，还有一种异步用SocketChannel的，我也怎么用过，可以网上参考一下。　　

Answer 2

不就是一个socket编程吗。。