java小程序，模拟客户端和服务端通信的，编译通过，运行时没有任何输出，求教

Question

客户端代码：
import java.io.*;
import java.net.*;
public class ClientTalk implements Runnable {
Socket s;
DataOutputStream dos;
DataInputStream dis;
InputStreamReader isr;
BufferedReader br;

public void run() {
try {
String string2 = dis.readUTF();
while(string2.equalsIgnoreCase("exit") != true) {
System.out.println("server : " + string2);
string2 = dis.readUTF();
}
dis.close();
}catch (Exception e) {

  }

}

public static void main(String []args) {
try {
Socket s = new Socket("127.0.0.1",8888);

     DataOutputStream dos = new DataOutputStream(s.getOutputStream());
     DataInputStream dis = new DataInputStream(s.getInputStream());
     InputStreamReader isr = new InputStreamReader(System.in);
     BufferedReader br = new BufferedReader(isr);

     Runnable myRunnable = new ClientTalk();
     Thread thread = new Thread(myRunnable);
     thread.start();
     String string = br.readLine();

     while(string.equalsIgnoreCase("exit") != true) {
        dos.writeUTF(string);
        string = br.readLine();
     }

     dos.close();
  }catch (Exception e) {
     e.printStackTrace();
  }

}
}

服务端代码：
import java.io.*;
import java.net.*;
public class ServerTalk implements Runnable {
ServerSocket ss;
Socket s;
DataOutputStream dos;
DataInputStream dis;
InputStreamReader isr;
BufferedReader br;

public void run() {
try {
String string2 = dis.readUTF();
while(string2.equalsIgnoreCase("exit") != true) {
System.out.println("client : " + string2);
string2 = dis.readUTF();
}
dis.close();
}catch (Exception e) {

  }

}

public static void main(String []args) {
try {
ServerSocket ss = new ServerSocket(8888);
Socket s = ss.accept();
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
DataInputStream dis = new DataInputStream(s.getInputStream());
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);

     Runnable myRunnable = new ServerTalk();
     Thread thread = new Thread(myRunnable);
     thread.start();
     String string = br.readLine();

     while(string.equalsIgnoreCase("exit") != true) {
        dos.writeUTF(string);
        string = br.readLine();
     }

     dos.close();
  }catch (Exception e) {
     e.printStackTrace();
  }

}
}

编译通过了，分别在两个命令提示符中运行客户端和服务端，在命令行中输入信息后没有任何的输出。请问这是为什么？

Answer 1

String string2 = dis.readUTF();
很明显可以看出，这一句是会抛出异常的，言尽于此，自己去打断点调试，看看是为什么吧。提示：你并没有正真实例化ClientTalk类实例的一系列IOStream属性。