网络编程初学者的烦恼

网络编程菜鸟的烦恼
下面是我写的简单的网络编程的代码，服务器端运行有误！哪位大侠帮忙看看是什么原因，感激！

EchoService.java:

import java.io.*;
import java.net.*;

public class EchoServer
{
private int port=8000;
private ServerSocket serverSocket;

public EchoServer()throws IOException
{
serverSocket = new ServerSocket();
System.out.println("服务器启动");
}

public String echo(String msg)
{
return "echo:"+msg;
}

private PrintWriter getWriter(Socket socket) throws IOException
{
OutputStream socketOut = socket.getOutputStream();
return new PrintWriter(socketOut,true);
}

private BufferedReader getReader(Socket socket)throws IOException
{
InputStream socketIn = socket.getInputStream();
return new BufferedReader(new InputStreamReader(socketIn));
}

public void service()
{
while(true)
{
Socket socket = null;
try 
{
socket = serverSocket.accept();
  System.out.println("New connection accepted"+socket.getInetAddress()+":"+socket.getPort());
BufferedReader br = getReader(socket);
PrintWriter pw = getWriter(socket);

String msg = null ;
while((msg=br.readLine())!=null)
{
System.out.println(msg);
pw.println(echo(msg));
if(msg.equals("bye"))
{
break;
}

}
}
catch (IOException e) 
{
e.printStackTrace();
}
finally
{
try
{
if(socket!=null)
socket.close();
}
catch (IOException e) 
{
e.printStackTrace();
}
}
}
}

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

}



EchoClient.java:

import java.net.*;
import java.io.*;
import java.util.*;

public class EchoClient
{
private String host = "localhost";
private int port = 8000;
private Socket socket;

public EchoClient() throws IOException
{
socket = new Socket(host,port);
}

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

private PrintWriter getWriter(Socket socket) throws IOException
{
OutputStream socketOut = socket.getOutputStream();
return new PrintWriter(socketOut,true);
}

private BufferedReader getReader(Socket socket) throws IOException
{
InputStream socketIn = socket.getInputStream();
return new BufferedReader(new InputStreamReader(socketIn));
}

public void talk()throws IOException
{
try 
{
BufferedReader br = getReader(socket);
PrintWriter pw = getWriter(socket);
BufferedReader localReader = new BufferedReader(new InputStreamReader(System.in));
String msg = null;

while((msg=localReader.readLine())!=null)
{
pw.println(msg);
System.out.println(br.readLine());

if(msg.equals("bye"))
{
break;
}

}
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
try 
{
socket.close();
} 
catch (IOException e) 
{
e.printStackTrace();
}
}
}
}




[解决办法]
public EchoServer()throws IOException
 {
 serverSocket = new ServerSocket();
 System.out.println("服务器启动");
 }

 改成
public EchoServer()
 {
try{
 serverSocket = new ServerSocket(port);
 System.out.println("服务器启动");

}catch(Exception e){

}
}