java socket问题，帮忙看看。收不到信息。

已经写好了服务端和客户端，大家帮忙看看为什么收不到信息。
服务端：

package com.polyphylla.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class SocketServer {
private PrintWriter pw;
private BufferedReader br;
private ServerSocket ss;
private Socket s;

public static void main(String[] args) {
new SocketServer().start();
}
public void start() {
// TODO Auto-generated method stub
try {
ss = new ServerSocket(2222);
while (true) {
s = ss.accept();
pw = new PrintWriter(s.getOutputStream(), true);
br = new BufferedReader(new InputStreamReader(s
.getInputStream()));
new Thread(new Runnable() {

public void run() {
// TODO Auto-generated method stub
String msg = "";
try {
// while(true) {
while (true) {
msg = br.readLine();
System.out.println("client:" + msg);
}
// }
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}).start();
new Thread(new Runnable() {
public void run() {
while (true) {
Scanner s = new Scanner(System.in);
String msg = s.next();
pw.print(msg);
}
}
}).start();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}
客户端：

package com.polyphylla.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

public class SocketClient {
private PrintWriter pw;
private BufferedReader br;
private Socket s;


public static void main(String[] args) {
new SocketClient().start();
}

public void start() {
// TODO Auto-generated method stub
try {
s = new Socket("127.0.0.1", 2222);
pw = new PrintWriter(s.getOutputStream(), true);
br = new BufferedReader(new InputStreamReader(s.getInputStream()));
new Thread(new Runnable() {

public void run() {
// TODO Auto-generated method stub
String msg = "";
try {
while (true) {
msg = br.readLine();
System.out.println("server:" + msg);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}).start();
new Thread(new Runnable() {
public void run() {
while (true) {
Scanner s = new Scanner(System.in);
String msg = s.next();
pw.print(msg);
}
}
}).start();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

其实这个通讯的流程你不还是不清楚。要一个写，一个读，这个过程都是单向的。就是说如果客户端先写。那么服务器就读，或者是服务器先写。客户端读。这样子才行。

我是来观望的。

把pw.print(msg); 改成pw.println(msg); 或改成pw.print(msg);pw.flush(); 就可以了

问题出在流上面 public void run() { // TODO Auto-generated method stub String msg = ""; try { while (true) { msg = br.readLine(); 客户端走到这一步就走不下去了