求救，关于对象流 读写的问题.
服务器端为什么接收不到客户端发送过去的数据?
找了很久也没有找到是什么原因.
所以贴出来让大家帮忙解决，谢谢了.

服务端:
import   java.io.IOException;
import   java.io.ObjectInputStream;
import   java.io.ObjectOutputStream;
import   java.net.ServerSocket;
import   java.net.Socket;
import   java.util.Vector;
public   class   Server   extends   java.lang.Thread{
ServerSocket   ss   =   null;
ObjectInputStream   ois   =   null;
public   Server()   {
try   {
ss   =   new   ServerSocket(1860);
System.out.println( "服务器已启动...! ");
}   catch   (IOException   e)   {
e.printStackTrace();
}
}
public   void   run()   {
String   type   =   null;
while   (true)   {
try   {
Socket   client   =   ss.accept();
ois   =   new   ObjectInputStream(client.getInputStream());
try   {
System.out.println(ois.readObject());
}   catch   (ClassNotFoundException   e)   {
e.printStackTrace();
}
}   catch   (IOException   e)   {
e.printStackTrace();
}
}
}
public   static   void   main(String   args[])   {
new   Server().start();
}
}


客户端:
import   java.io.IOException;
import   java.io.ObjectInputStream;
import   java.io.ObjectOutputStream;
import   java.net.Socket;
import   java.net.UnknownHostException;
public   class   Client{
public   static   void   main(String[]   args)   {
try   {
Socket   s   =   new   Socket( "127.0.0.1 ",1860);
ObjectOutputStream   oos   =   new   ObjectOutputStream(s.getOutputStream());
UserInfo   uinfo   =   new   UserInfo();
uinfo.setName( "lxh ");
uinfo.setPassword( "asdf ");
oos.writeObject(uinfo);
}   catch   (UnknownHostException   e)   {
e.printStackTrace();
}   catch   (IOException   e)   {
e.printStackTrace();
}
}
}


import   java.io.IOException;
import   java.io.ObjectInputStream;
import   java.io.ObjectOutputStream;
import   java.util.Date;
public   class   UserInfo   implements   java.io.Serializable{
private   String   name   =   null;            
private   String   password   =   null;    
public   UserInfo(){}
public   String   getName()   {
return   name;
}
public   void   setName(String   name)   {
this.name   =   name;
}
public   String   getPassword()   {
return   password;
}
public   void   setPassword(String   password)   {
this.password   =   password;
}
private   void   writeObject(ObjectOutputStream   oos){
try   {
oos.writeUTF(name);
oos.writeUTF(password);
oos.flush();
}   catch   (IOException   e)   {
e.printStackTrace();
}
}
private   void   readObject(ObjectInputStream   ois)   {
try   {
name   =   ois.readUTF();