在线急等大神求救

[x13764390223]

简单编写了一个图书馆管理系统，可是运行登录的时候总是显示连接超时求大神解答
连接服务器处的代码

Message ms=null;
	private Socket s=null;
	public ConnectServer(Message mes){
		this.ms=mes;
		try{
			s=new Socket("172.0.0.1",8888);//连接服务器,注意服务器IP地址固定
		}catch(Exception e){
			e.printStackTrace();
			}
		}
	/**
	 * 发送消息
	 */
	public void sendMessage(){//发送消息
			try{
					ObjectOutputStream oos=new ObjectOutputStream(s.getOutputStream());
					oos.writeObject(ms);
					oos.flush();
			}catch(Exception e){
					e.printStackTrace();
			}
		}

登录处的代码

	Message mes=new Message();
				mes.setFlag(2);    //2表示要登录
				ConnectServer cs=new ConnectServer(mes);
				mes.setUserid(Integer.parseInt(itf.getText().trim()));
				mes.setuPass(String.valueOf(ptf.getPassword()).trim());
				cs.sendMessage();
				Message mes1=cs.getMessage();
				if(mes1.isOk()){
					new ClientMain(Integer.parseInt(itf.getText().trim())).setVisible(true);
					this.dispose();
				}else{
					JOptionPane.showMessageDialog(this,
			         "帐号或者密码错误！");
				}
			}

错误提示
java.net.ConnectException: Connection timed out: connect
at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.iotek.dao.impl.ConnectServer.<init>(ConnectServer.java:16)
at com.iotek.view.BookClientLogin.actionPerformed(BookClientLogin.java:104)
上面2出位置就是上面的代码求大神解答