java客户端登陆服务器用户名验证

 import java.io.*; import java.net.*; /* *客户端 */ class client { public static void main(String[] args) throws Exception { Socket s = new Socket("192.168.33.1",10008);//建立服务 BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in));//读取键盘输入用户名 PrintWriter pw = new PrintWriter(s.getOutputStream(),true);//读到数据往服务端写 BufferedReader bufin = new BufferedReader(new InputStreamReader(s.getInputStream()));//将客户端返回的数据读入 for(int x = 0;x <3; x ++)//只登陆3次设定 { String line = bufr.readLine();//读取用户名 pw.println(line); if(line == null)//为空用户名终止 break; pw.println(line); String info = bufin.readLine();//读取服务端返回的数据 System.out.println("Server info:"+info); if(info.contains("欢迎登陆"))//用户登录终止 break; } bufr.close(); s.close(); } } /* *服务端 */ class ServerThread implements Runnable { private Socket s; ServerThread(Socket s) { this.s = s; } public void run() { String ip = s.getInetAddress().getHostAddress(); System.out.println(ip+"...........connect"); try { for(int x = 0;x <3;x ++) { BufferedReader bufin = new BufferedReader(new InputStreamReader(s.getInputStream()));//读取客户端发送的数据 String name = bufin.readLine(); if(name == null) break; BufferedReader bufr = new BufferedReader(new FileReader("user.txt"));//读取已存入用户账户，本来是读取数据库，这里方便就写了一个文本 PrintWriter out = new PrintWriter(s.getOutputStream(),true);//写入流，服务端写出 String line = null; boolean flag = false;//判断标记 while((line = bufr.readLine())!= null)//读取数据库(Use.txt)中数据 { if(line.equals(name))//如果数据库和读取用户名相同，则终止 { flag = true; break; } } if(flag) { System.out.println(name+":已登录"); out.println(name+":欢迎登陆"); break; } else { System.out.println(name+":尝试登陆"); out.println(name+":用户名不存在"); } } s.close(); } catch (Exception e) { throw new RuntimeException("验证失败"); } } } class server { public static void main(String[] args) throws Exception { ServerSocket ss = new ServerSocket(10008);//建立服务 while (true) { Socket s = ss.accept();//接收客户端传来数据 new Thread(new ServerThread(s)).start();//开启线程 } } }