简单的java socket多人聊天室

package client; import util.JDBCUtil; import java.io.*; import java.net.Socket; import java.sql.*; import java.util.Properties; import java.util.Scanner; public class Client { public static String name = null; public static int passWord ; static Socket socket = null; static BufferedReader in; static PrintWriter out; static JDBCUtil jdbcUtil; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(System.in); System.out.print("输入用户名:>"); name = sc.nextLine(); System.out.print("输入密码:>"); passWord = sc.nextInt(); jdbcUtil = new JDBCUtil(); Connection conn = jdbcUtil.getConn(); Statement stmt = conn.createStatement(); int i; while (true) { i = inspect(conn,name,passWord); //返回查询结果小于等于0，则创建对象 if(i <= 0){ setClient(stmt,name); System.out.println("创建成功"); break; }else{ System.out.println("用户已存在"); System.out.println("重新输入用户名:>"); String line = sc.nextLine(); name = sc.nextLine(); } } stmt.close(); conn.close(); try { socket = new Socket("127.0.0.1", 5678); out = new PrintWriter(socket.getOutputStream()); in = new BufferedReader(new InputStreamReader(socket.getInputStream())); Thread receive = new Thread(new receiveThread()); receive.start(); out.println(name); out.flush(); String msg; //用户发出消息 do { msg = sc.nextLine(); out.println(msg); out.flush(); } while (!"bye".equalsIgnoreCase(msg)); } catch (IOException e) { e.printStackTrace(); } } //创建用户 private static void setClient(Statement stmt, String name) throws SQLException { String sql ="Insert into work1(userName,passWord) values('"+name+"','"+passWord+"')"; stmt.execute(sql); } //查询用户是否已存在 private static int inspect(Connection conn, String name, int passWord) throws SQLException { String sql = "SELECT count(*) from work1 where userName = '"+name+"' "; PreparedStatement pst=conn.prepareStatement(sql); ResultSet i = pst.executeQuery(sql); i.next(); int l = i.getInt(1); System.out.println("查询结果为"+l); return l; } //读取服务器消息 static class receiveThread implements Runnable{ @Override public void run() { try { while (socket!=null) { String str = in.readLine(); String message = str.split("-&&-")[0]; String name = str.split("-&&-")[1]; System.out.println(name + ":>" + message); } }catch(Exception e) { e.printStackTrace(); } } } }