使用线程时Java接口冻结

Question

我正在使用以下代码，我正在尝试将新用户插入数据库

if(!userText.getText().equals("") && !passwordText.getText().equals(""))
        {
        try{

        Class.forName("com.mysql.jdbc.Driver");
                    String url="jdbc:mysql://localhost:3306/Poo";
        String user="root";
        String pass="";
        Connection cn=DriverManager.getConnection(url,user,pass);
        System.out.println("connected");
        Statement st=cn.createStatement();



                    ResultSet rs=st.executeQuery("select ID,Name,Password from Users");

                    while(rs.next()){

        if (userText.getText().equals(rs.getString("Name"))
                           && passwordText.getText().equals(rs.getString("Password")))
                            {
                                System.out.println("Correct");

                                user=rs.getString("Name");
                                id=Integer.parseInt(rs.getString("ID"));

                                l2.setForeground(Color.green);
                                l2.setText("Authentication Successful"); 

                                Thread.sleep(2500);
                                break;
                            }
                    else{
                                l2.setForeground(Color.red);
                                l2.setText("Wrong Username or Password!");
                            }

                            } 


        }catch(Exception f){System.out.println(f.getMessage());}
        System.out.println(userText.getText()+" " +passwordText.getText());
    }

关于执行界面冻结，我看不到2500毫秒的“成功”，有什么想法吗？