javaweb+mysql数据库实现注册登录程序

package com.java.jsp.servlet; import java.io.IOException; import java.sql.SQLException; import java.util.*; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.java.japdao.UserDao; import com.java.japdao.Impl.UserDaoImpl; import com.java.jsp.User; public class UserLoginServlet extends HttpServlet { private static final long serialVersionUID = -205347041340147008L; int logintime = 0; static int time; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { User user = new User(); // 获取login.jsp页面提交的账号和密码 String name = request.getParameter("name"); String password = request.getParameter("password"); // 测试数据 System.out.println(name + " " + password); // 获取login.jsp页面提交的账号和密码设置到实体类User中 user.setName(name); user.setPassword(password); // 引入数据交互层 UserDao dao = new UserDaoImpl(); User us; try { us = dao.login(user); // 测试返回的值 System.out.println(us); if (us.getId()==(404)) { logintime+=1; System.out.println(logintime); if(logintime==1) { Date date = new Date(); //取时间 time = date.getDate()+1; System.out.println("解锁时间："+time+"号"); } if(logintime>=5) { Date Now = new Date(); //取时间 Calendar calendars = new GregorianCalendar(); calendars.setTime(Now); calendars.add(calendars.HOUR,0); Now=calendars.getTime(); System.out.println("当前时间："+Now.getDate()+"号"); System.out.println("解锁时间："+time+"号"); response.sendRedirect("loginlock.jsp"); if(Now.getMinutes()>=time) { logintime=0; } return;//在sendRedirect后要接return，否则报错 } response.sendRedirect("loginfailed.jsp"); } if (us.getName().equals(name) && us.getPassword().equals(password)) { if(logintime>=3) { response.sendRedirect("loginlock.jsp");return;} response.sendRedirect("loginsuccess.jsp"); System.out.println("usn:"+us.getName()+"name:"+name+"usp:"+us.getPassword()+"psw："+password); } /* * if (us != null) { response.sendRedirect("loginsuccess.jsp"); * request.setAttribute("info", "登陆成功"); } */ else { response.sendRedirect("loginfailed.jsp"); /* request.setAttribute("info", "登录失败"); */ } /* * request.getRequestDispatcher("/index/info.jsp").forward(request, * response); */ } catch (NullPointerException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } } }