登录页面
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编写前端页面
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设置首页（欢迎页面）
<!--设置欢迎页面--> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list> -
编写dao层 登录用户的接口
//得到要登录的用户 public User getLoginUser(Connection connection,String userCode) throws SQLException; } -
编写dao接口的实现类
public class UserDaoImpl implements UserDao{ public User getLoginUser(Connection connection, String userCode) throws SQLException { PreparedStatement pstm = null; ResultSet rs = null; User user = null; if (connection != null) { String sql="select * from smbms_user where userCode=?"; Object[] params = {userCode};//数组 rs = BaseDao.execute(connection, pstm, rs, sql, params); if(rs.next()){ user = new User(); user.setId(rs.getInt("id")); user.setUserCode(rs.getString("userCode")); user.setUserName(rs.getString("userName")); user.setUserPassword(rs.getString("userPassword")); user.setGender(rs.getInt("gender")); user.setBirthday(rs.getDate("birthday")); user.setPhone(rs.getString("phone")); user.setAddress(rs.getString("address")); user.setUserRole(rs.getInt("userRole")); user.setCreatedBy(rs.getInt("createy")); user.setCreationDate(rs.getTimestamp("creationDate")); user.setModifyBy(rs.getInt("modifyBy")); user.setModifyDate(rs.getTimestamp("modifyDate")); } BaseDao.closeResource(null,pstm,rs); } return user; } } -
业务层接口
public interface UserService { //用户登录 public User login(String userCode,String password); } -
业务层实现类
public class UserServiceImpl implements UserService{ //业务层都会调用dao层，所以我们要引入dao层 ; private UserDao userDao; public UserServiceImpl(){ userDao = new UserDaoImpl(); } public User login(String userCode, String password) { Connection connection = null; User user = null; try { connection = BaseDao.getConnection(); //通过业务层调用对应的具体的数据库操作 user = userDao.getLoginUser(connection, userCode); } catch (SQLException e) { e.printStackTrace(); }finally { BaseDao.closeResource(connection,null,null); } return user; } } -
编写Servlet
package com.well.servlet.user; import com.well.pojo.User; import com.well.service.user.UserServiceImpl; import com.well.util.Constants; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class LoginServlet extends HttpServlet { //Servlet：控制层，调用业务层代码 @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("LoginSerlet--start..."); //获取用户名和密码 String userCode = req.getParameter("userCode"); String userPassword = req.getParameter("userPassword"); //和数据库中的密码进行对比，调用业务层 UserServiceImpl userService = new UserServiceImpl(); User user = userService.login(userCode, userPassword); //这里已经把登录的人已经查出来了 if (user != null) { //查有此人，可以登录 //将用户的信息放到Session中 req.getSession().setAttribute(Constants.USER_SESSION,user); //跳转到内部主页 resp.sendRedirect("jsp/frame.jsp"); }else {//查无此人 ，无法登录 //转发会登录页面，顺便提示他，用户名或者密码错误； req.setAttribute("error","用户名或者密码不正确"); req.getRequestDispatcher("login.jsp").forward(req,resp); } } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doGet(req, resp); } } -
注册Servlet
<!--Servlet--> <servlet> <servlet-name>LoginServlet</servlet-name> <servlet-class>com.well.servlet.user.LoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/login.do</url-pattern> </servlet-mapping> -
测试访问，确保以上能成功！
登录功能优化
注销功能：
思路：移除Session，返回登录页面
public class LogoutServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//移除用户的Constants.USER_SESSION
req.getSession().removeAttribute(Constants.USER_SESSION);
resp.sendRedirect(req.getContextPath()+"/login.jsp"); //返回登录页面
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
注册xml
<!--注销-->
<servlet>
<servlet-name>LogoutServler</servlet-name>
<servlet-class>com.well.servlet.user.LogoutServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LogoutServler</servlet-name>
<url-pattern>/jsp/logout.do</url-pattern>
</servlet-mapping>
登录拦截优化
编写过滤器，并注册
package com.well.filter;
import com.well.pojo.User;
import com.well.util.Constants;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class SysFilter implements Filter {
public void init(FilterConfig filterConfig) throws ServletException {
}
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) resp;
//过滤器 从Session获取用户
User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);
if (user == null) {//已经移除或者注销，或者未登录
response.sendRedirect("/smbms/error.jsp");
}else {
chain.doFilter(req,resp);
}
}
public void destroy() {
}
}
注册过滤器
<!--用户登录过滤器-->
<filter>
<filter-name>SysFilter</filter-name>
<filter-class>com.well.filter.SysFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>SysFilter</filter-name>
<url-pattern>/jsp/*</url-pattern>
</filter-mapping>