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（二）登录功能实现

1. 编写前端页面

若jsp页面中文乱码：在jsp中指定页面显示的编码为GBK

添加page命令

参考：https://www.cnblogs.com/beijiguangyong/archive/2012/03/31/2437124.html

*其他所有出现编码的地方也要改掉

2. 编写login.jsp，并设置为首页

• login.jsp

  
  
  
  
  
      
  ${error}
      
  学号：
      
  密码：
      
  
  
  
  
  
  
  

• 设置为首页：

  web.xml添加

  
      login.jsp

3. 编写dao层用户登陆的接口

• StudentDao

  public interface StudentDao {
  
      //得到要登录的研究生
      public Student getLoginStudent(Connection conn,String stuNo) throws SQLException;
  }
  

4. 编写dao接口的实现层

• StudentDaoImpl

  package dao.student;
  
  import dao.BaseDao;
  import domain.Student;
  import org.junit.Test;
  
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  
  public class StudentDaoImpl implements StudentDao {
  
      @Override
      public Student getLoginStudent(Connection conn, String stuNo) throws SQLException {
          PreparedStatement ps = null;
          ResultSet rs = null;
  
          Student stu = null;
  
          if (conn != null) {
              String sql = "select * from student where stu_no=?";
              Object[] params = {stuNo};
  
  
                  rs = BaseDao.executeQuery(conn, sql, params, ps, rs);
  
  
                  if (rs.next()) {
                      stu = new Student();
  
                      stu.setStuNo(rs.getString(1));
                      stu.setPassword(rs.getString(2));
                      stu.setStuName(rs.getString(3));
                      stu.setSpecialty(rs.getString(4));
                      stu.setSex(rs.getBoolean(5));
                      stu.setBirth(rs.getDate(6));
                      stu.setPhone(rs.getString(7));
                      stu.setEmail(rs.getString(8));
                      stu.setGradSchoolCode(rs.getString(9));
                      stu.setGradSchoolName(rs.getString(10));
                      stu.setGradSpecCode(rs.getString(11));
                      stu.setGradSpecName(rs.getString(12));
                  }
                  BaseDao.closeResource(null, ps, rs);
  
          }
  
          return stu;
      }
  
  }
  

5. 业务层接口

• StudentService

  public interface StudentService {
  
      /**
       * 验证是否登录成功
       *
       * @return 登录成功则返回用户对象，无则null
       */
      public Student isLogin(String stuNo, String pwd) throws SQLException;
  }
  

6. 业务层实现类

• StudentServiceImpl

  public class StudentServiceImpl implements StudentService {
  
      private StudentDao studentDao;
  
      public StudentServiceImpl() {
          studentDao = new StudentDaoImpl();
      }
  
      /**
       * 验证是否登录成功
       *
       * @return 有登录成功则返回用户对象，无则null
       */
      @Override
      public Student isLogin(String stuNo, String pwd) {
          Connection conn = null;
          Student stu = null;
  
          try {
              conn = BaseDao.getConnection();
              stu = studentDao.getLoginStudent(conn, stuNo);
              if (stu != null) {
                  if (!pwd.equals(stu.getPassword()))
                      stu = null;
              }
          } catch (SQLException e) {
              e.printStackTrace();
          } finally {
              BaseDao.closeResource(conn, null, null);
          }
  
          return stu;
      }
  
  }
  

7. 编写Servlet

• StudentServlet

  记得添加@WebServlet注解

  @WebServlet("/studentServlet")
  public class StudentServlet extends HttpServlet {
  
      @Override
      protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
          doPost(req, resp);
      }
  
      @Override
      protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
          //获取客户端提交的数据
          String stuNo = req.getParameter("stuNo");
          String stuPwd = req.getParameter("stuPwd");
  
          try {
              StudentService studentService = new StudentServiceImpl();
              Student stu = studentService.isLogin(stuNo, stuPwd);
              if (stu != null) {    //有该用户，存进session，跳转到查看导师页面
                  HttpSession session = req.getSession();
                  session.setAttribute(Constants.STUDENT_SESSION, stu);
                  resp.sendRedirect("stu_check_tutor.jsp");
              } else {    //无该用户，跳转至登录页面，并提示错误信息
                  req.setAttribute("error", "用户名或密码不正确");
                  req.getRequestDispatcher("login.jsp").forward(req, resp);
                  System.out.println("结束Servlet....");
              }
          } catch (SQLException e) {
              e.printStackTrace();
          }
      }
  }
  

完成一个IDEA web项目（二）登录功能实现

标签：ror   ted   size   log   http   trace   OLE   domain   成功   

原文地址：https://www.cnblogs.com/musecho/p/13021568.html