一、需求
通过JSP、JavaBean、JDBC、Servlet技术，实现用户登录功能:
1、创建JavaBean类(实体类、数据库连接类)
2、创建数据库表操作接口及相应的操作类
3、实现登录功能的Servlet类
4、创建登录页面(能够输入学号、密码) 、登录成功页面整个项目包括(但不限于) : 2个isp页面、1个Servlet类、2个JavaBean类、1个操作接口、1个操作类
二、代码开发
1、exam264Servlet类
package com.demo; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class exam264Servlet extends HttpServlet{ public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{ doPost(request, response); } public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{ Integer userId = Integer.parseInt(request.getParameter("userId")); String pwd = request.getParameter("pwd"); exam264UserInfo userInfo = new exam264UserInfo(userId,pwd); exam264Dao dao = new exam264DaoImpl(); boolean isExist = dao.query(userInfo); if(isExist){ response.sendRedirect("success.jsp"); return; } try { request.getRequestDispatcher("/login.jsp").forward(request,response); } catch (ServletException e) { e.printStackTrace(); } } }
2、exam264UserInfo类
package com.demo; public class exam264UserInfo { private int userId; private String studentname; private String pwd; public exam264UserInfo() { } public exam264UserInfo(int userId, String pwd) { super(); this.setUserId(userId); this.pwd = pwd; } public String getStudentname() { return studentname; } public void setStudentname(String studentname) { this.studentname = studentname; } public String getPwd() { return pwd; } public void setPwd(String pwd) { this.pwd = pwd; } public int getUserId() { return userId; } public void setUserId(int userId) { this.userId = userId; } }
3、exam264DBUtil类
package com.demo; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class exam264DBUtil { // 数据库连接信息 private static final String DRIVER_CLASS = "com.mysql.jdbc.Driver"; private static final String URL = "jdbc:mysql://localhost:3306/demo"; private static final String USERNAME = "root"; private static final String PASSWORD = "root"; // 加载数据库驱动 static { try { Class.forName(DRIVER_CLASS); } catch (ClassNotFoundException e) { e.printStackTrace(); } } // 获取数据库连接 public static Connection getConnection() { Connection connection = null; try { connection = DriverManager.getConnection(URL, USERNAME, PASSWORD); } catch (SQLException e) { e.printStackTrace(); } return connection; } public static void closeResultSet(ResultSet resultSet) { try { if (resultSet != null) { resultSet.close(); } } catch (SQLException e) { e.printStackTrace(); } } public static ResultSet executeQuery(String sql,exam264UserInfo userInfo) { ResultSet res = null; Connection connection = null; PreparedStatement stat = null; try { connection = getConnection(); stat = connection.prepareStatement(sql); stat.setInt(1,userInfo.getUserId()); stat.setString(2, userInfo.getPwd()); return stat.executeQuery(); } catch (SQLException e) { e.printStackTrace(); } return res; } }
