这里是12.16随笔
代码留档：package come;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
@WebServlet("/DengluServlet")
public class DengluServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {String name = request.getParameter("Name");String role = request.getParameter("role");String password = request.getParameter("password");try {// 加载数据库驱动（根据你的MySQL版本可能需要调整）Class.forName("com.mysql.cj.jdbc.Driver");// 建立数据库连接Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/ygkaoqin", "root", "12345");String sql = "SELECT * FROM xinxi WHERE Name =? AND role =? AND password =?";PreparedStatement preparedStatement = connection.prepareStatement(sql);preparedStatement.setString(1, name);preparedStatement.setString(2, role);preparedStatement.setString(3, password);ResultSet resultSet = preparedStatement.executeQuery();if (resultSet.next()) {if ("员工".equals(role)) {response.sendRedirect("EmployeeFunction.jsp");} else if ("部门经理".equals(role)) {response.sendRedirect("ManagerFunction.jsp");} else if ("管理员".equals(role)) {response.sendRedirect("AdminFunction.jsp");}} else {response.sendRedirect("index.jsp?error=1");// 登录失败，返回登录页面并可以显示错误信息}resultSet.close();preparedStatement.close();connection.close();} catch (ClassNotFoundException | SQLException e) {e.printStackTrace();}
}
}
一个登录的逻辑
