写了点极限测试

package com.example.limittest01;

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.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

@WebServlet("/processApprove")
public class ProcessApproveServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        // 获取表单提交的数据
        String employeeId = request.getParameter("employeeId");
        String attendanceType = request.getParameter("attendanceType");
        String approvedType = request.getParameter("approvedType");

        try {
            // 建立数据库连接
            Connection connection = DatabaseConnection.getConnection();

            // 查询是否存在符合条件的记录
            String query = "SELECT * FROM attendance WHERE JobID = ? AND AttendanceType = ? AND ApprovedType = ?";
            PreparedStatement preparedStatement = connection.prepareStatement(query);
            preparedStatement.setString(1, employeeId);
            preparedStatement.setString(2, attendanceType);
            preparedStatement.setString(3, approvedType);

            ResultSet resultSet = preparedStatement.executeQuery();

            if (resultSet.next()) {
                // 符合条件的记录存在，更新approvedType
                String updateQuery = "UPDATE attendance SET ApprovedType = ? WHERE JobID = ?";
                preparedStatement = connection.prepareStatement(updateQuery);
                preparedStatement.setInt(1, 1); // 将approvedType改为1表示批准
                preparedStatement.setString(2, employeeId);

                int rowsAffected = preparedStatement.executeUpdate();

                if (rowsAffected > 0) {
                    out.println("<h3>批准成功</h3>");
                } else {
                    out.println("<h3>批准失败</h3>");
                }
            } else {
                out.println("<h3>用户没有请假申请或用户不存在</h3>");
            }

            preparedStatement.close();
            connection.close();
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }
    }
}