studentloginsvlt.java

一个学生课绩管理系统

package control;

import java.io.*;
import java.sql.ResultSet;
import java.sql.*;
import database.checkEnrol;
import database.sqlBean;
import javax.servlet.*;
import javax.servlet.http.*;

public class StudentLoginSvlt extends HttpServlet {
	public void doGet(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {

		String stu_id = req.getParameter("id");
		String cour_id = req.getParameter("cour_id");
		String class_id = req.getParameter("class_id");
		String prepare = req.getParameter("prepare");
		String pw1 = null;
		String pw2 = null;
		String e_mail = null;
		String tel = null;
		String action = req.getParameter("action");

		ResultSet rs = null;

		if ("update".equalsIgnoreCase(action)) {

			stu_id = req.getParameter("id");
			pw1 = req.getParameter("password1");
			pw2 = req.getParameter("password2");
			if (pw1.equals("") || pw2.equals("") || pw1 == null || pw2 == null)
				doError(req, res, "密码不能为空！");
			e_mail = req.getParameter("e_mail");
			tel = req.getParameter("tel");
			doUpdate(req, res, pw1, pw2, e_mail, tel, stu_id);
			res.sendRedirect("/test/student.jsp");
		}

		if ("checkmark".equalsIgnoreCase(action)) {
			rs = getScore(stu_id);
			sendResultSet(req, res, rs, "/checkmark.jsp");
		}

		if ("enrol".equalsIgnoreCase(action)) {

			doEnrol(req, res, stu_id, cour_id, class_id, prepare);
			res.sendRedirect("/test/DisplayCourse.jsp");
		}
	}

	public void doEnrol(HttpServletRequest req, HttpServletResponse res,
			String stu_id, String cour_id, String class_id, String prepare)
			throws ServletException, IOException {
		int num = 0;
		checkEnrol check = new checkEnrol();

		if (prepare.equals("0")) {
			num = check.enrol(class_id, stu_id);
		} else {
			if (check.hasPassPrepare(prepare)) {
				num = check.enrol(class_id, stu_id);
			} else
				doError(req, res, "请先完成预修课");
		}

		if (num == 0) {
			doError(req, res, "注册课程失败！！");
		}

	}

	public void doUpdate(HttpServletRequest req, HttpServletResponse res,
			String pw1, String pw2, String e_mail, String tel, String id)
			throws ServletException, IOException {
		int num = 0;
		if (!pw1.equals(pw2))
			doError(req, res, "密码不一致，请重输！");
		checkEnrol check = new checkEnrol();
		sqlBean db = new sqlBean();
		num = check.updatestu(pw1, id, e_mail, tel);
		if (num == 0)
			doError(req, res, "更新失败");
	}

	public ResultSet getScore(String stu_id) {
		String sql = "select enrol.score , course.name ,course.mark "
				+ "from enrol ,course ,classes " + "where stu_id='" + stu_id
				+ "' " + "and enrol.class_id=classes.id "
				+ "and classes.cour_id=course.id ";
		sqlBean db = new sqlBean();
		ResultSet rs = db.executeQuery(sql);
		return rs;
	}

	public void doError(HttpServletRequest req, HttpServletResponse res,
			String str) throws ServletException, IOException {

		req.setAttribute("problem", str);
		RequestDispatcher rd = getServletContext().getRequestDispatcher(
				"/errorpage.jsp");
		rd.forward(req, res);
	}

	public void sendResultSet(HttpServletRequest req, HttpServletResponse res,
			java.sql.ResultSet rs, String target) throws ServletException,
			IOException {
		req.setAttribute("rs", rs);
		RequestDispatcher rd = getServletContext().getRequestDispatcher(target);
		rd.forward(req, res);
	}

	public void doPost(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {
		doGet(req, res);
	}

}