servletuteacher.java

在线教育平台： 从小学

package edu;

import java.io.IOException;
import java.sql.SQLException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class Servletuteacher extends javax.servlet.http.HttpServlet implements
		javax.servlet.Servlet {
	public void doGet(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {
		int id = 0;
		HttpSession session = req.getSession(true);
		int success = 0;
		String action = null;
		action = req.getParameter("action");
		try {
			id = Integer.valueOf(req.getParameter("id")).intValue();
		} catch (NumberFormatException e) {
		}
		UteacherBean teacher = null;
		// String message = "";
		String sort = null;
		try {
			sort = session.getAttribute("sort").toString();
		} catch (NullPointerException e) {
		}
		if (sort.equals("admin")) {
			if ("new".equalsIgnoreCase(action)) {
				teacher = doNew(req, res);

				sendBean(req, res, teacher, "/ok_ad.jsp");
			}
			if ("update".equalsIgnoreCase(action)) {
				try {
					teacher = doUpdate(req, res, id);

					sendBean(req, res, teacher, "/getuteacher.jsp");
				} catch (SQLException e) {
				}
			}

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

				try {
					success = doDelete(id);
				} catch (SQLException e) {
				}

				if (success != 1) {
					doError(req, res, "删除失败. Rows affected: " + success);
				} else {
					res.sendRedirect("getuteacher.jsp");
				}

			}
		} else
			doError(req, res, "你无权操作，或你还没有登陆！");
	}

	public UteacherBean doNew(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {
		UteacherBean teacher = new UteacherBean();
		int t_id = 0;

		try {
			t_id = Integer.valueOf(req.getParameter("t_id")).intValue();
		} catch (NumberFormatException e) {
		}
		String about = new String(req.getParameter("about").getBytes(
				"ISO8859_1"));
		if (isTrue(req, res, about) && !hasLogin(req, res, t_id)) {
			teacher.setT_id(t_id);
			teacher.setAbout(about);
			teacher.addTeacher();
		}
		return teacher;
	}

	public UteacherBean doUpdate(HttpServletRequest req,
			HttpServletResponse res, int id) throws ServletException,
			IOException, SQLException {
		UteacherBean teacher = new UteacherBean();
		String about = new String(req.getParameter("about").getBytes(
				"ISO8859_1"));

		if (isTrue(req, res, about)) {
			teacher.setId(id);
			teacher.setAbout(about);
			teacher.updateTeacher();
		}
		return teacher;
	}

	public int doDelete(int id) throws SQLException {
		int num = 0;
		UteacherBean teacher = new UteacherBean();
		num = teacher.deleteTeacher(id);
		return num;
	}

	public void sendBean(HttpServletRequest req, HttpServletResponse res,
			UteacherBean teacher, String target) throws ServletException,
			IOException {
		req.setAttribute("teacher", teacher);
		try {
			RequestDispatcher rd = req.getRequestDispatcher(target);
			rd.forward(req, res);
		} catch (Throwable t) {
		}
	}

	public void doError(HttpServletRequest req, HttpServletResponse res,
			String str) throws ServletException, IOException {
		req.setAttribute("problem", str);
		try {
			RequestDispatcher rd = req
					.getRequestDispatcher("/errorpage_ad.jsp");
			rd.forward(req, res);
		} catch (Throwable t) {

		}
	}

	public boolean isTrue(HttpServletRequest req, HttpServletResponse res,
			String about) throws ServletException, IOException {
		boolean f = true;
		String message = "";

		if (about == null || about.equals("")) {
			f = false;
			message = "简介不能为空，请重新填写！";
			doError(req, res, message);
		}
		return f;

	}

	public boolean hasLogin(HttpServletRequest req, HttpServletResponse res,
			int id) throws ServletException, IOException {
		boolean f = true;
		String message = "对不起，该帐号已经是优秀教师了,请不要重复设置!";
		TeacherBean teachers = new TeacherBean();
		f = teachers.uhasLogin(id);
		if (f == true) {
			doError(req, res, message);
		}
		return f;
	}

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

		doGet(req, res);

	}

}