loginservlet.java

分为经理和出纳2个权限

package com.yiboit.cfss.login;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginServlet extends HttpServlet {

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String username = request.getParameter("username");
		String password = request.getParameter("password");
		
		String errmsg = "";
		// 服务器端验证
		if(username == null || "".equals(username)) {
			errmsg = "User name is required.\n";
		}
		
		if (password == null || "".equals(password)) {
			errmsg += "Password is required.\n";
		}
		
		if (username != null && username.length() > 30) {
			errmsg += "User name is too long.\n";
		}
		
		if (password != null && password.length() > 30) {
			errmsg += "Password is too long.\n";
		}
		
		HttpSession session = request.getSession(true);
		
		if (!"".equals(errmsg)) {
			session.setAttribute("errmsg", errmsg);
			response.sendRedirect("index.jsp");
			return;
		}
		
		LoginDAO dao = new LoginDAO();
		
		try {
			ShopUser user = dao.getShopUserById(username, password);
			if (user == null) {
				// 用户名或密码错误
				session.setAttribute("errmsg", "User name or password is invalid.");
				response.sendRedirect("index.jsp");
			} else {
				// 登陆成功
				String flag = user.getFlag();
				
				session.setAttribute("logonUsername", username);
				session.setAttribute("logonPassword", password);
				session.setAttribute("logonFlag", flag);
				
				response.sendRedirect(flag + "/description.jsp");
			}
		} catch (Exception e) {
			// 系统错误
			e.printStackTrace();
			response.sendRedirect(request.getContextPath() + "/error.jsp");
		}
		
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		this.doGet(request, response);
	}

}