loginservlet.java

java bean 登陆 界面。。。。。。很实用

package com.wanczy.servlet;

import java.io.IOException;

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

import com.wanczy.test.User;
import com.wanczy.test.UserDao;

public class LoginServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public LoginServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * 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 {
		response.setCharacterEncoding("gbk");
		request.setCharacterEncoding("gbk");
		response.setContentType("text/html");
		User user = (User) request.getAttribute("user1");
		UserDao dao = new UserDao();
		User username = dao.getUser(user.getName());
		String error = null;
		String url;
		if (username == null) {
			error = "user" + user.getName() + "不存在";
			url = "/index.jsp";
		} else {
			if (username.getPass().equals(user.getPass())) {
				url = "/success.jsp";
				HttpSession session = request.getSession();
				username.setLogined(true);// 这个地方
				session.setAttribute("user", username);
			} else {
				error = "失败";
				url = "/index.jsp";
			}
		}
		if (error != null) {
			request.setAttribute("error", error);
		}
		RequestDispatcher rd = getServletContext().getRequestDispatcher(url);
		rd.forward(request, response);
	}

	/**
	 * 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 {
		doGet(request, response);
	}

	/**
	 * Initialization of the servlet. <br>
	 * 
	 * @throws ServletException
	 *             if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}