loginservlet.java

简单的流言板系统,用myeclipse进行编写的,采用简单的jstl+javabean+servlet+jsp,属于三层架构.

/**
 * 
 */
package me.work.servlets;

import java.io.IOException;
import java.io.PrintWriter;

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 org.apache.catalina.Session;

import me.work.services.DBOperation;

/**
 * this servlet mainly handle the login process
 * 
 * @author Administrator
 * 
 */
public class LoginServlet extends HttpServlet {

	/**
	 * serialVersionUID
	 */
	private static final long serialVersionUID = 1L;

	/*
	 * (non-Javadoc)
	 * 
	 * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
	 *      javax.servlet.http.HttpServletResponse)
	 */
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		doPost(req, resp);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,
	 *      javax.servlet.http.HttpServletResponse)
	 */
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		
		 
		// get the submit method to just which button user clicked
		String method = req.getParameter("method");
		String userType = req.getParameter("uType");
		try {
			
			
	        
	        if ("submit".equals(method)) {

				String userName = req.getParameter("userName");
				String userPassword = req.getParameter("userPassword");
				HttpSession session = req.getSession();
				// do submit action
				DBOperation dbo = new DBOperation();
				if ("Admin".equals(userType.trim())) {
					req.setAttribute("role", "Admin");
				}
				// test user's name and password
				if (dbo.userLogin(userType, userName, userPassword)) {
					session.setAttribute("userName", userName);
					// redirect to user's page
					req.getRequestDispatcher("./pages/userControl.jsp")
							.forward(req, resp);
					return;
				} else {
					// if the user failed login
					req.setAttribute("uType", userType);
					req
							.setAttribute("error",
									"Please make sure you input the correct information");
					req.getRequestDispatcher("./pages/index.jsp").forward(req,
							resp);
					return;
				}

				// do register action
			} else {
				if ("Admin".equals(userType)) {
					// you can't register a Admin
					// set the error message
					req.setAttribute("error", "You can't register as an Admin");
					// forward to register page to show the error to user
					req.getRequestDispatcher("./pages/index.jsp").forward(req,
							resp);
				} else {
					req.getRequestDispatcher("./pages/register.jsp").forward(
							req, resp);
				}
			}
	        
	        
			

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}