1
我已經構建了一個帶有兩個jsp文件和控制器的小型servlet。Servlet getServletContext（）。getRequestDispatcher顯示url行中的屬性
這是login.jsp：
<body>
<section class="loginform cf">
<form name="login" action="controller/login" method="get" onsubmit="return validateForm()"
accept-charset="utf-8">
<ul>
<li><label for="username">Username</label> <input type="text"
name="username" ></li>
<li><label for="password">Password</label> <input
type="password" name="password" ></li>
<li><input type="submit" value="Login"></li>
</ul>
</form>
<form action="http://localhost:8080/ToDoListProj" method="get">
<input title="Register" type="submit" value="Not Yet A Member?" formaction="register.jsp"/>
<br/>
</form>
</section>
</body>
，這是控制器：
package il.ac.hit.controller;
import il.ac.hit.model.HibernateToDoListDAO;
import il.ac.hit.model.Item;
import il.ac.hit.model.ToDoListPlatformException;
import il.ac.hit.model.User;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import antlr.StringUtils;
/**
* Servlet implementation class ToDoListPlatformContrller
*/
@WebServlet("/controller/*")
public class ToDoListPlatformController extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public ToDoListPlatformController() {
super();
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
private boolean isAlphaNumeric(String word)
{
return word.matches("[a-zA-Z0-9]+");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String path = request.getPathInfo();
System.out.println(path);
RequestDispatcher dispatcher = null;
switch(path)
{
case "/login":
{
try {
String username = request.getParameter("username");
String password = request.getParameter("password");
if(username != null && password != null && isAlphaNumeric(username) && isAlphaNumeric(password))
{
List<User> usersList = il.ac.hit.model.HibernateToDoListDAO.getInstance().getUsersList();
for(User user : usersList)
{
if(user.getName().equals(username) && user.getPassword().equals(password))
{
Cookie cookie = new Cookie("UserId", username);
cookie.setPath("/");
response.addCookie(cookie);
request.getSession().setAttribute("UserID", username);
request.getSession().setAttribute("table", HibernateToDoListDAO.getInstance().getItemsList(username));
dispatcher = getServletContext().getRequestDispatcher("/view.jsp");
break;
}
}
}
else
{
dispatcher = getServletContext().getRequestDispatcher("/wronglogin.jsp");
}
} catch (ToDoListPlatformException e) {
dispatcher = getServletContext().getRequestDispatcher("/wronglogin.jsp");
}
break;
}
dispatcher.forward(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
，正在所示的兩種屬性在URL行中。
這就是我得到：
http://localhost:8080/ToDoListProj/controller/login?username=usernamesample&password=passwordasmple
我該如何解決呢？
謝謝，它工作。 現在我有另一個概率。 登錄後，servlet將url轉發給view.jsp巫婆是項目的視圖。 有一個「添加項目」按鈕。 我添加一個項目後，它會返回到視圖頁面並顯示在列表中。 但如果我點擊'刷新'項目再次被添加。 – Dan
@Dan刷新再次觸發「添加項目」動作。有一種模式可以解決這個問題，請參閱https://en.wikipedia.org/wiki/Post/Redirect/Get。 – wero