Question

我在一个学校项目上有问题，这是一个小型的网络动态项目。在“登录”页面中，如果我提交数据库中存在的用户参数，一切顺利，并且我有“ success.html”页面，但是，如果我提交不在数据库中的用户参数，我将得到404页，而我希望输入“ failure.html”。您能帮我找到错误吗？

我正在使用：

Eclipse Java Neon
Tomcat 9.0.12

这是我的登录表格：

<form id="login" class="form-horizontal" action="/IROPLAS/Controller/LoginServlet" method="GET">
            <div class="form-group">
                <label class="control-label col-xs-8 col-sm-4 col-md-5" for="mail">E-mail:</label>
                <div class="col-xs-10 col-sm-8 col-md-4">
                    <input type="text" class="form-control" id="mail" name="mail" placeholder="E-mail">
                </div>
            </div>
            <div class="form-group">
                <label class="control-label col-xs-8 col-sm-4 col-md-5" for="pw">Password:</label>
                <div class="col-xs-10 col-sm-8 col-md-4">
                    <input type="password" class="form-control" id="pw" name="pw" placeholder="Password">
                </div>
            </div>
            <br>
            <button type="submit" class="btn btn-default"id="entra">Entra</button>
        </form>

这是我的Servlet：

    package Controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.logging.Logger;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/IROPLAS/Controller/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public LoginServlet() {
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.getWriter().append("Served at: ").append(request.getContextPath());
        response.setContentType("text/html");

        RequestDispatcher requestDispatcher; 
         String m=request.getParameter("mail");  
         String p=request.getParameter("pw");  

         if(Model.BUtente.validate(m, p)){
             Model.BUtente u=Model.BUtente.getUtente(m, p);          
             request.setAttribute("utente", u);
             requestDispatcher=request.getRequestDispatcher("/Success.html");
             requestDispatcher.forward(request, response);
         } //pagina profilo utente
         else{       
             PrintWriter pw=response.getWriter();
             response.sendRedirect(request.getContextPath()+"/Failure.html");            
             pw.close();
         }//errore


    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }
}

Model.BUtente.validate（mail，pw）如果用户（使用电子邮件=邮件和密码= pw）是我的数据库的记录，则返回true，否则返回false，进行了测试，效果很好。

这些是我的Success.html

    <!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
Success
</body>
</html>

和我的Failure.html

<!DOCTYPE html>

    <html>
    <head>
    <meta charset="ISO-8859-1">
    <title>Insert title here</title>
    </head>
    <body>
    Fail
    </body>
    </html>

Answer 1

我做到了！如果您遇到相同的问题，我将在此处发布我的解决方案：

我的登录表单：

<form id="login" class="form-horizontal" action="LoginServlet" method="GET">
                <div class="form-group">
                    <label class="control-label col-xs-8 col-sm-4 col-md-5" for="mail">E-mail:</label>
                    <div class="col-xs-10 col-sm-8 col-md-4">
                        <input type="text" class="form-control" id="mail" name="mail" placeholder="E-mail">
                    </div>
                </div>
                <div class="form-group">
                    <label class="control-label col-xs-8 col-sm-4 col-md-5" for="pw">Password:</label>
                    <div class="col-xs-10 col-sm-8 col-md-4">
                        <input type="password" class="form-control" id="pw" name="pw" placeholder="Password">
                    </div>
                </div>
                <br>
                <button type="submit" class="btn btn-default"id="entra">Entra</button>
            </form>

我的Servlet：

package Controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.logging.Logger;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class LoginServlet
 */
//@WebServlet("/IROPLAS/Controller/LoginServlet")
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public LoginServlet() {
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.getWriter().append("Served at: ").append(request.getContextPath());
        response.setContentType("text/html");

        RequestDispatcher requestDispatcher; 
         String m=request.getParameter("mail");  
         String p=request.getParameter("pw");  

         if(Model.BUtente.validate(m, p)){
             Model.BUtente u=Model.BUtente.getUtente(m, p);          
             request.setAttribute("utente", u);
             requestDispatcher=request.getRequestDispatcher("/Success.html");
             requestDispatcher.forward(request, response);
         } //pagina profilo utente
         else{       //404 not found
             PrintWriter pw=response.getWriter();
             response.sendRedirect("Failure.html");          
             pw.close();
         }//errore


    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

从servlet重定向到html时出现404错误

1 个答案: