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I'm having a problem with my first Web Application. I use IntelliJ as IDE and Tomcat as Webserver. Every servlet I've tried to acces, throws an 404 Error. Even if I copy some youtube tutorials, which seems to work like a charm.
The button in the form sends me to: http://localhost:8080/IUBHQuiz/login
Can you tell me whats wrong? I am going nuts.
login.java
package com.example.IUBHQuiz;
import java.io.*;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.sql.*;
@WebServlet("/login")
public class login extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String email = request.getParameter("fmail");
String pass = request.getParameter("fpw");
if(email.equals("j") && pass.equals("j"))
{
RequestDispatcher rs = request.getRequestDispatcher("/main.jsp");
rs.forward(request, response);
}
else
{
out.println("Username or Password incorrect");
RequestDispatcher rs = request.getRequestDispatcher("/index.jsp");
rs.include(request, response);
}
out.close();
}
index.jsp
<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
<title>IUBH Quiz</title>
<link href="./resources/css/style.css" rel="stylesheet">
</head>
<body>
<div class="main">
<div class="image-container">
<img src="./resources/images/logo.png" alt="Logo">
</div>
<div class="Login">
<h1>Willkommen beim IUBH-Quiz!</h1>
<form action="login" method="post">
E-Mail:<input type="text" id="fmail" name="fmail"><br><br>
Passwort: <input type="password" id="fpw" name="fpw"><br><br>
<input type="submit" value="Log In" class="button">
</form>
</div>
<div class="Links">
<a href="#">Passwort vergessen</a>
<a href="#">Registrieren</a>
</div>
</div>
</body>
</html>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
</web-app>
870
This error indicates that the server could not find the desired resource. This resource can be any file such as JSP, HTML, or image resource. Usually, the resource is present, but it is referenced incorrectly. In most cases, you can fix this by correcting the URL.
Show More. Apache Tomcat is a long-lived, open source Java servlet container that implements core Java enterprise (now Jakarta EE) specifications, including the Jakarta Servlet, Jakarta Server Pages, and Jakarta WebSocket specs.
Your servlet is actually extending from javax.servlet.Servlet which in turn is part of an older JEE version which is actually not supported by your target runtime (Tomcat 10.x). Replace the javax.servlet.* imports in your code by jakarta.servlet.* ones. import jakarta.servlet.*; import jakarta.servlet.http.*;
So by default, the default servlet is loaded at webapp startup and directory listings are disabled and debugging is turned off. If you need to change the DefaultServlet settings for an application you can override the default configuration by re-defining the DefaultServlet in /WEB-INF/web.xml.
You can work-around this problem by using the Tomcat specific /WEB-INF/tomcat-web.xml deployment descriptor. The format is identical to /WEB-INF/web.xml. It will override any default settings but not those in /WEB-INF/web.xml. Since it is Tomcat specific, it will only be processed when the application is deployed on Tomcat. What can I change?
The jakarta.servlet.Servlet is part of Servlet API version 5.0 which in turn is part of Jakarta EE version 9. Your servlet is actually extending from javax.servlet.Servlet which in turn is part of an older JEE version which is actually not supported by your target runtime (Tomcat 10.x). You have 2 options:
For copyright reasons the Servlet 5.0 API (implemented by Tomcat 10) and the Servlet 4.0 API (implemented by Tomcat 9) are incompatible: the API namespace changed from javax.* to jakarta.*. This can manifest in many ways:
web.xml descriptor throw a lot of ClassNotFoundExceptions and don't start: cf. Tomcat 10.x throws java.lang.NoClassDefFoundError on javax/servlet/ServletRequestListener.web.xml descriptor log a "X is not a jakarta.servlet.Servlet" error: cf. Servlet class org.restlet.ext.servlet.ServerServlet is not a jakarta.servlet.Servlet.ServletContainerInitializer (like Spring and Spring Boot applications) don't start: cf. Deploying Spring MVC 5 on Tomcat 10 … deployment problems
The last one is the hardest to diagnose: no errors are written to the log files, but the application doesn't work. The reason behind this behavior is that @javax.servlet.WebServlet annotations are ignored: the server is scanning for @jakarta.servlet.WebServlet.
Since all three problems have the same cause, the solutions provided to the aforementioned questions all work. In this specific case I would advise to use the Tomcat Migration Tool for Jakarta EE.
Remark: The Tomcat download site features a warning, that unfortunately many people don't notice:
Users of Tomcat 10 onwards should be aware that, as a result of the move from Java EE to Jakarta EE as part of the transfer of Java EE to the Eclipse Foundation, the primary package for all implemented APIs has changed from javax.* to jakarta.*. This will almost certainly require code changes to enable applications to migrate from Tomcat 9 and earlier to Tomcat 10 and later.
125
I had the same issue while reproducing the problem reported at IntelliJ IDEA forums.
It didn't work with Tomcat 10 for the reasons described in the answer by Piotr P. Karwasz, but it works just fine with Tomcat 9.0.44 and earlier versions.
5
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