java.lang.ClassNotFoundException: jakarta.servlet.http.HttpServlet : Spring MVC and Eclipse-CodePudding

I am creating a web application using Spring MVC and Eclipse IDE. Spring Version- 6.0.3
To configure the project, I followed the following steps-

Added dependencies in pom.xml-

 <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <!-- Spring MVC Dependency -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>6.0.3</version>
        </dependency>
  </dependencies>

Added Tomcat Server Runtime to the build path-
Added maven dependencies to deployment assembly-
web.xml- (in WEB-INF folder)

<web-app>
    <display-name>Spring MVC Demo</display-name>

    <!-- Configure dispatcher servlet -->
    <servlet>
        <servlet-name>dispatcherservlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherservlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <!-- / means handle all the requests from all urls -->
</web-app>

dispatcherservlet-servlet.xml (in WEB-INF folder)

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    https://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context     
    http://www.springframework.org/schema/context/spring-context.xsd"

    xmlns:p="http://springframework.org/schema/p">
<!-- Enable annotations -->
<context:component-scan base-package="spring-mvc-demo.src.main.java.controller"></context:component-scan>
    <!-- View Resolver bean -->
    <bean
        
        name="viewResolver">
        <!-- Inject two properties -->
        <!-- Location for pages is given to prefix -->
        <property name="prefix" value="/WEB-INF/views/" />
        <!-- ending of page is .jsp -->
        <property name="suffix" value=".jsp" />
        <!-- Example name /WEB-INF/views/hello.jsp (here the name hello will be 
            given by controller) -->
    </bean>

</beans>

Placed index.jsp under views folder in WEB-INF-

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="ISO-8859-1">
        <title>Home Page</title>
    </head>
    <body>
        <h1>This is home page</h1>
        <h1>Called by home controller</h1>
        <h1>fired for /</h1>
    </body>
</html>

Created HomeController.java class in src/main/java/controller

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/home")
public class HomeController {
    
    @GetMapping("/current")
    public String home() {
        //return the name of the page
        System.out.println("Hello this is home URL");
        return "index";
    }
}

I have created a controller with the url /home/current. On visiting this url I expect to see the desired index.jsp.
Problem- When I "Run on Server" I get following error-

SEVERE: Allocate exception for servlet [dispatcherservlet]
java.lang.ClassNotFoundException: jakarta.servlet.http.HttpServlet
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1412)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1220)
    at java.base/java.lang.ClassLoader.defineClass1(Native Method)
    at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1012)
    at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:150)

Please help me to find the error in my configuration and the reason I get this error. I saw several other posts, re-checked my steps but still getting the same error- java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet

CodePudding user response：

Based on the first screenshot in your question, you're using Tomcat 9. But for Spring 6 you need a minimum of Tomcat 10. Tomcat 10 is the first to use jakarta.* namespace whereas older versions used javax.* namespace.

Spring 6 (and Spring Boot 3) is the first version to use jakarta.* namespace whereas older versions used javax.* namespace.

So you have 2 options:

Upgrade Tomcat to a minimum of 10.
Or, downgrade Spring to a maximum of 5.

Clearly, option 1 is the recommended way to go in long term.

By the way, Spring 6 requires Java 17 not Java 1.7 as seen in the first screenshot in your question.

See also: