How To Bargain Alongside Java.Lang.Classnotfoundexception: Org.Springframework.Web.Servlet.Dispatcherservlet Inward Boundary Application

The java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet mistake comes when you lot deploy a Spring MVC application into Tomcat or Jetty as well as Servlet container non able to constitute this class, which unremarkably constitute inwards the spring-webmvc.jar file. The DispatcherServlet is the marrow of Spring MVC framework, it implements the FrontController designing as well as intercept all HTTP requests sent to your Web application as well as after road it to right controller based upon URL mapping.


You demand to declare the DispatcherServlet inwards your web.xml as well as specify the URL designing thus that Servlet container similar Tomcat should shipping or road all HTTP asking to the configured DispatcherServlet.

We convey too laid load-on-startup tag every bit 1 for this Servlet thus that it should endure loaded at the deployment time, rather than at the response fourth dimension when a telephone telephone for this Servlet comes.

In short, this DispatcherServlet is the link betwixt the Servlet Container as well as Spring MVC framework.

You tin sack farther depository fiscal establishment agree out Spring Framework 5: Beginner to Guru course on Udemy to acquire to a greater extent than nearly how Spring MVC framework plant as well as why it's amend to purpose Spring MVC framework for developing Java Web application instead of only using Servlet, JSP as well as JSF.

You tin sack encounter DispatcherServlet proclamation inwards deployment descriptor or web.xml file every bit below:

<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xmlns="http://java.sun.com/xml/ns/javaee"  xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee  http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"  id="WebApp_ID" version="3.0">   <display-name>Spring MVC HelloWorld</display-name>      <servlet>     <servlet-name>main</servlet-name>         <servlet-class>              org.springframework.web.servlet.DispatcherServlet         </servlet-class>         <load-on-startup>1</load-on-startup>    </servlet>     <servlet-mapping>         <servlet-name>main</servlet-name>         <url-pattern>/*</url-pattern>     </servlet-mapping> </web-app> 

For now, this diagram gives you lot a skillful thought of an cease to cease the menstruum of how Spring MVC handles HTTP requests as well as what is the business office of Dispatcher servlet in Spring MVC based Java application.

Cause of java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet

When you lot deploy a Java spider web application which uses Spring MVC into a spider web server similar Tomcat, it reads the deployment descriptor (web.xml file) as well as starts looking for org.springframework.web.servlet.DispatcherServlet inwards its classpath.

As per Java EE specification, all application dependency JARs must endure inwards WEB-INF/lib directory, thus if doesn't uncovering the JAR at that spot it volition throw the java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet.

If you lot are running your spider web application inwards Eclipse, you lot tin sack say Eclipse that it tin sack uncovering the Jars inwards additional place as well as non only WEB-INF/lib.

Similarly, if you lot are running spider web application inwards tomcat, it too loads JAR file from tomcat/lib, but you lot must hollo back that when you lot unload or reload a spider web app, it unloads all classes loaded from JAR file constitute inwards WEB-INF/lib but it doesn't unload classes from JAR loaded from tomcat/lib thus endure careful amongst that, every bit multiple reload may throw java.lang.OutOfMemoryError: PermGen Space inwards Tomcat.

Here is how the stacktrace of this mistake hold back like:

java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:532)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:514)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:142)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1144)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1088)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5176)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5460)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:663)
    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1642)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

The solution of java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet Error

The simplest solution of this occupation is to depository fiscal establishment agree if you lot the spring-mvc.jar inwards our classpath or not.

Depending upon the Spring MVC version similar 2.5, 3.0, 4.0 or 5.0, this degree is constitute inwards the spring-webmvc-2.5.2.jar file. Sometimes everything is too bundled inwards spring.jar, thus don't forget to depository fiscal establishment agree that.

If you lot convey the projection configured inwards Eclipse thus you lot tin sack too purpose the Eclipse shortcut Ctrl + T to uncovering out which degree file belong to which JAR file. Influenza A virus subtype H5N1 rattling useful play tricks spell troubleshooting ClassNotFoundException as well as NoClassDefFoundError inwards Java.


That's all nearly how to solve java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet Error inwards Spring based Java Application. As I said, only depository fiscal establishment agree if you lot convey spring-mvc.jar inwards your WEB-INF/lib directory or not. If no, thus only add together that JAR file as well as this mistake volition become away.


Further Reading
Spring Framework 5: Beginner to Guru
Spring Master Class - Beginner to Expert
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P.S. - If you lot desire to acquire how to prepare RESTful Web Service using Spring MVC inwards depth, I advise you lot bring together the REST amongst Spring certification class past times Eugen Paraschiv. One of the best course of didactics to acquire REST amongst Spring MVC.