org.glassfish.jersey.servlet.ServletContainer

SEVERE: Servlet /JerseyDemos threw load() exceptionjava.lang.ClassNotFoundException: org.glassfish.jersey.servlet.ServletContainer    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)    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:133)    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1137)    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1081)    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5027)    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5314)    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)    at java.util.concurrent.FutureTask.run(Unknown Source)    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)    at java.lang.Thread.run(Unknown Source)

Solution – Add Jersey Library in Deployment Assembly

Open your project’s deployment assembly configuration.

Eclipse Deployment Assembly

Add Build path jar files in assembly so that they can be added to lib folder in final war file.

Deployment Assembly – Add Build Path Entries

Updated assembly will look like this.

Deployment Assembly – Updated

Now when you again run the project after building it, this will run fine and will be able to findorg.glassfish.jersey.servlet.ServletContainer class.