ClassNotFoundException even though the jar contain

I'm configuring a new project in eclipse. my project has many modules including one of them named eas.core. to the buildPath of my eas.core module, i have added a jar file common.jcr.jar containing a class named ContentRepositorySettings, that I'm using into my codes. but on runtime, I'm still getting a ClassNotFoundException as shown below

java.lang.NoClassDefFoundError: cm/bao/common/jcr/ContentRepositorySettings
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2944)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1208)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1688)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569)
at cm.bao.eas.core.ElectronicArchivingApplicationImpl.setupGlobalSettings(ElectronicArchivingApplicationImpl.java:33)
at cm.bao.eas.core.ElectronicArchivingApplicationImpl.start(ElectronicArchivingApplicationImpl.java:49)
at cm.bao.eas.ui.gwt.server.listner.ElectronicArchivingContextListner.contextInitialized(ElectronicArchivingContextListner.java:18)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4973)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5467)
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(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:745)
Caused by: java.lang.ClassNotFoundException: cm.bao.common.jcr.ContentRepositorySettings
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1718)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569)

If your project is Faceted, right click on the project and go to Properties, and choose Deployment Assembly on the left pane. Check if the dependencies exists there as Build Path entries or Archives (jars). Once this is done you may do Project>Clean and restart the server.