Question
I am in a project which uses the following relevant technologies:
In my project, I have an initialization class, which I call the ìnitService. This service is responsible for launching the main structures that the program will later on use. If it fails, the program fails.
In this initService I am trying to set up an RMI server and a client. So far, this is only the equivalent of an "helloWorld". To achieve this purpose I have an interface and an implementation class:
https://stackoverflow.com/questions/23130658
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Russianpublic interface ICommunicator extends Remote{
public boolean askNewVM() throws RemoteException;
public boolean commitingSuicide() throws RemoteException;
}
public class RMICommunicator extends UnicastRemoteObject implements ICommunicator{
private static final long serialVersionUID = 1L;
public RMICommunicator() throws RemoteException {
super();
}
@Override
public boolean askNewVM() throws RemoteException{
return false;
}
@Override
public boolean commitingSuicide() throws RemoteException{
return false;
}
}
So far so good. Then I try to compile and generate the war file using the mvn install command, which runs without problems.
The problems arise however when I deploy the generated war file into my server and try to launch it with Jetty 8.0. When I do that, the server is unable to launch due to the following error:
[ERROR][context.ContextLoader]: Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'initService': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: net/jnd/thesis/service/loadBalancer/RMICommunicator
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:135)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:394)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1448)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:384)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:283)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111)
at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:782)
at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:424)
at org.eclipse.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:774)
at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:249)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1242)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:717)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:494)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.eclipse.jetty.deploy.bindings.StandardStarter.processBinding(StandardStarter.java:39)
at org.eclipse.jetty.deploy.AppLifeCycle.runBindings(AppLifeCycle.java:186)
at org.eclipse.jetty.deploy.DeploymentManager.requestAppGoal(DeploymentManager.java:494)
at org.eclipse.jetty.deploy.DeploymentManager.addApp(DeploymentManager.java:141)
at org.eclipse.jetty.deploy.providers.ScanningAppProvider.fileAdded(ScanningAppProvider.java:145)
at org.eclipse.jetty.deploy.providers.ScanningAppProvider$1.fileAdded(ScanningAppProvider.java:56)
at org.eclipse.jetty.util.Scanner.reportAddition(Scanner.java:615)
at org.eclipse.jetty.util.Scanner.reportDifferences(Scanner.java:540)
at org.eclipse.jetty.util.Scanner.scan(Scanner.java:403)
at org.eclipse.jetty.util.Scanner.doStart(Scanner.java:337)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.eclipse.jetty.deploy.providers.ScanningAppProvider.doStart(ScanningAppProvider.java:121)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.eclipse.jetty.deploy.DeploymentManager.startAppProvider(DeploymentManager.java:555)
at org.eclipse.jetty.deploy.DeploymentManager.doStart(DeploymentManager.java:230)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.eclipse.jetty.util.component.AggregateLifeCycle.doStart(AggregateLifeCycle.java:81)
at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:58)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:96)
at org.eclipse.jetty.server.Server.doStart(Server.java:282)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.eclipse.jetty.xml.XmlConfiguration$1.run(XmlConfiguration.java:1274)
at java.security.AccessController.doPrivileged(Native Method)
at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1197)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.eclipse.jetty.start.Main.invokeMain(Main.java:473)
at org.eclipse.jetty.start.Main.start(Main.java:615)
at org.eclipse.jetty.start.Main.main(Main.java:96)
Caused by: java.lang.NoClassDefFoundError: net/jnd/thesis/service/loadBalancer/RMICommunicator
at net.jnd.thesis.service.loadBalancer.VMManager.<init>(VMManager.java:83)
at net.jnd.thesis.service.loadBalancer.VMManager.getInstance(VMManager.java:104)
at net.jnd.thesis.service.loadBalancer.LoadBalancerService.start(LoadBalancerService.java:50)
at net.jnd.thesis.service.InitializationService.start(InitializationService.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:346)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:299)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:132)
... 53 more
Caused by: java.lang.ClassNotFoundException: net.jnd.thesis.service.loadBalancer.RMICommunicator
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:430)
at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:383)
... 64 more
I have researched this forum for similar problems, but without success. However, I did find this article on the problem:
And by reading it, I believe (though I might be wrong), that my problem is the one described in step 12:
12) Java program can also throw java.lang.NoClassDefFoundError during linking which occurs during class loading in Java. One of the example of this scenario is just delete the User class from our static initializer failure example after compilation and they try to run the program. This time you will get java.lang.NoClassDefFoundError directly without java.lang.ExceptionInInitializerError and message for NoClassDefFoundError is also just printing name of class as testing/User i.e. User class from testing package. Watch out for this carefully as here root cause is absent of User.class file.
Read more: http://javarevisited.blogspot.com/2011/06/noclassdeffounderror-exception-in.html#ixzz2z8cNlxZ9
I do not believe I have any jars missing, so I think this is a guess just as good as any other.How do I fix my problem?
Solution 2
The problem was an access problem. Turns out that the security.policy file for RMI was not being read correctly (was not being found at all) and so instead of getting a FileNotFoundException, I was somehow getting a ClassNotDefException.
Permissions man ... they're hell.
OTHER TIPS
First rename your *.war to *.zip and have a look if the compiled class exists.
Else, try a maven > update in your IDE, and make sure maven dependencies are added to the classpath. I sometime get these NoClassDev errors and after update and classpath check everything works fine again.
