InstantiationException when deploying custom portlet

[Jan Tošovský, modificado hace 7 años.]

Dear All,

what exactly I should check when getting this weird error? I checked my configuration files and there isn't anything suspicious :-(

Neither restarting the server helps (I am getting the same exception).

16:13:02,211 INFO  [localhost-startStop-4][PortletHotDeployListener:344] Registering portlets for teaforce-portlet
16:13:02,228 ERROR [localhost-startStop-4][HotDeployImpl:230] com.liferay.portal.kernel.deploy.hot.HotDeployException: Error registering portlets for teaforce-portletteaforce-portlet
com.liferay.portal.kernel.deploy.hot.HotDeployException: Error registering portlets for teaforce-portletteaforce-portlet
        at com.liferay.portal.kernel.deploy.hot.BaseHotDeployListener.throwHotDeployException(BaseHotDeployListener.java:46)
        at com.liferay.portal.deploy.hot.PortletHotDeployListener.invokeDeploy(PortletHotDeployListener.java:128)
        at com.liferay.portal.deploy.hot.HotDeployImpl.doFireDeployEvent(HotDeployImpl.java:227)
        at com.liferay.portal.deploy.hot.HotDeployImpl.fireDeployEvent(HotDeployImpl.java:96)
        at com.liferay.portal.kernel.deploy.hot.HotDeployUtil.fireDeployEvent(HotDeployUtil.java:28)
        at com.liferay.portal.kernel.servlet.PluginContextListener.fireDeployEvent(PluginContextListener.java:164)
        at com.liferay.portal.kernel.servlet.PluginContextListener.doPortalInit(PluginContextListener.java:154)
        at com.liferay.portal.kernel.util.BasePortalLifecycle.portalInit(BasePortalLifecycle.java:44)
        at com.liferay.portal.kernel.util.PortalLifecycleUtil.register(PortalLifecycleUtil.java:74)
        at com.liferay.portal.kernel.util.PortalLifecycleUtil.register(PortalLifecycleUtil.java:58)
        at com.liferay.portal.kernel.util.BasePortalLifecycle.registerPortalLifecycle(BasePortalLifecycle.java:54)
        at com.liferay.portal.kernel.servlet.PluginContextListener.contextInitialized(PluginContextListener.java:116)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4939)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
        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.deployDirectory(HostConfig.java:1113)
        at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1671)
        at java.util.concurrent.Executors$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:745)
Caused by: java.lang.InstantiationException
        at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:48)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
        at java.lang.Class.newInstance(Class.java:383)
        at com.liferay.portlet.PortletBagFactory.getPortletInstance(PortletBagFactory.java:418)
        at com.liferay.portlet.PortletBagFactory.create(PortletBagFactory.java:121)
        at com.liferay.portal.deploy.hot.PortletHotDeployListener.doInvokeDeploy(PortletHotDeployListener.java:370)
        at com.liferay.portal.deploy.hot.PortletHotDeployListener.invokeDeploy(PortletHotDeployListener.java:125)
        ... 23 more

[Jan Tošovský, modificado hace 7 años.]

I've finally found problem in my portlet class, see the 'abstract' keyword. I've copied the skeleton from another portlet, which was a common base for two separate ones.

public abstract class DisplayPortlet extends MVCPortlet {

When 'abstract' is removed, everything works fine.

I hope it can help somebody in future.