hello,
I am new to vaadin. Right now we are working on jee project (ejb3 + vaadin).
here is the sample code
MainApp extends Application
@EJB
GreeterService service;
private void setHomeComponent() {
Label label = new Label(service.sayHello() + " vaadin user");
horizontalSplit.setSecondComponent(label);
}above code is working perfectly fine. but if i call setMainComponent(getHomeView()) from init like below and call ejb service from other class then it is giving error.
public void init() {
buildMainLayout();
setMainComponent(getListView());
}
private void setMainComponent(Component c){
horizontalSplit.setSecondComponent(c);
}
private ListView getListView() {
if (listView == null) {
listView = new ListView(this);
}
return ListView;
}
Listview extends Label
@EJB
GreeterService service;
private MainApp app;
public HomeView(final MainApp app) {
this.app = app;
addStyleName("view");
setCaption(service.sayHello() + " vaadin user");
setSizeFull();
}Error log:
com.vaadin.event.ListenerMethod$MethodException
Cause: java.lang.NullPointerException
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:510)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:162)
at com.vaadin.ui.AbstractComponent.fireEvent(AbstractComponent.java:1166)
at com.vaadin.ui.Button.fireClick(Button.java:380)
at com.vaadin.ui.Button.changeVariables(Button.java:196)
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariableBurst(AbstractCommunicationManager.java:1297)
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariables(AbstractCommunicationManager.java:1217)
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.doHandleUidlRequest(AbstractCommunicationManager.java:733)
at com.vaadin.terminal.gwt.server.CommunicationManager.handleUidlRequest(CommunicationManager.java:296)
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:483)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:326)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:227)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:228)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:822)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:719)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1013)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
at com.westhouse.crm.ui.ListView.getp(ListView.java:32)
at com.westhouse.crm.MainApplication.getListView(MainApplication.java:179)
at com.westhouse.crm.MainApplication.showShare(MainApplication.java:192)
at com.westhouse.crm.MainApplication.buttonClick(MainApplication.java:166)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:490)
... 35 moreI dont understand why its not possible to call ejb service from other then MainApp class. This is our first step and i am stuck within it.
Please help.