spring service null in managed bean

Question

Hi I have a problem with spring. When I call a service from my managedbean I have a NullPointerException In my applicationContext I have the configurarion:

<context:annotation-config/>
<context:component-scan base-package="com.sertec" />

My source code is:

@ManagedBean(name="estacionController")
@Scope("view")
public class EstacionController {
    private List<Estacion> estacionesActivas;
    private Estacion estacionSeleccionada;

    @Autowired
    EstacionService estacionService;

    @PostConstruct
    private void init() {
        estacionesActivas = estacionService.getEstacionesActivas();
    }
    public List<Estacion> getEstacionesActivas() {
        return estacionesActivas;
    }
    public void setEstacionesActivas(List<Estacion> estacionesActivas) {
        this.estacionesActivas = estacionesActivas;
    }
    public Estacion getEstacionSeleccionada() {
        return estacionSeleccionada;
    }
    public void setEstacionSeleccionada(Estacion estacionSeleccionada) {
        this.estacionSeleccionada = estacionSeleccionada;
    }   
}

Station service interface is:

public interface EstacionService {
    public List<Estacion> getEstacionesActivas();
    public Estacion findEstacionByAcronimo(String acronimo);
}

And the implementation is:

@Service("estacionService")
public class EstacionServiceImpl implements EstacionService {

    @Autowired
    EstacionDao estacionDao;

    @Override
    public List<Estacion> getEstacionesActivas() {
        return estacionDao.getEstacionesActivas();
    }

    @Override
    public Estacion findEstacionByAcronimo(String acronimo) {
        return estacionDao.findEstacionByAcronimo(acronimo);
    }

}

the log is:

GRAVE: com.sun.faces.mgbean.ManagedBeanCreationException: Se ha producido un error al realizar la inyección de recurso en el bean administrado estacionController
    at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:227)
    at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:103)
    at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
    at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
    at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:257)
    at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:117)
    at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
    at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
    at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:94)
    at org.apache.el.parser.AstValue.getValue(AstValue.java:137)
    at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:184)
    at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
    at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
    at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
    at javax.faces.component.UISelectItems.getValue(UISelectItems.java:129)
    at org.primefaces.renderkit.InputRenderer.getSelectItems(InputRenderer.java:54)
    at org.primefaces.component.selectonemenu.SelectOneMenuRenderer.encodeMarkup(SelectOneMenuRenderer.java:80)
    at org.primefaces.component.selectonemenu.SelectOneMenuRenderer.encodeEnd(SelectOneMenuRenderer.java:74)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeDynamicBody(PanelGridRenderer.java:131)
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeTableBody(PanelGridRenderer.java:102)
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeTableLayout(PanelGridRenderer.java:65)
    at org.primefaces.component.panelgrid.PanelGridRenderer.encodeEnd(PanelGridRenderer.java:37)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)
    at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:85)
    at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:72)
    at org.primefaces.component.layout.LayoutUnitRenderer.encodeEnd(LayoutUnitRenderer.java:49)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at com.sun.faces.context.PartialViewContextImpl.renderAll(PartialViewContextImpl.java:455)
    at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:313)
    at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:219)
    at org.primefaces.context.PrimePartialViewContext.processPartial(PrimePartialViewContext.java:57)
    at javax.faces.component.UIViewRoot.encodeChildren(UIViewRoot.java:1004)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:430)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:78)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:789)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1437)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)
Caused by: com.sun.faces.spi.InjectionProviderException
    at com.sun.faces.vendor.WebContainerInjectionProvider.invokeAnnotatedMethod(WebContainerInjectionProvider.java:115)
    at com.sun.faces.vendor.WebContainerInjectionProvider.invokePostConstruct(WebContainerInjectionProvider.java:95)
    at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:221)
    ... 72 more
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.faces.vendor.WebContainerInjectionProvider.invokeAnnotatedMethod(WebContainerInjectionProvider.java:113)
    ... 74 more
Caused by: java.lang.NullPointerException
    at com.sertec.controllers.EstacionController.init(EstacionController.java:25)
    ... 79 more

All classess are inside the package com.sertec

Answer 1

The NullPointerException occurs because estacionService is null at the point in time when you try to call estacionService.getEstacionesActivas() .

You could change this:

@Autowired
EstacionService estacionService;

@PostConstruct
private void init() {
    estacionesActivas = estacionService.getEstacionesActivas();
}

... to this:

EstacionService estacionService;

@Autowired
private void setEstacionService(EstacionService estacionService) {
    this.estacionService = estacionService;
    estacionesActivas = estacionService.getEstacionesActivas();
}

... which would ensure that the call to estacionService.getEstacionesActivas() only occurs in response to the autowiring.

I suspect the root of the problem exists somewhere else in your code (a by-product of other autowiring and post-constructs).

Perhaps this SO post may be of some help?

Answer 2

Finally there was an error in my faces-config.xml file

<faces-config>
 .......
<application>
.....
<el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
 .......
</application>
.......
</faces-config>