Hi, Issac is right, you should not assigned the service dependency to null, because it overrides the value injected by iPOJO.
Regards, Clement On 07.10.2011, at 23:25, Issac Noé García wrote: > The problem I think is with the line: > > /** Reference to the dispatcher to use. */ > private EventDispatcher dispatcher = null; > > As you initialize the field (even with null), there is a strange behavior > (Clement could explain it better) that make that > your field has always the reference to null. So if you want iPOJO to handle > the injections, you should leave fields without assign some value. > > regards > > 2011/10/7 Benoît Thiébault <thieba...@artenum.com> > >> Hi Clément, >> >> Here is my configuration. >> >> In a first bundle called "messaging", I have an EventDispatcher and a >> default implementation that is instantiated and provided as a service by >> iPOJO (I don't use annotations so that my classes remain POJOs): >> >> <component classname="org.messaging.internal.DefaultEventDispatcher" >> name="DefaultEventDispatcher" >> public="true" >> immediate="true"> >> <callback transition="invalidate" method="terminate" /> >> <provides /> >> </component> >> <instance component="DefaultEventDispatcher" /> >> >> The EventDispatcher, as its names implies, dispatches events from one >> bundle to another. It will potentially be used in a lot of classes by a >> lot of bundles. >> >> Its usage is however not very simple and I have created, in the same >> bundle, a helper class, called EventBuilder, to simplify the dispatching >> of events. It is declared in iPOJO like this: >> <component classname="org.messaging.EventBuilder" >> name="EventBuilder" >> public="true"> >> <requires field="dispatcher" /> >> </component> >> <instance component="EventBuilder" /> >> >> It is a based on the builder design pattern >> (http://drdobbs.com/java/208403883?pgno=2) and is called statically by >> my bundles like this: >> EventBuilder.event(myEventKey).triggerCallEvent(); >> or >> EventBuilder.event(myEventKey).triggerSignalEvent(); >> etc. >> >> The EventBuilder class contains a reference to the dispatcher and I >> would like this instance to be injected automatically. >> >> The implementation looks like this (this is a simplified version of it): >> >> public final class EventBuilder { >> /** Unique instance of the builder */ >> private static final EventBuilder INSTANCE = new EventBuilder(); >> /** Event to trigger. */ >> private static Event eventToTrigger; >> /** Reference to the dispatcher to use. */ >> private EventDispatcher dispatcher = null; >> /** Lock to prevent concurrent modifications. */ >> private static final Lock LOCK = new ReentrantLock(); >> >> public static EventBuilder event(final EventKey key) { >> LOCK.lock(); >> eventToTrigger = new DefaultEvent(key); >> return INSTANCE; >> } >> >> public void triggerCallEvent() { >> try { >> dispatcher.triggerCallEvent(eventToTrigger); >> } finally { >> LOCK.unlock(); >> } >> } >> } >> >> I have a HelloWorld bundle that just calls the Builder in its start() >> method. The stack trace is (line 81 of the EventBuilder is the one that >> calls dispatcher.triggerCallEvent(eventToTrigger);... apparently, the >> injection is not done): >> >> [ERROR] : [HelloWorldBundleStarter-0] The callback method start has >> thrown an exception : null >> java.lang.NullPointerException >> at >> org.messaging.EventBuilder.__triggerCallEvent(EventBuilder.java:81) >> at org.messaging.EventBuilder.triggerCallEvent(EventBuilder.java) >> at org.helloworld.osgi.BundleStarter.__start(BundleStarter.java:23) >> at org.helloworld.osgi.BundleStarter.start(BundleStarter.java) >> 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 org.apache.felix.ipojo.util.Callback.call(Callback.java:237) >> at org.apache.felix.ipojo.util.Callback.call(Callback.java:193) >> at >> >> org.apache.felix.ipojo.handlers.lifecycle.callback.LifecycleCallback.call(LifecycleCallback.java:86) >> at >> >> org.apache.felix.ipojo.handlers.lifecycle.callback.LifecycleCallbackHandler.__stateChanged(LifecycleCallbackHandler.java:162) >> at >> >> org.apache.felix.ipojo.handlers.lifecycle.callback.LifecycleCallbackHandler.stateChanged(LifecycleCallbackHandler.java) >> at >> org.apache.felix.ipojo.InstanceManager.setState(InstanceManager.java:471) >> at >> org.apache.felix.ipojo.InstanceManager.start(InstanceManager.java:353) >> at >> >> org.apache.felix.ipojo.ComponentFactory.createInstance(ComponentFactory.java:166) >> at >> >> org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:301) >> at >> >> org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:238) >> at org.apache.felix.ipojo.InstanceCreator >> $ManagedInstance.create(InstanceCreator.java:343) >> at >> org.apache.felix.ipojo.InstanceCreator.addInstance(InstanceCreator.java:89) >> at org.apache.felix.ipojo.Extender.parse(Extender.java:269) >> at >> org.apache.felix.ipojo.Extender.startManagementFor(Extender.java:208) >> at org.apache.felix.ipojo.Extender.access$600(Extender.java:52) >> at >> org.apache.felix.ipojo.Extender$CreatorThread.run(Extender.java:682) >> at java.lang.Thread.run(Thread.java:662) >> [ERROR] : null >> java.lang.IllegalStateException >> at >> >> org.apache.felix.ipojo.handlers.lifecycle.callback.LifecycleCallbackHandler.__stateChanged(LifecycleCallbackHandler.java:171) >> at >> >> org.apache.felix.ipojo.handlers.lifecycle.callback.LifecycleCallbackHandler.stateChanged(LifecycleCallbackHandler.java) >> at >> org.apache.felix.ipojo.InstanceManager.setState(InstanceManager.java:471) >> at >> org.apache.felix.ipojo.InstanceManager.start(InstanceManager.java:353) >> at >> >> org.apache.felix.ipojo.ComponentFactory.createInstance(ComponentFactory.java:166) >> at >> >> org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:301) >> at >> >> org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:238) >> at org.apache.felix.ipojo.InstanceCreator >> $ManagedInstance.create(InstanceCreator.java:343) >> at >> org.apache.felix.ipojo.InstanceCreator.addInstance(InstanceCreator.java:89) >> at org.apache.felix.ipojo.Extender.parse(Extender.java:269) >> at >> org.apache.felix.ipojo.Extender.startManagementFor(Extender.java:208) >> at org.apache.felix.ipojo.Extender.access$600(Extender.java:52) >> at >> org.apache.felix.ipojo.Extender$CreatorThread.run(Extender.java:682) >> at java.lang.Thread.run(Thread.java:662) >> >> >> Le mardi 04 octobre 2011 à 16:36 +0200, Clement Escoffier a écrit : >>> Hi, >>> >>> This scenario is supported out of the box. >>> >>> Let's imagine a simple component A: >>> @Component(name="comp-a") >>> @Provides >>> class Component1 >>> { >>> @Validate >>> public void init() { >>> System.out.println("Ping from " + getClass()); >>> } >>> >>> public boolean doSomething() { >>> System.out.println("I'm doing something cool"); >>> return true; >>> } >>> } >>> >>> Let's also imagine a simple component B (in the same bundle): >>> @Component(name="comp-b") >>> class Component2 >>> { >>> @Requires >>> private Component1 cmp; >>> >>> >>> @Validate >>> public void init() { >>> System.out.println("Ping from " + getClass()); >>> System.out.println(cmp.doSomething()); >>> } >>> } >>> >>> And now, the metadata.xml declaring the instances: >>> <ipojo xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; >>> xsi:schemaLocation="org.apache.felix.ipojo >> http://felix.apache.org/ipojo/schemas/CURRENT/core.xsd"; >>> xmlns="org.apache.felix.ipojo" >> xmlns:c="org.apache.felix.ipojo.composite"> >>> >>> <instance component="comp-a" /> >>> <instance component="comp-b" /> >>> >>> </ipojo> >>> >>> If you deploy this bundle, you will see: >>> Ping from class >> ipojo.test.org.apache.felix.ipojo.instance.injection.Component1 >>> Ping from class >> ipojo.test.org.apache.felix.ipojo.instance.injection.Component2 >>> I'm doing something cool >>> true >>> >>> So, nothing else should be required. Could you give me more details about >> your case as well as the stack trace. >>> >>> Regards, >>> >>> Clement >>> >>> On 04.10.2011, at 09:57, Benoît Thiébault wrote: >>> >>>> Hi everyone, >>>> >>>> I'm using iPOJO in my application and I would like to inject a service >>>> instance in another class of the same bundle. >>>> >>>> Something like this: >>>> <iPOJO xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; >>>> xmlns="org.apache.felix.ipojo" >>>> xsi:schemaLocation="org.apache.felix.ipojo >>>> http://felix.apache.org/ipojo/schemas/CURRENT/core.xsd";> >>>> <component classname="org.test.ServiceImpl" >>>> name="ServiceImpl" public="true" immediate="true"> >>>> <callback transition="invalidate" method="terminate" /> >>>> <provides /> >>>> </component> >>>> <instance component="ServiceImpl" /> >>>> <component classname="org.test.User" >>>> name="User" public="true"> >>>> <requires field="serviceInstance"/> >>>> </component> >>>> <instance component="User" /> >>>> </iPOJO> >>>> >>>> Is is supported by iPOJO? Is there a special way to do it? >>>> >>>> I tried it and have a null pointer exception on the instance... >>>> >>>> Kind regards >>>> >>>> Ben >>>> >>>> >>>> --------------------------------------------------------------------- >>>> To unsubscribe, e-mail: users-unsubscr...@felix.apache.org >>>> For additional commands, e-mail: users-h...@felix.apache.org >>>> >>> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@felix.apache.org >> For additional commands, e-mail: users-h...@felix.apache.org >> >> > > > -- > Issac Noé García Garza --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@felix.apache.org For additional commands, e-mail: users-h...@felix.apache.org
