Hey all,
I'm trying to get cdi/injection to work with wicket. So far,
everything seems to be allright except for one thing: injecting into a
wicket-websession. Seems logical in some way, since a session is not a
component, so I tried using 'Injector.get().inject(this)', but
apparently, Injector.get() returns null. Injection into components
does work flawlessly (DaoService as well as other components are
injected into HomePage.java).
What am I missing?
Thanks,
Kurt
Mainapp.java
--
package mypackage;
import javax.enterprise.inject.spi.BeanManager;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import org.apache.wicket.Application;
import org.apache.wicket.Session;
import org.apache.wicket.cdi.CdiConfiguration;
import org.apache.wicket.protocol.http.WebApplication;
import org.apache.wicket.request.Request;
import org.apache.wicket.request.Response;
public class MainApp
extends WebApplication {
public MainApp() {
}
@Override
public void init() {
super.init();
BeanManager manager = null;
try {
manager = (BeanManager)
InitialContext.doLookup("java:comp/BeanManager");
} catch (NamingException e) {
e.printStackTrace();
}
new CdiConfiguration(manager).configure(this);
}
@Override
public void onDestroy() {
}
public Class<? extends org.apache.wicket.Page> getHomePage() {
return HomePage.class;
}
@Override
public final Session newSession(Request req, Response res) {
return new MySession(req);
}
}
--
MySession.java
--
package mypackage;
import javax.inject.Inject;
import org.apache.wicket.Session;
import org.apache.wicket.injection.Injector;
import org.apache.wicket.protocol.http.WebSession;
import org.apache.wicket.request.Request;
public class MySession
extends WebSession {
@Inject
DaoService daoService;
public static MySession get() {
return (MySession) Session.get();
}
MySession(Request req) {
super(req);
init();
}
private void init() {
Injector.get().inject(this);
}
private void test() {
daoService.someMethod();
}
}
--
I added the private void test-method to test if daoService is null.
However, there is a nullpointerexception earlier, at line
'Injector.get().inject(this)'. I avoid 'this' in the constructor, so I
put it in a init-method. That keeps the code a little cleaner, I
think.
DaoService.java:
--
package mypackage;
import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class DaoService {
@PersistenceContext(unitName="testPU")
private EntityManager entityManager;
public void someMethod() {
}
[...]
}
--
Injecting persistencecontext into daoservice does work fine.
HomePage.java
--
package mypackage;
import javax.inject.Inject;
import org.apache.wicket.markup.html.basic.Label
import org.apache.wicket.model.PropertyModel;
public class HomePage
extends BasePage {
@Inject
DaoService daoService;
@Inject
Clock clock;
public HomePage() {
add(new Label("time", new PropertyModel(this, "clock.time")));
daoService.someMethod();
}
}
--
No nullpointerexception or any other problem here.
I don't get any issues as long as I don't open the webapp (the
application starts fine). Some logs (line numbers are incorrect: line
number 28 is the one with 'Injector.get()'; I deleted some comments to
keep it a little more readable):
--
INFO: Server startup in 6005 ms
25-nov-2012 16:00:59 org.apache.wicket.DefaultExceptionMapper internalMap
SEVERE: Unexpected error occurred
java.lang.NullPointerException
at mypackage.MySession.init(MySession.java:28)
at mypackage.MySession.<init>(MySession.java:24)
at mypackage.MainApp.newSession(MainApp.java:45)
at
org.apache.wicket.Application.fetchCreateAndSetSession(Application.java:1557)
at org.apache.wicket.Session.get(Session.java:152)
at org.apache.wicket.Restart
[...]
25-nov-2012 16:00:59 org.apache.wicket.DefaultExceptionMapper map
SEVERE: unexpected exception when handling another exception: null
java.lang.NullPointerException
at mypackage.MySession.init(MySession.java:28)
at mypackage.MySession.<init>(MySession.java:24)
at mypackage.MainApp.newSession(MainApp.java:45)
at
org.apache.wicket.Application.fetchCreateAndSetSession(Application.java:1557)
at org.apache.wicket.Session.get(Session.java:152)
at
org.apache.wicket.RestartResponseAtInterceptPageException$InterceptData.get(RestartResponseAtInterceptPageException.java:146)
[...]
25-nov-2012 16:00:59 org.apache.wicket.DefaultExceptionMapper map
SEVERE: unexpected exception when handling another exception: null
java.lang.NullPointerException
at mypackage.MySession.init(MySession.java:28)
at mypackage.MySession.<init>(MySession.java:24)
at mypackage.MainApp.newSession(MainApp.java:45)
at
org.apache.wicket.Application.fetchCreateAndSetSession(Application.java:1557)
at org.apache.wicket.Session.get(Session.java:152)
at
org.apache.wicket.RestartResponseAtInterceptPageException$InterceptData.get(RestartResponseAtInterceptPageException.java:146)
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