I have several UI-Components which have listeners. All these listeners invoke method dialogChanged(). My goal is to make some long processing in this method and don't let the UI freeze. According to Lars Vogel it is possible to do this with help of UISynchronize being injected during runtime. But it fails for me, field of this type is not being injected and i get a NullPointerException. Here's relevant part of my code:
#Inject UISynchronize sync;
Job job = new Job("My Job") {
#Override
protected IStatus run(IProgressMonitor arg0)
{
sync.asyncExec(new Runnable()
{
#Override
public void run()
{
updateStatus("Checking connection...");
if (bisInstallDirSelected)
bisSettingsChanged();
else
jarSettingsChanged();
}
});
return Status.OK_STATUS;
}
};
protected void dialogChanged()
{
job.schedule();
}
The methods updateStatus(String s), bisSettingsChanged() and jarSettingsChanged() interact with UI, to be presice, they use method setErrorMessage(String newMessage) of superclass org.eclipse.jface.wizard.WizardPage
I'd appreciate if somebody could tell me what I am doing wrong or suggest a better way to handle this problem.
You can only use #Inject in classes that the e4 application model creates (such as the class for a Part or a Command Handler).
You can also use ContextInjectionFactory to do injection on your own classes.
For classes where injection has not been done you can use the 'traditional' way of running code in the UI thread:
Display.getDefault().asyncExec(runnable);
Related
I'm working on a code in a wicket project, where the original devs used the onModelChanged() method quite a lot in Ajax request handling methods. I, for one, however am not a strong believer of this implementation.
In fact, I can't think of any examples, where calling the target.add(...) is inferior to calling the onModelChanged method.
Am I missing some key concepts here?
Example:
public MyComponent extends Panel {
public MyComponent(String id, Component... componentsToRefresh) {
add(new AjaxLink<Void>("someId") {
#Override
public void onClick(AjaxRequestTarget target) {
// some logic with model change
for(Component c: componentsToRefresh) {
c.modelChanged();
}
target.add(componentsToRefresh);
}
};
}
}
Now, there are a couple of things I don't agree with, the very first is the componentsToRefresh parameter, the second is (as the question suggests), the fact that we called c.modelChanged() on all components in that array. My guess would be that it is completely un necessary and instead of a parameter in the constructor, one should just write an empty function in MyComponent and override it, and put the necessary components in there when needed.
I would suggest to use Wicket Event system instead. That is, whenever the AjaxLink is clicked you will broadcast an event:
send(getPage(), Broadcast.BREATH, new MyEventPayload(target));
This will broadcast the event to the current Page and all its components.
Then in any of your components you can listen for events:
#Override
public void onEvent(IEvent event) {
Object payload = event.getPayload();
if (payload instanceof MyEventPayload) {
((MyEventPayload) payload).getTarget().add(this); // or any of my sub-components
event.stop(); // optionally you can stop the broadcasting
}
}
This way you do not couple unrelated components in your application.
See Wicket Guide for more information.
I'm struggling with Play and JPA in order to be able to use two different javax.persistence.Entity model associated to two different persistence units (needed to be able to connect to different DB - for example an Oracle and a MySQL db).
The problem come from the Transaction which is always bind to the default JPA persitenceUnit (see jpa.default option).
Here is two controller actions which show the solution I found to manually define the persistence :
package controllers;
import models.Company;
import models.User;
import play.db.jpa.JPA;
import play.db.jpa.Transactional;
import play.mvc.Controller;
import play.mvc.Result;
public class Application extends Controller {
//This method run with the otherPersistenceUnit
#Transactional(value="other")
public static Result test1() {
JPA.em().persist(new Company("MyCompany"));
//Transaction is run with the "defaultPersistenceUnit"
JPA.withTransaction(new play.libs.F.Callback0() {
#Override
public void invoke() throws Throwable {
JPA.em().persist(new User("Bobby"));
}
});
return ok();
}
//This action run with the otherPersistenceUnit
#Transactional
public static Result test2() {
JPA.em().persist(new User("Ryan"));
try {
JPA.withTransaction("other", false, new play.libs.F.Function0<Void>() {
public Void apply() throws Throwable {
JPA.em().persist(new Company("YourCompany"));
return null;
}
});
} catch (Throwable throwable) {
throw new RuntimeException(throwable);
}
return ok();
}
}
This solution doesn't seem to be really "clean". I'd like to know if you know a better way to avoid the need to manually modify the transaction used.
For this purpose, I created a repo on git with a working sample application which shows how I configured the project.
https://github.com/cm0s/play2-jpa-multiple-persistenceunit
Thank you for your help
i met the same problem, too. too many advices are about PersistenceUnit annotation or getJPAConfig. but both them seem not work in play framework.
i found out a method which works well in my projects. maybe you can try it.
playframework2 how to open multi-datasource configuration with jpa
gud luk!
For some reason after I had added and removed a static vairable from my code, eclipse started giving me errors on all functions that I call, saying that these functions must be static. However, if I let the program run with these errors, the program runs just as I intended it to do. My Code:
package main;
public class Main implements Runnable {
public void start() {
Thread thread = new Thread(this);
thread.start();
System.out.println("Running...");
Ball.test(); <--- Giving me an error
}
public void run() {
}
public void stop() {
System.out.println("Exiting...");
}
}
and when I create a method in ball called test it gives me:
public static void test() {
// TODO Auto-generated method stub
}
Well yes - you're calling the method as if it were a static method:
Ball.test()
If you want to call an instance method, you need to call it on an instance, e.g.
Ball ball = new Ball();
ball.test();
It's important to understand the difference between static members and instance members. Have you read the appropriate chapter of the Java tutorial? Do you have a good Java book which would help you? (Stack Overflow is great for specific questions, but not good for learning a language from scratch. Explaining language concepts well takes a lot of space and time.)
In my GWT application i'm trying to setup a DI mechanism wihich would allow me to have all the commonly necessary stuff at hand everywhere. I'm using google-gin which is an adaptation of guice for GWT. I have an injector interface defined as this:
#GinModules(InjectionClientModule.class)
public interface MyInjector extends Ginjector {
public PlaceController getPlaceController();
public Header getHeader();
public Footer getFooter();
public ContentPanel getContent();
public EventBus getEventBus();
public PlaceHistoryHandler getPlaceHistoryHandler();
}
My injection module is this:
public class InjectionClientModule extends AbstractGinModule {
public InjectionClientModule() {
super();
}
protected void configure() {
bind(Header.class).in(Singleton.class);
bind(Footer.class).in(Singleton.class);
bind(ContentPanel.class).in(Singleton.class);
bind(EventBus.class).to(SimpleEventBus.class).in(Singleton.class);
bind(PlaceController.class).toProvider(PlaceControllerProvider.class).asEagerSingleton();
bind(PlaceHistoryHandler.class).toProvider(PlaceHistoryHandlerProvider.class).asEagerSingleton();
}
}
When calling MyInjector injector = GWT.create(MyInjector.class); i'm gettign the following exception:
java.lang.NullPointerException: null
at com.google.gwt.inject.rebind.BindingsProcessor.createImplicitBinding(BindingsProcessor.java:498)
at com.google.gwt.inject.rebind.BindingsProcessor.createImplicitBindingForUnresolved(BindingsProcessor.java:290)
at com.google.gwt.inject.rebind.BindingsProcessor.createImplicitBindingsForUnresolved(BindingsProcessor.java:278)
at com.google.gwt.inject.rebind.BindingsProcessor.process(BindingsProcessor.java:240)
at com.google.gwt.inject.rebind.GinjectorGeneratorImpl.generate(GinjectorGeneratorImpl.java:76)
at com.google.gwt.inject.rebind.GinjectorGenerator.generate(GinjectorGenerator.java:47)
at com.google.gwt.core.ext.GeneratorExtWrapper.generate(GeneratorExtWrapper.java:48)
at com.google.gwt.core.ext.GeneratorExtWrapper.generateIncrementally(GeneratorExtWrapper.java:60)
at com.google.gwt.dev.javac.StandardGeneratorContext.runGeneratorIncrementally(StandardGeneratorContext.java:647)
at com.google.gwt.dev.cfg.RuleGenerateWith.realize(RuleGenerateWith.java:41)
at com.google.gwt.dev.shell.StandardRebindOracle$Rebinder.rebind(StandardRebindOracle.java:78)
at com.google.gwt.dev.shell.StandardRebindOracle.rebind(StandardRebindOracle.java:268)
at com.google.gwt.dev.shell.ShellModuleSpaceHost.rebind(ShellModuleSpaceHost.java:141)
at com.google.gwt.dev.shell.ModuleSpace.rebind(ModuleSpace.java:585)
at com.google.gwt.dev.shell.ModuleSpace.rebindAndCreate(ModuleSpace.java:455)
at com.google.gwt.dev.shell.GWTBridgeImpl.create(GWTBridgeImpl.java:49)
at com.google.gwt.core.client.GWT.create(GWT.java:97)
The problem is that the PlaceController class actually depends on one of the other dependencies. I've implemented it's provider like this:
public class PlaceControllerProvider implements Provider<PlaceController> {
private final PlaceController placeController;
#Inject
public PlaceControllerProvider(EventBus eventBus) {
this.placeController = new PlaceController(eventBus);
}
#Override
public PlaceController get() {
return placeController;
}
}
what should i change for this to work?
Old question but having the same problem I kept falling here. I finally found the way to know which class is messing during ginjection.
When I launch my app in development mode and put stack to Trace, I noticed there is a step called : "Validating newly compiled units".
Under this, I had an error but I didn't notice it since I had to expand 2 nodes which weren't even in red color.
The error was "No source code available for type com.xxx.xxxx ...", which was due to a bad import on client side which couldn't be converted to Javascript.
Hope this may help other here !
While I'm not actually seeing how the errors you're getting are related to the PlaceController being injected, I do see that the provider is returning a singleton PlaceController even if the provider were not bound as an eager singleton or in a different scope. The correct way to write that provider would be:
public class PlaceControllerProvider implements Provider<PlaceController> {
private final EventBus eventBus;
#Inject
public PlaceControllerProvider(EventBus eventBus) {
this.eventBus = eventBus;
}
#Override
public PlaceController get() {
return new PlaceController(eventBus);
}
}
Let guice handle the scoping i.e. "Letting guice work for you".
Other than that, I almost bet that your problem is due to the use of asEagerSingleton. I recommend you try this with just in(Singleton.class) and I further posit that you didn't really need the singleton to be eager. It seems others had problems with the behavior too, there's some indication that it has to do with overusing asEagerSingleton or misunderstanding the #Singleton annotation in a few cases.
I also got a lot of NullPointerException warnings using GIN 1.x with no real explanation of what happened. When I upgraded to gin 2.0 I was told with high accuracy what the error was. You might be helped by upgrading to the 2.0 version that was released a year after you asked this question.
Had the same problem problem, same trace, and the error was that I used "server" classes in my "client" classes, so GIN can't find these classes.
I mean by "server" and "client" the packages in my project.
Hope this could help
I'm working on trying to get an AsyncController to work in OrchardProject. The current version I'm using is 2.2.4.9.0.
I've had 2 people eyeball my code: http://www.pastie.org/2117952 (AsyncController) which works fine in a regular MVC3 vanilla application.
Basically, I can route to IndexCompleted, but I can't route to Index. I am going to assume i'm missing something in the Autofac configuration of the overall project.
I think the configuration is in the global.asax: http://pastie.org/2118008
What I'm looking for is some guidance on if this is the correct way to implement autofac for AsyncControllers, or if there is something/someplace else I need to implement/initialize/etc.
~Dan
Orchard appears to register its own IActionInvoker, called Orchard.Mvc.Filters.FilterResolvingActionInvoker.
This class derives from ControllerActionInvoker. At a guess, in order to support async actions, it should instead derive from AsyncControllerActionInvoker.
Hope this helps!
Nick
The Autofac setup looks ok, and as long as you can navigate to something I cannot say that your assumption makes sense. Also, the pattern you are using for initialization in global.asax is used by others too.
The AsyncController requires that async methods come in pairs, in your case IndexAsync & IndexCompleted. These together represent the Index action. When you say you can navigate to IndexCompleted, do you mean that you open a url "..../IndexCompleted"?
Also, and this I cannot confirm from any documentation, but I would guess that AsyncController requires that all actions are async. Thus, your NewMessage action causes trouble and should be converted to an async NewMessageAsync & NewMessageCompleted pair.
I did too needed to have AsyncController which I easily changed FilterResolvingActionInvoker to be based on AsyncControllerActionInvoker instead of ControllerActionInvoker.
But there was other problems because of automatic transaction disposal after completion of request. In AsyncController starting thread and the thread that completes the request can be different which throws following exception in Dispose method of TransactionManager class:
A TransactionScope must be disposed on the same thread that it was created.
This exception is suppressed without any logging and really was hard to find out. In this case session remains not-disposed and subsequent sessions will timeout.
So I made dispose method public on ITransactionManager and now in my AsyncController, whenever I need a query to database I wrap it in:
using (_services.TransactionManager) {
.....
}
new TransactionManager :
public interface ITransactionManager : IDependency, IDisposable {
void Demand();
void Cancel();
}
public class TransactionManager : ITransactionManager {
private TransactionScope _scope;
private bool _cancelled;
public TransactionManager() {
Logger = NullLogger.Instance;
}
public ILogger Logger { get; set; }
public void Demand() {
if (_scope == null) {
Logger.Debug("Creating transaction on Demand");
_scope = new TransactionScope(
TransactionScopeOption.Required,
new TransactionOptions {
IsolationLevel = IsolationLevel.ReadCommitted
});
_cancelled = false;
}
}
void ITransactionManager.Cancel() {
Logger.Debug("Transaction cancelled flag set");
_cancelled = true;
}
void IDisposable.Dispose() {
if (_scope != null) {
if (!_cancelled) {
Logger.Debug("Marking transaction as complete");
_scope.Complete();
}
Logger.Debug("Final work for transaction being performed");
try {
_scope.Dispose();
}
catch {
// swallowing the exception
}
Logger.Debug("Transaction disposed");
}
_scope = null;
}
}
Please notice that I have made other small changes to TransactionManager.
I tried the AsyncControllerActionInvoker route as well to no avail. I would get intermittent errors from Orchard itself with the following errors:
Orchard.Exceptions.DefaultExceptionPolicy - An unexpected exception was caught
System.TimeoutException: The operation has timed out.
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End()
at System.Web.Mvc.Async.ReflectedAsyncActionDescriptor.EndExecute(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass3f.<BeginInvokeAsynchronousActionMethod>b__3e(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
NHibernate.Util.ADOExceptionReporter - While preparing SELECT this_.Id as Id236_2_, this_.Number as Number236_2_,...<blah blah blah>
NHibernate.Util.ADOExceptionReporter - The connection object can not be enlisted in transaction scope.
So I don't think just wrapping your own database calls with a transaction object will help. The innards of Orchard would have to modified as well.
Go vote for this issue if you want AsyncControllers supported in Orchard:
https://orchard.codeplex.com/workitem/18012