PlayFramework 2.5 - Execution exception[[CompletionException: java.util.ConcurrentModificationException: java.util.ConcurrentModificationException]]

[404NotFound]

When I am sending HTTP requests to play controller faster then usually, I am getting this error:

Execution exception[[CompletionException: java.util.ConcurrentModificationException: java.util.ConcurrentModificationException]]

Its happening in this part of code:

this.points=layer.points!=null ? layer.points.parallelStream().map(point -> new FPoint(point,messages)).collect(Collectors.toList()) : new ArrayList<>();

Whole stack:

play.api.http.HttpErrorHandlerExceptions$$anon$1: Execution exception[[CompletionException: java.util.ConcurrentModificationException: java.util.ConcurrentModificationException]]

at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:280)

at play.api.http.HttpErrorHandlerExceptions.throwableToUsefulException(HttpErrorHandler.scala)

at play.http.DefaultHttpErrorHandler.throwableToUsefulException(DefaultHttpErrorHandler.java:169)

at play.http.DefaultHttpErrorHandler.onServerError(DefaultHttpErrorHandler.java:131)

at play.core.j.JavaHttpErrorHandlerAdapter$$anonfun$onServerError$1.apply(JavaHttpErrorHandlerAdapter.scala:22)

at play.core.j.JavaHttpErrorHandlerAdapter$$anonfun$onServerError$1.apply(JavaHttpErrorHandlerAdapter.scala:22)

at play.core.j.JavaHelpers$$anonfun$invokeWithContext$1.apply(JavaHelpers.scala:142)

at play.core.j.JavaHelpers$$anonfun$invokeWithContext$1.apply(JavaHelpers.scala:141)

at play.core.j.JavaHelpers$class.withContext(JavaHelpers.scala:153)

at play.core.j.JavaHelpers$.withContext(JavaHelpers.scala:162)

Caused by: java.util.concurrent.CompletionException: java.util.ConcurrentModificationException: java.util.ConcurrentModificationException

at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:292)

at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:308)

at java.util.concurrent.CompletableFuture.uniApply(CompletableFuture.java:593)

at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:577)

at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)

at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1977)

at scala.concurrent.java8.FuturesConvertersImpl$CF.apply(FutureConvertersImpl.scala:21)

at scala.concurrent.java8.FuturesConvertersImpl$CF.apply(FutureConvertersImpl.scala:18)

at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:32)

at scala.concurrent.BatchingExecutor$Batch$$anonfun$run$1.processBatch$1(BatchingExecutor.scala:63)

Caused by: java.util.ConcurrentModificationException: java.util.ConcurrentModificationException

at sun.reflect.GeneratedConstructorAccessor78.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

at java.lang.reflect.Constructor.newInstance(Constructor.java:423)

at java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:593)

at java.util.concurrent.ForkJoinTask.reportException(ForkJoinTask.java:677)

at java.util.concurrent.ForkJoinTask.invoke(ForkJoinTask.java:735)

at java.util.stream.ReduceOps$ReduceOp.evaluateParallel(ReduceOps.java:714)

at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:233)

at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)

at controllers.liek.api.results.TLayer.<init>(TLayer.java:195)

Caused by: java.util.ConcurrentModificationException: null

at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)

at java.util.ArrayList$Itr.next(ArrayList.java:851)

at com.avaje.ebean.common.ModifyIterator.next(ModifyIterator.java:39)

at java.util.Iterator.forEachRemaining(Iterator.java:116)

at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)

at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)

at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)

at java.util.stream.ReduceOps$ReduceTask.doLeaf(ReduceOps.java:747)

at java.util.stream.ReduceOps$ReduceTask.doLeaf(ReduceOps.java:721)

at java.util.stream.AbstractTask.compute(AbstractTask.java:316)

As ORM I am using Ebean. There is no modification with update , or insert happening in this part of code only selects.

Controller looks like this:

 @BodyParser.Of(BodyParser.Json.class)
 @Transactional
    public Result getLayerByID(){
        Messages messages=messagesApi.preferred(request());
        Form<FInputData> search=formFactory.form(FInputData.class).bindFromRequest();
        if (search.hasErrors()) {
            return badRequest(search.errorsAsJson());
        }
        FSearchData fSearchData = search.get();
        User actualUser = userService.actualUser(ctx());
        Result res=null;
        if (fSearchData !=null) {
            result=layerService.findByID(fSearchData.ID);
        }
        if (result==null) {
                return badRequest(Json.toJson(new TAction(messages.at("layer.doesNotExists",fSearchData.ID))));
        }
        TLayer tResult=result!=null ? new TLayer(result,actualUser ,messages) : null;
        return ok(Json.toJson(tResult!=null ?  tResult : new TEmpty() ));
    }



layerService.findByID(..) is actually making 20+ selects to database. Where could be problem?

I am using 

addSbtPlugin("com.typesafe.sbt" % "sbt-play-ebean" % "3.1.0")
which should support JAVA8 streams...

[404NotFound]

Also I am getting other strange errors like:

Caused by: java.util.concurrent.CompletionException: javax.persistence.EntityNotFoundException: Lazy loading failed on type:models.PointOfInterest id:25 - Bean has been deleted

 when spam clicking to call other controller. And on next request there is no such error and then randomly on next request there is this error , while parameters for all requests are same and no other request has been made between them (its on developing machine)

[404NotFound]

All these errors are ocurring randomly and only when spaming request to controller

All these errors are ocurring randomly and only when spaming request to controller

All these errors are ocurring randomly and only when spaming request to controller

All these errors are ocurring randomly and only when spaming request to controller

All these errors are ocurring randomly and only when spaming request to controller

All these errors are ocurring randomly and only when spaming request to controller 

[404NotFound]

I have rewritten all ".parallelStream()" back to java7 loops and these errors does not occur anymore. So there is some problem with java8 implementation (probably in ebean.)

[Greg Methvin]

Yeah, from looking at it originally it didn't seem like a Play issue. You might want to ask on the Ebean mailing list: https://groups.google.com/forum/#!forum/ebean

Greg

_____________________________
From: 404NotFound <oby...@gmail.com>
Sent: Saturday, April 1, 2017 16:30
Subject: [play-framework] Re: PlayFramework 2.5 - Execution exception[[CompletionException: java.util.ConcurrentModificationException: java.util.ConcurrentModificationException]]
To: Play Framework <play-fr...@googlegroups.com>

I have rewritten all ".parallelStream()" back to java7 loops and these errors does not occur anymore. So there is some problem with java8 implementation (probably in ebean.)

--
You received this message because you are subscribed to the Google Groups "Play Framework" group.
To unsubscribe from this group and stop receiving emails from it, send an email to play-framewor...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/play-framework/298d2ddb-1ee5-4131-89bc-3c3bab2fcca2%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[alex s]

воскресенье, 2 апреля 2017 г., 2:30:10 UTC+3 пользователь 404NotFound написал:

I have rewritten all ".parallelStream()" back to java7 loops and these errors does not occur anymore.

http://stackoverflow.com/questions/35689495/does-ebean-support-multithreading