Hi,
A very very wild guess: could it be a problem with dependencies so you have
on your classpath two versions of the same class? The JVM should choose
only one of them and use it, but to me it is clear it doesn't think that
the first "se.tradechannel.mifid.gateway.model.Gateway" is the same as the
latter "se.tradechannel.mifid.gateway.model.Gateway". So there must be two
versions of it somewhere.
On Wed, Mar 25, 2020 at 8:30 AM Mikael Andersson Wigander <
mikael.grevs...@gmail.com> wrote:
> TL;DR
>
> We have a very interesting mystery in one of our Camel applications.
>
> We have a route where we aggregate incoming messages.
> The messages are first unmarshalled from a JSON String to a Map<String,
> Object> and then processed thru a model ending up with a POJO of “Gateway
> objects".
> This POJO is then aggregated in a List<Gateway>. The POJO implements
> Serializable and has equals() and hash.
>
> The aggregationStrategy is from the example in documentation when wanting
> to aggregate a List…
>
> LevelDB is used for persistance Repository
>
> When flushed we process the Exchange and starts looping using a for-loop
>
> final List<Gateway> body=exchange.getIn().getBody(List.class);
> boolean hasObject=false;
> for(Gateway s:body){
> final InvestmentFirm investmentFirm=s.getInvestmentFirm();
> if(null!=investmentFirm){
> if(StringUtils.isNoneBlank(investmentFirm.getExternalId())){
> hasObject=true;
> break;
> }
> }
> }
>
>
> The thing is where we get an Exception at the start of the for-loop,
> saying :
>
> java.lang.ClassCastException: se.tradechannel.mifid.gateway.model.Gateway
> cannot be cast to se.tradechannel.mifid.gateway.model.Gateway
>
> I have debugged the code and the outcome of the aggregation is a
> List<Gateway> but when starting to loop we get the exception
>
>
> And if we step here it will crash.
>
> We have refactored the aggregation for this route; previously we
> unmarshalled the incoming JSON string to a Map<String, Object> and
> aggregated this in a List but here we use Object as the datatype. After
> flushing we execute the same logic with the for-loop and it runs fine…
>
> Below is a snippet of the code
>
> public void configure() throws Exception {
> final DefaultAggregateController defaultAggregateController = new
> DefaultAggregateController();
>
> final LevelDBAggregationRepository shuttleRepo = new
> LevelDBAggregationRepository("shuttleArt26",
> "mifir/data/shuttle/article26.dat");
>
>
> //tag::route[]
> from("{{shuttle.jms.incoming}}")
> .unmarshal().json(JsonLibrary.Jackson, true)
> .process(this::createShuttleObject)
> .aggregate(constant(true), new ArrayListAggregationStrategy())
> .aggregateController(defaultAggregateController)
> .aggregationRepository(shuttleRepo)
> .parallelProcessing(false)
> .completionSize(aggregation_size)
> .stopOnException()
> .to("direct:investmentFirm")
>
> .end();
>
>
> from("direct:investmentFirm")
> .choice()
> .when(exchange -> { //<.>
> final List<Gateway> body =
> exchange.getIn().getBody(List.class);
> boolean hasObject = false;
> for (Gateway s : body) {
> final InvestmentFirm investmentFirm =
> s.getInvestmentFirm();
> if (null != investmentFirm) {
> if
> (StringUtils.isNoneBlank(investmentFirm.getExternalId())) {
> hasObject = true;
> break;
> }
> }
> }
> log.debug("InvestmentFirms = " + hasObject);
> return hasObject;
> })
> .end();
>
> }
>
> public class ArrayListAggregationStrategy implements AggregationStrategy {
> public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
> List<Gateway> newBody = newExchange.getIn().getBody(ArrayList.class);
> List<Gateway> list;
>
>
> //Ignore Exception here
> if (null != newExchange.getException()) {
> return oldExchange;
> }
>
> //First Exchange to aggregate
> if (null == oldExchange) {
> list = new ArrayList<>(newBody);
> newExchange.getIn().setBody(list);
> return newExchange;
> } else {
> list = oldExchange.getIn().getBody(ArrayList.class);
> list.addAll(newBody);
> oldExchange.getIn().setBody(list);
> return oldExchange;
> }
> }
> }
>
>
>
>
>
> We really can’t see what the heck is going on, it seems OK everything but
> "the computer says No!”
>
> Anyone?
>
> Thx
>
> M
>
