Trying to implement the pagination with Micronaut data with MongoDB as below
@MongoRepository
public interface IDiscountRepository extends ReactorCrudRepository<Discount, ObjectId> , ReactorJpaSpecificationExecutor<Discount> {
@NonNull
Flux<Page<Discount>> findAll(@Nullable PredicateSpecification<Discount> spec, Pageable pageable);
}
service
public Flux<DiscountModel> find(DiscountFilterModel searchCriteria) {
LOG.info("Find the discount");
var test = Mono.from(iDiscountRepository.findAll(QueryBuilder(searchCriteria), Pageable.from(0, 2))).block();
return iDiscountRepository.findAll(QueryBuilder(searchCriteria), Pageable.from(0,2)).map(item -> this.mapDiscountToModel(item.));
}
Query builder
@Introspected
public record QueryBuilderSpecification() {
public static PredicateSpecification<Discount> QueryBuilder(DiscountFilterModel discountFilterModel){
PredicateSpecification<Discount> predicateSpecification = null;
if (discountFilterModel.getId() != null){
predicateSpecification = DiscountIdEquals(new ObjectId(discountFilterModel.getId()));
}
if (discountFilterModel.getDiscountCode() != null){
predicateSpecification = DiscountCodeEquals(discountFilterModel.getDiscountCode());
}
return predicateSpecification;
}
}
Predicate
public class DiscountSpecification {
final static BeanIntrospection<Discount> introspection = BeanIntrospection.getIntrospection(Discount.class);
static String[] discountProperty = introspection.getPropertyNames();
public static PredicateSpecification<Discount> DiscountIdEquals(ObjectId DiscountId) {
return (root, criteriaBuilder) -> criteriaBuilder.equal(root.get(discountProperty[0]), DiscountId);
}
public static PredicateSpecification<Discount> DiscountCodeEquals(String DiscountCode) {
return (root, criteriaBuilder) -> criteriaBuilder.equal(root.get(discountProperty[1]), DiscountCode);
}
}
Exception
java.lang.ClassCastException: class fete.bird.entities.Discount cannot be cast to class io.micronaut.data.model.Page (fete.bird.entities.Discount and io.micronaut.data.model.Page are in unnamed module of loader 'app')
at fete.bird.service.DiscountService.find(DiscountService.java:30)
at fete.bird.aggregate.query.GetDiscountsQuery$GetDiscountsQueryHandler.handler(GetDiscountsQuery.java:23)
at fete.bird.aggregate.query.GetDiscountsQuery$GetDiscountsQueryHandler.handler(GetDiscountsQuery.java:15)
at fete.bird.utils.ServiceBus.send(ServiceBus.java:27)
at fete.bird.api.v1.controller.DiscountController.find(DiscountController.java:48)
at fete.bird.api.v1.controller.$DiscountController$Definition$Intercepted.$$access$$find(Unknown Source)
at fete.bird.api.v1.controller.$DiscountController$Definition$Exec.dispatch(Unknown Source)
at io.micronaut.context.AbstractExecutableMethodsDefinition$DispatchedExecutableMethod.invoke(AbstractExecutableMethodsDefinition.java:378)
at io.micronaut.aop.chain.MethodInterceptorChain.proceed(MethodInterceptorChain.java:128)
at io.micronaut.validation.ValidatingInterceptor.intercept(ValidatingInterceptor.java:138)
at io.micronaut.aop.chain.MethodInterceptorChain.proceed(MethodInterceptorChain.java:137)
at fete.bird.api.v1.controller.$DiscountController$Definition$Intercepted.find(Unknown Source)
at fete.bird.api.v1.controller.$DiscountController$Definition$Exec.dispatch(Unknown Source)
at io.micronaut.context.AbstractExecutableMethodsDefinition$DispatchedExecutableMethod.invoke(AbstractExecutableMethodsDefinition.java:378)
at io.micronaut.context.DefaultBeanContext$4.invoke(DefaultBeanContext.java:583)
at io.micronaut.web.router.AbstractRouteMatch.execute(AbstractRouteMatch.java:303)
at io.micronaut.web.router.RouteMatch.execute(RouteMatch.java:111)
at io.micronaut.http.context.ServerRequestContext.with(ServerRequestContext.java:103)
at io.micronaut.http.server.RouteExecutor.lambda$executeRoute$14(RouteExecutor.java:659)
at reactor.core.publisher.FluxDeferContextual.subscribe(FluxDeferContextual.java:49)
at reactor.core.publisher.Flux.subscribe(Flux.java:8469)
at reactor.core.publisher.FluxFlatMap$FlatMapMain.onNext(FluxFlatMap.java:426)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onNext(ReactorSubscriber.java:57)
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2398)
at reactor.core.publisher.FluxFlatMap$FlatMapMain.onSubscribe(FluxFlatMap.java:371)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onSubscribe(ReactorSubscriber.java:50)
at reactor.core.publisher.FluxJust.subscribe(FluxJust.java:68)
at reactor.core.publisher.Flux.subscribe(Flux.java:8469)
at reactor.core.publisher.MonoFlatMapMany$FlatMapManyMain.onNext(MonoFlatMapMany.java:195)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onNext(ReactorSubscriber.java:57)
at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:82)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onNext(ReactorSubscriber.java:57)
at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:282)
at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:863)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onNext(ReactorSubscriber.java:57)
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:180)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onNext(ReactorSubscriber.java:57)
at reactor.core.publisher.FluxFilter$FilterSubscriber.onNext(FluxFilter.java:113)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onNext(ReactorSubscriber.java:57)
at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:101)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onNext(ReactorSubscriber.java:57)
at reactor.core.publisher.FluxHide$SuppressFuseableSubscriber.onNext(FluxHide.java:137)
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2398)
at reactor.core.publisher.FluxHide$SuppressFuseableSubscriber.request(FluxHide.java:152)
at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.request(FluxDefaultIfEmpty.java:77)
at reactor.core.publisher.FluxFilter$FilterSubscriber.request(FluxFilter.java:186)
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.request(MonoPeekTerminal.java:139)
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:2194)
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:2068)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onSubscribe(ReactorSubscriber.java:50)
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onSubscribe(MonoPeekTerminal.java:152)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onSubscribe(ReactorSubscriber.java:50)
at reactor.core.publisher.FluxFilter$FilterSubscriber.onSubscribe(FluxFilter.java:85)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onSubscribe(ReactorSubscriber.java:50)
at reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onSubscribe(FluxDefaultIfEmpty.java:91)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onSubscribe(ReactorSubscriber.java:50)
at reactor.core.publisher.FluxHide$SuppressFuseableSubscriber.onSubscribe(FluxHide.java:122)
at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:55)
at reactor.core.publisher.Mono.subscribe(Mono.java:4400)
at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:451)
at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:219)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onSubscribe(ReactorSubscriber.java:50)
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:165)
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:87)
at reactor.core.publisher.InternalFluxOperator.subscribe(InternalFluxOperator.java:62)
at reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:54)
at reactor.core.publisher.Mono.subscribe(Mono.java:4400)
at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:82)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onComplete(ReactorSubscriber.java:71)
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onComplete(MonoFlatMap.java:181)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onComplete(ReactorSubscriber.java:71)
at reactor.core.publisher.MonoNext$NextSubscriber.onComplete(MonoNext.java:102)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onComplete(ReactorSubscriber.java:71)
at reactor.core.publisher.FluxFlatMap$FlatMapMain.checkTerminated(FluxFlatMap.java:846)
at reactor.core.publisher.FluxFlatMap$FlatMapMain.drainLoop(FluxFlatMap.java:608)
at reactor.core.publisher.FluxFlatMap$FlatMapMain.drain(FluxFlatMap.java:588)
at reactor.core.publisher.FluxFlatMap$FlatMapMain.onComplete(FluxFlatMap.java:465)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onComplete(ReactorSubscriber.java:71)
at reactor.core.publisher.FluxIterable$IterableSubscription.slowPath(FluxIterable.java:294)
at reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:230)
at reactor.core.publisher.FluxFlatMap$FlatMapMain.onSubscribe(FluxFlatMap.java:371)
at io.micronaut.reactive.reactor.instrument.ReactorSubscriber.onSubscribe(ReactorSubscriber.java:50)
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:165)
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:87)
at reactor.core.publisher.Flux.subscribe(Flux.java:8469)
at io.micronaut.tracing.brave.instrument.http.HttpServerTracingPublisher.subscribe(HttpServerTracingPublisher.java:85)
at reactor.core.publisher.FluxSource.subscribe(FluxSource.java:67)
at reactor.core.publisher.Flux.subscribe(Flux.java:8469)
at io.micronaut.http.server.netty.RoutingInBoundHandler.handleRouteMatch(RoutingInBoundHandler.java:586)
at io.micronaut.http.server.netty.RoutingInBoundHandler.channelRead0(RoutingInBoundHandler.java:449)
at io.micronaut.http.server.netty.RoutingInBoundHandler.channelRead0(RoutingInBoundHandler.java:144)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
Not able to cast the class, not sure how to fix this one.
Reference - https://micronaut-projects.github.io/micronaut-data/latest/guide/#pagination
This is fixed in the latest version of Micronaut Data 3.4 and will be included in Micronaut 3.5 release.