Spring cassandra数据使得获取分页信息变得容易。但我不能让这个工作。
回购,通话和错误:
1.无功呼叫
回购:
public interface MyRepository extends ReactiveCassandraRepository<MyClass, String> {
@Query("select * from my_keyspace.my_table where solr_query = ?0")
Mono<Slice<MyClass>> findMono(String solrQuery, Pageable page);
}
呼叫:
Mono<Slice<MyClass>> repository.findMono(queryString, CassandraPageRequest.first(20));
错误:
“exceptionDescription”:“org.springframework.core.codec.CodecException:类型定义错误:[simple type,class com.datastax.driver.core.PagingState];嵌套异常是com.fasterxml.jackson.databind.exc.InvalidDefinitionException:没有找到类com.datastax.driver.core.PagingState的序列化程序,也没有发现创建BeanSerializer的属性(为了避免异常,请禁用SerializationFeature.FAIL_ON_EMPTY_BEANS)(通过引用链:org.springframework.data.domain.SliceImpl [\“pageable \ “] - > org.springframework.data.cassandra.core.query.CassandraPageRequest [\” pagingState \ “])”, “行”:[“org.springframework.http.codec.json.AbstractJackson2Encoder.encodeValue(AbstractJackson2Encoder.java :175) “ ”$ org.springframework.http.codec.json.AbstractJackson2Encoder.lambda编码$ 0(AbstractJackson2Encoder.java:122)“,” $ reactor.core.publisher.FluxMap MapSubscriber.onNext(FluxMap.java:100) “ ”reactor.core.publisher.FluxSwitchIfEmpty $ SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)“,” reactor.core.publisher.FluxMap $ MapSubscriber.onNext(FluxMap.java:114) “ ”reactor.core.publisher.FluxDefaultIfEmpty $ DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:92)“,” reactor.core.publisher.Operators $ MonoSubscriber.complete(Operators.java:1476) “ ”reactor.core.publisher.MonoFlatMap $ FlatMapInner.onNext(MonoFlatMap.java:241)“,” reactor.core.publisher.FluxMapFuseable $ MapFuseableSubscriber.onNext(FluxMapFuseable.java: 121) “ ”reactor.core.publisher.Operators $ MonoSubscriber.complete(Operators.java:1476)“, ”reactor.core.publisher.MonoCollectList $ MonoBufferAllSubscriber.onComplete(MonoCollectList.java:118)“,” reactor.core .publisher.FluxTake $ TakeFuseableSubscriber.onComplete(FluxTake.java:424) “ ”reactor.core.publisher.FluxTake $ TakeFuseableSubscriber.onNext(FluxTake.java:404)“,” reactor.core.publisher.FluxIterable $ IterableSubscription.fastPath (FluxIterable.java:311)","reactor.core.publisher.FluxIterable$IterableSubscription.request(FluxIterable.java:198)“],
2.与ReactiveSortingRepository一起使用
回购:
public interface LocationRepository extends ReactiveSortingRepository<MyClass, String> {
}
呼叫:
repository.findAll(CassandraPageRequest.first(20))
错误:
语法错误:findAll不能应用于CassandraPageRequest。
3.简单的调用以获取页面。
回购:
public interface MyRepository extends CassandraRepository<MyClass, MyClassKey> {
Page<MyClass> findByKeyTerminalIdAndSolrQuery(String solrQuery, Pageable page);
}
启动时出错:
引起:org.springframework.dao.InvalidDataAccessApiUsageException:不支持页面查询。使用切片查询。
4.使用PagingAndSortingRepository
回购:
public interface MyRepository extends PagingAndSortingRepository<MyClass, MyClassKey> {
}
呼叫:
Page<Vessel> vessels = repository.findAll(CassandraPageRequest.first(10));
错误:
springframework.data.mapping.PropertyReferenceException:找不到类型MyClass的属性findAll!
欢迎来到Stack Overflow。
第一个例子是合适的例子:
public interface MyRepository extends ReactiveCassandraRepository<MyClass, String> {
@Query("select * from my_keyspace.my_table where solr_query = ?0")
Mono<Slice<MyClass>> findMono(String solrQuery, Pageable page);
}
Mono<Slice<MyClass>> repository.findMono(queryString, CassandraPageRequest.first(20));
问题是杰克逊不能编码SliceImpl
(Slice
的实现),因为你将它传递给WebFlux(根据堆栈跟踪)。所以查询产生了正确的结果,但如果你想对它进行JSON编码,你需要传递Slice
内容,而不是Slice
本身。
在相关的说明:ReactiveCassandraRepository
没有实现ReactiveSortingRepository
,因为使用Sort
参数的Casandra查询总是需要WHERE
子句。看看ReactiveSortingRepository
,你会看到一个不采用过滤标准的findAll(Sort)
方法:
public interface ReactiveSortingRepository<T, ID> extends ReactiveCrudRepository<T, ID> {
Flux<T> findAll(Sort sort);
}