public class SimpleQueryBus extends Object implements QueryBus
In case multiple handlers are registered for the same query and response type, the query(QueryMessage)
method will invoke one of these handlers. Which one is unspecified.
Modifier and Type | Class and Description |
---|---|
static class |
SimpleQueryBus.Builder
Builder class to instantiate a
SimpleQueryBus . |
Modifier | Constructor and Description |
---|---|
protected |
SimpleQueryBus(SimpleQueryBus.Builder builder)
Instantiate a
SimpleQueryBus based on the fields contained in the SimpleQueryBus.Builder . |
Modifier and Type | Method and Description |
---|---|
static SimpleQueryBus.Builder |
builder()
Instantiate a Builder to be able to create a
SimpleQueryBus . |
protected Map<String,Collection<QuerySubscription<?>>> |
getSubscriptions()
Returns the subscriptions for this query bus.
|
<Q,R> CompletableFuture<QueryResponseMessage<R>> |
query(QueryMessage<Q,R> query)
Dispatch the given
query to a single QueryHandler subscribed to the given query 's queryName and
responseType. |
QueryUpdateEmitter |
queryUpdateEmitter()
Gets the
QueryUpdateEmitter associated with this QueryBus . |
Registration |
registerDispatchInterceptor(MessageDispatchInterceptor<? super QueryMessage<?,?>> interceptor)
Registers an interceptor that intercepts Queries as they are sent.
|
Registration |
registerHandlerInterceptor(MessageHandlerInterceptor<? super QueryMessage<?,?>> interceptor)
Registers an interceptor that is used to intercept Queries before they are passed to their respective handlers.
|
<Q,R> Stream<QueryResponseMessage<R>> |
scatterGather(QueryMessage<Q,R> query,
long timeout,
TimeUnit unit)
Dispatch the given
query to all QueryHandlers subscribed to the given query 's
queryName/responseType. |
<Q,R> org.reactivestreams.Publisher<QueryResponseMessage<R>> |
streamingQuery(StreamingQueryMessage<Q,R> query)
Builds a
Publisher of responses to the given query . |
<R> Registration |
subscribe(String queryName,
Type responseType,
MessageHandler<? super QueryMessage<?,R>> handler)
Subscribe the given
handler to queries with the given queryName and responseType . |
<Q,I,U> SubscriptionQueryResult<QueryResponseMessage<I>,SubscriptionQueryUpdateMessage<U>> |
subscriptionQuery(SubscriptionQueryMessage<Q,I,U> query,
int updateBufferSize)
Dispatch the given
query to a single QueryHandler subscribed to the given query 's
queryName/initialResponseType/updateResponseType. |
<Q,I,U> SubscriptionQueryResult<QueryResponseMessage<I>,SubscriptionQueryUpdateMessage<U>> |
subscriptionQuery(SubscriptionQueryMessage<Q,I,U> query,
SubscriptionQueryBackpressure backpressure,
int updateBufferSize)
Deprecated.
in favor use of {
subscriptionQuery(SubscriptionQueryMessage, int) |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
subscriptionQuery
protected SimpleQueryBus(SimpleQueryBus.Builder builder)
SimpleQueryBus
based on the fields contained in the SimpleQueryBus.Builder
.builder
- the SimpleQueryBus.Builder
used to instantiate a SimpleQueryBus
instancepublic static SimpleQueryBus.Builder builder()
SimpleQueryBus
.
The MessageMonitor
is defaulted to NoOpMessageMonitor
, TransactionManager
to
NoTransactionManager
, QueryInvocationErrorHandler
to LoggingQueryInvocationErrorHandler
,
the SpanFactory
to a NoOpSpanFactory
and QueryUpdateEmitter
to
SimpleQueryUpdateEmitter
.
SimpleQueryBus
public <R> Registration subscribe(@Nonnull String queryName, @Nonnull Type responseType, @Nonnull MessageHandler<? super QueryMessage<?,R>> handler)
QueryBus
handler
to queries with the given queryName
and responseType
.
Multiple handlers may subscribe to the same combination of queryName/responseType.public <Q,R> CompletableFuture<QueryResponseMessage<R>> query(@Nonnull QueryMessage<Q,R> query)
QueryBus
query
to a single QueryHandler subscribed to the given query
's queryName and
responseType. This method returns all values returned by the Query Handler as a Collection. This may or may not
be the exact collection as defined in the Query Handler.
If the Query Handler defines a single return object (i.e. not a collection or array), that object is returned as the sole entry in a singleton collection.
When no handlers are available that can answer the given query
, the returned CompletableFuture will be
completed with a NoHandlerForQueryException
.
public <Q,R> org.reactivestreams.Publisher<QueryResponseMessage<R>> streamingQuery(StreamingQueryMessage<Q,R> query)
QueryBus
Publisher
of responses to the given query
. The actual query is not dispatched until
there is a subscription to the result. The query is dispatched to a single query handler. Implementations may opt
for invoking several query handlers and then choosing a response from single one for performance or resilience
reasons.
When no handlers are available that can answer the given query
, the return Publisher will be completed
with a NoHandlerForQueryException
.
streamingQuery
in interface QueryBus
Q
- the payload type of the streaming queryR
- the response type of the streaming queryquery
- the streaming query messagepublic <Q,R> Stream<QueryResponseMessage<R>> scatterGather(@Nonnull QueryMessage<Q,R> query, long timeout, @Nonnull TimeUnit unit)
QueryBus
query
to all QueryHandlers subscribed to the given query
's
queryName/responseType. Returns a stream of results which blocks until all handlers have processed the request or
when the timeout occurs.
If no handlers are available to provide a result, or when all available handlers throw an exception while attempting to do so, the returned Stream is empty.
Note that any terminal operation (such as Stream.forEach(Consumer)
) on the Stream may cause it to block
until the timeout
has expired, awaiting additional data to include in the stream.
scatterGather
in interface QueryBus
Q
- the payload type of the queryR
- the response type of the queryquery
- the querytimeout
- time to wait for resultsunit
- unit for the timeout@Deprecated public <Q,I,U> SubscriptionQueryResult<QueryResponseMessage<I>,SubscriptionQueryUpdateMessage<U>> subscriptionQuery(@Nonnull SubscriptionQueryMessage<Q,I,U> query, SubscriptionQueryBackpressure backpressure, int updateBufferSize)
subscriptionQuery(SubscriptionQueryMessage, int)
query
to a single QueryHandler subscribed to the given query
's
queryName/initialResponseType/updateResponseType. The result is lazily created and there will be no execution of
the query handler before there is a subscription to the initial result. In order not to miss updates, the query
bus will queue all updates which happen after the subscription query is done and once the subscription to the
flux is made, these updates will be emitted.
If there is an error during retrieving or consuming initial result, stream for incremental updates is NOT interrupted.
If there is an error during emitting an update, subscription is cancelled causing further emits not reaching the destination.
Provided backpressure mechanism will be used to deal with fast emitters.
subscriptionQuery
in interface QueryBus
Q
- the payload type of the queryI
- the response type of the queryU
- the incremental response types of the queryquery
- the querybackpressure
- the backpressure mechanism to be used for emitting updatesupdateBufferSize
- the size of buffer which accumulates updates before subscription to the flux
is
madepublic <Q,I,U> SubscriptionQueryResult<QueryResponseMessage<I>,SubscriptionQueryUpdateMessage<U>> subscriptionQuery(@Nonnull SubscriptionQueryMessage<Q,I,U> query, int updateBufferSize)
QueryBus
query
to a single QueryHandler subscribed to the given query
's
queryName/initialResponseType/updateResponseType. The result is lazily created and there will be no execution of
the query handler before there is a subscription to the initial result. In order not to miss updates, the query
bus will queue all updates which happen after the subscription query is done and once the subscription to the
flux is made, these updates will be emitted.
If there is an error during retrieving or consuming initial result, stream for incremental updates is NOT interrupted.
If there is an error during emitting an update, subscription is cancelled causing further emits not reaching the destination.
subscriptionQuery
in interface QueryBus
Q
- the payload type of the queryI
- the response type of the queryU
- the incremental response types of the queryquery
- the queryupdateBufferSize
- the size of buffer which accumulates updates before subscription to the flux
is
madepublic QueryUpdateEmitter queryUpdateEmitter()
QueryBus
QueryUpdateEmitter
associated with this QueryBus
.queryUpdateEmitter
in interface QueryBus
QueryUpdateEmitter
protected Map<String,Collection<QuerySubscription<?>>> getSubscriptions()
public Registration registerHandlerInterceptor(@Nonnull MessageHandlerInterceptor<? super QueryMessage<?,?>> interceptor)
registerHandlerInterceptor
in interface MessageHandlerInterceptorSupport<QueryMessage<?,?>>
interceptor
- the interceptor to invoke before passing a Query to the handler@Nonnull public Registration registerDispatchInterceptor(@Nonnull MessageDispatchInterceptor<? super QueryMessage<?,?>> interceptor)
registerDispatchInterceptor
in interface MessageDispatchInterceptorSupport<QueryMessage<?,?>>
interceptor
- the interceptor to invoke when sending a QueryCopyright © 2010–2023. All rights reserved.