Package org.axonframework.extension.reactor.messaging.queryhandling.gateway

Class DefaultReactorQueryGateway

java.lang.Object

org.axonframework.extension.reactor.messaging.queryhandling.gateway.DefaultReactorQueryGateway

All Implemented Interfaces:

DescribableComponent, ReactorQueryGateway

public class DefaultReactorQueryGateway
extends Object
implements ReactorQueryGateway

Default implementation of ReactorQueryGateway.

Builds a recursive interceptor chain that runs inside the Reactor subscription, then delegates to the Axon Framework QueryGateway.

Since:

4.4.2

Author:

Milan Savic, Theo Emanuelsson

See Also:

• ReactorQueryGateway
• ReactorMessageDispatchInterceptor

Constructor Summary

Constructors

Constructor	Description
DefaultReactorQueryGateway(QueryGateway queryGateway, MessageTypeResolver messageTypeResolver)	Instantiate a DefaultReactorQueryGateway without dispatch interceptors.
DefaultReactorQueryGateway(QueryGateway queryGateway, MessageTypeResolver messageTypeResolver, List<ReactorMessageDispatchInterceptor<? super QueryMessage>> dispatchInterceptors)	Instantiate a DefaultReactorQueryGateway.

Method Summary

Modifier and Type	Method	Description
void	describeTo(ComponentDescriptor descriptor)	Describe the properties of this DescribableComponent with the given descriptor.
<R> reactor.core.publisher.Mono<R>	query(Object query, Class<R> responseType, @Nullable ProcessingContext context)	Sends the given query in the provided context (if available) and returns a Mono with a single typed result.
<R> reactor.core.publisher.Mono<List<R>>	queryMany(Object query, Class<R> responseType, @Nullable ProcessingContext context)	Sends the given query in the provided context (if available) and returns a Mono with a list of typed results.
<R> reactor.core.publisher.Flux<R>	streamingQuery(Object query, Class<R> responseType, @Nullable ProcessingContext context)	Sends the given query in the provided context (if available) as a streaming query, returning results as a Flux.
<R> reactor.core.publisher.Flux<R>	subscriptionQuery(Object query, Class<R> responseType, @Nullable ProcessingContext context)	Sends the given query in the provided context (if available) as a subscription query, combining the initial result and subsequent updates as a Flux.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.axonframework.extension.reactor.messaging.queryhandling.gateway.ReactorQueryGateway

query, queryMany, streamingQuery, subscriptionQuery

Constructor Details

DefaultReactorQueryGateway

public DefaultReactorQueryGateway(QueryGateway queryGateway,
 MessageTypeResolver messageTypeResolver,
 List<ReactorMessageDispatchInterceptor<? super QueryMessage>> dispatchInterceptors)

Instantiate a DefaultReactorQueryGateway.

Parameters:

queryGateway - the QueryGateway to delegate query dispatching to

messageTypeResolver - the MessageTypeResolver for resolving message types

dispatchInterceptors - the list of ReactorMessageDispatchInterceptors to apply to queries

DefaultReactorQueryGateway

public DefaultReactorQueryGateway(QueryGateway queryGateway,
 MessageTypeResolver messageTypeResolver)

Instantiate a DefaultReactorQueryGateway without dispatch interceptors.

Parameters:

queryGateway - the QueryGateway to delegate query dispatching to

messageTypeResolver - the MessageTypeResolver for resolving message types

Method Details

query

public <R> reactor.core.publisher.Mono<R> query(Object query,
 Class<R> responseType,
 @Nullable ProcessingContext context)

Description copied from interface: ReactorQueryGateway

Sends the given query in the provided context (if available) and returns a Mono with a single typed result.

Specified by:

query in interface ReactorQueryGateway

Type Parameters:

R - the response type

Parameters:

query - the query payload to send

responseType - the expected response type

context - the processing context, if any, to dispatch the given query in

Returns:

a Mono completing with the query result

queryMany

public <R> reactor.core.publisher.Mono<List<R>> queryMany(Object query,
 Class<R> responseType,
 @Nullable ProcessingContext context)

Description copied from interface: ReactorQueryGateway

Sends the given query in the provided context (if available) and returns a Mono with a list of typed results.

Specified by:

queryMany in interface ReactorQueryGateway

Type Parameters:

R - the element type

Parameters:

query - the query payload to send

responseType - the expected element type

context - the processing context, if any, to dispatch the given query in

Returns:

a Mono completing with a list of query results

streamingQuery

public <R> reactor.core.publisher.Flux<R> streamingQuery(Object query,
 Class<R> responseType,
 @Nullable ProcessingContext context)

Description copied from interface: ReactorQueryGateway

Sends the given query in the provided context (if available) as a streaming query, returning results as a Flux.

Specified by:

streamingQuery in interface ReactorQueryGateway

Type Parameters:

R - the element type

Parameters:

query - the query payload to send

responseType - the expected element type

context - the processing context, if any, to dispatch the given query in

Returns:

a Flux streaming query results

subscriptionQuery

public <R> reactor.core.publisher.Flux<R> subscriptionQuery(Object query,
 Class<R> responseType,
 @Nullable ProcessingContext context)

Description copied from interface: ReactorQueryGateway

Sends the given query in the provided context (if available) as a subscription query, combining the initial result and subsequent updates as a Flux.

Specified by:

subscriptionQuery in interface ReactorQueryGateway

Type Parameters:

R - the response type

Parameters:

query - the query payload to send

responseType - the response type for both initial result and updates

context - the processing context, if any, to dispatch the given query in

Returns:

a Flux streaming the initial result followed by updates

describeTo

public void describeTo(ComponentDescriptor descriptor)

Description copied from interface: DescribableComponent

Describe the properties of this DescribableComponent with the given descriptor.

Components should call the appropriate describeProperty methods on the descriptor to register their properties. The descriptor is responsible for determining how these properties are formatted and structured in the final output.

Best Practices: As a general rule, all relevant fields of a DescribableComponent implementation should be described in this method. However, developers have discretion to include only the fields that make sense in the context. Not every field may be meaningful for description purposes, especially internal implementation details. Furthermore, components might want to expose different information based on their current state. The final decision on what properties to include lies with the person implementing the describeTo method, who should focus on providing information that is useful for understanding the component's configuration and state.

Example implementation:

 public void describeTo(ComponentDescriptor descriptor) {
     descriptor.describeProperty("name", this.name);
     descriptor.describeProperty("enabled", this.enabled);
     descriptor.describeProperty("configuration", this.configuration); // A nested component
     descriptor.describeProperty("handlers", this.eventHandlers);      // A collection
 }
 

Specified by:

describeTo in interface DescribableComponent

Parameters:

descriptor - The component descriptor to describe this DescribableComponentn its properties in.