Package org.axonframework.messaging.commandhandling.gateway

Class DefaultCommandGateway

java.lang.Object

org.axonframework.messaging.commandhandling.gateway.DefaultCommandGateway

All Implemented Interfaces:

DescribableComponent, CommandGateway

public class DefaultCommandGateway
extends Object
implements CommandGateway

Default implementation of the CommandGateway interface.

Since:

2.0.0

Author:

Allard Buijze

Constructor Summary

Constructors

Constructor	Description
DefaultCommandGateway(CommandBus commandBus, MessageTypeResolver messageTypeResolver, CommandPriorityCalculator priorityCalculator, RoutingStrategy routingKeyResolver)	Initialize the DefaultCommandGateway to send commands through given commandBus.

Method Summary

Modifier and Type	Method	Description
void	describeTo(ComponentDescriptor descriptor)	Describe the properties of this DescribableComponent with the given descriptor.
CommandResult	send(Object command, Metadata metadata, ProcessingContext context)	Sends the given command with the given metadata in the provided context (if available) and returns a CommandResult immediately, without waiting for the command to execute.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.messaging.commandhandling.gateway.CommandGateway

send, send, send, send, send, sendAndWait, sendAndWait, sendAndWait, sendAndWait

Constructor Details

DefaultCommandGateway

public DefaultCommandGateway(@Nonnull
 CommandBus commandBus,
 @Nonnull
 MessageTypeResolver messageTypeResolver,
 @Nonnull
 CommandPriorityCalculator priorityCalculator,
 @Nonnull
 RoutingStrategy routingKeyResolver)

Initialize the DefaultCommandGateway to send commands through given commandBus.

The names for CommandMessages are resolved through the given nameResolver.

Parameters:

commandBus - The CommandBus to send commands on.

messageTypeResolver - The MessageTypeResolver resolving the names for CommandMessages being dispatched on the commandBus.

priorityCalculator - The CommandPriorityCalculator determining the priority of commands.

routingKeyResolver - The RoutingStrategy determining the routing key for commands.

Method Details

send

@Nonnull
public CommandResult send(@Nonnull
 Object command,
 @Nonnull
 Metadata metadata,
 @Nullable
 ProcessingContext context)

Description copied from interface: CommandGateway

Sends the given command with the given metadata in the provided context (if available) and returns a CommandResult immediately, without waiting for the command to execute.

The caller will therefore not receive any immediate feedback on the command's execution. Instead, hooks can be added to the returned CommandResult to react on success or failure of command execution. A shorthand to retrieve a CompletableFuture is available through the CommandResult.getResultMessage() operation.

Note that this operation expects the CommandBus to use new threads for command execution.

The given command and metadata are wrapped as the payload of the CommandMessage that is eventually posted on the CommandBus, unless the command already implements Message. In that case, a CommandMessage is constructed from that message's payload and Metadata. The provided metadata is attached afterward in this case.

Specified by:

send in interface CommandGateway

Parameters:

command - The command payload or CommandMessage to send.

metadata - Meta-data that must be registered with the command.

context - The processing context, if any, to dispatch the given command in.

Returns:

A command result success and failure hooks can be registered. The CommandResult.getResultMessage() serves as a shorthand to retrieve the response.

describeTo

public void describeTo(@Nonnull
 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.