org.axonframework.commandhandling

Class AnnotationCommandHandlerAdapter<T>

java.lang.Object

org.axonframework.commandhandling.AnnotationCommandHandlerAdapter<T>

All Implemented Interfaces:

CommandMessageHandler, MessageHandler<CommandMessage<?>>

public class AnnotationCommandHandlerAdapter<T>
extends Object
implements CommandMessageHandler

Adapter that turns any @CommandHandler annotated bean into a MessageHandler implementation. Each annotated method is subscribed as a CommandHandler at the CommandBus for the command type specified by the parameter of that method.

Since:

0.5

Author:

Allard Buijze

See Also:

CommandHandler

Constructor Summary

Constructors

Constructor and Description
AnnotationCommandHandlerAdapter(T annotatedCommandHandler) Wraps the given annotatedCommandHandler, allowing it to be subscribed to a Command Bus.
AnnotationCommandHandlerAdapter(T annotatedCommandHandler, ParameterResolverFactory parameterResolverFactory) Wraps the given annotatedCommandHandler, allowing it to be subscribed to a Command Bus.
AnnotationCommandHandlerAdapter(T annotatedCommandHandler, ParameterResolverFactory parameterResolverFactory, HandlerDefinition handlerDefinition) Wraps the given annotatedCommandHandler, allowing it to be subscribed to a Command Bus.

Method Summary

Modifier and Type	Method and Description
boolean	canHandle(CommandMessage<?> message) Indicates whether this handler can handle the given message
Object	handle(CommandMessage<?> command) Invokes the @CommandHandler annotated method that accepts the given command.
Registration	subscribe(CommandBus commandBus) Subscribe this command handler to the given commandBus.
Set<String>	supportedCommandNames() Returns the set of command names this handler supports.

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.MessageHandler

canHandleType, getTargetType

Constructor Detail

AnnotationCommandHandlerAdapter

public AnnotationCommandHandlerAdapter(T annotatedCommandHandler)

Wraps the given annotatedCommandHandler, allowing it to be subscribed to a Command Bus.

Parameters:

annotatedCommandHandler - The object containing the @CommandHandler annotated methods

AnnotationCommandHandlerAdapter

public AnnotationCommandHandlerAdapter(T annotatedCommandHandler,
                                       ParameterResolverFactory parameterResolverFactory)

Wraps the given annotatedCommandHandler, allowing it to be subscribed to a Command Bus.

Parameters:

annotatedCommandHandler - The object containing the @CommandHandler annotated methods

parameterResolverFactory - The strategy for resolving handler method parameter values

AnnotationCommandHandlerAdapter

public AnnotationCommandHandlerAdapter(T annotatedCommandHandler,
                                       ParameterResolverFactory parameterResolverFactory,
                                       HandlerDefinition handlerDefinition)

Wraps the given annotatedCommandHandler, allowing it to be subscribed to a Command Bus.

Parameters:

annotatedCommandHandler - The object containing the @CommandHandler annotated methods

parameterResolverFactory - The strategy for resolving handler method parameter values

handlerDefinition - The handler definition used to create concrete handlers

Method Detail

subscribe

public Registration subscribe(CommandBus commandBus)

Subscribe this command handler to the given commandBus. The command handler will be subscribed for each of the supported commands.

Parameters:

commandBus - The command bus instance to subscribe to

Returns:

A handle that can be used to unsubscribe

handle

public Object handle(CommandMessage<?> command)
              throws Exception

Invokes the @CommandHandler annotated method that accepts the given command.

Specified by:

handle in interface MessageHandler<CommandMessage<?>>

Parameters:

command - The command to handle

Returns:

the result of the command handling. Is null when the annotated handler has a void return value.

Throws:

NoHandlerForCommandException - when no handler is found for given command.

Exception - any exception occurring while handling the command

canHandle

public boolean canHandle(CommandMessage<?> message)

Description copied from interface: MessageHandler

Indicates whether this handler can handle the given message

Specified by:

canHandle in interface MessageHandler<CommandMessage<?>>

Parameters:

message - The message to verify

Returns:

true if this handler can handle the message, otherwise false

supportedCommandNames

public Set<String> supportedCommandNames()

Description copied from interface: CommandMessageHandler

Returns the set of command names this handler supports.

Specified by:

supportedCommandNames in interface CommandMessageHandler

Returns:

the set of supported command names