/*
* Copyright 2002-2015 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.integration.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Indicates that a method is capable of resolving to a channel or channel name
* based on a message, message header(s), or both.
* <p>
* A method annotated with @Router may accept a parameter of type
* {@link org.springframework.messaging.Message} or of the expected
* Message payload's type. Any type conversion supported by
* {@link org.springframework.beans.SimpleTypeConverter} will be applied to
* the Message payload if necessary. Header values can also be passed as
* Message parameters by using the
* {@link org.springframework.messaging.handler.annotation.Header @Header} parameter annotation.
* <p>
* Return values from the annotated method may be either a Collection or Array
* whose elements are either
* {@link org.springframework.messaging.MessageChannel channels} or
* Strings. In the latter case, the endpoint hosting this router will attempt
* to resolve each channel name with the Channel Registry or with
* {@link #channelMappings()}, if provided.
*
* @author Mark Fisher
* @author Artem Bilan
*/
@Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface Router {
/**
* Specify the channel from which this router will consume messages.
* If the channel does not exist, a {@code DirectChannel} with this name will be
* registered in the application context.
* @return The channel name.
*/
String inputChannel() default "";
/**
* Specify the channel to which this router will send messages for which destination
* channels are not resolved and {@link #resolutionRequired()} is false.
* @return The channel name.
*/
String defaultOutputChannel() default "";
/**
* The 'key=value' pairs to represent channelMapping entries
* @return the channelMappings.
* @see org.springframework.integration.router.AbstractMappingMessageRouter#setChannelMapping(String, String)
*/
String[] channelMappings() default {};
/**
* Specify a prefix to be added to each channel name prior to resolution.
* @return the prefix.
*/
String prefix() default "";
/**
* Specify a suffix to be added to each channel name prior to resolution.
* @return the suffix.
*/
String suffix() default "";
/**
* Specify whether channel names must always be successfully resolved
* to existing channel instances.
* <p> If set to {@code true} (default), a {@link org.springframework.messaging.MessagingException}
* will be raised in case the channel cannot be resolved. Setting this attribute to {@code false},
* will cause any unresolvable channels to be ignored.
* Can be specified as 'property placeholder', e.g. {@code ${spring.integration.resolutionRequired}}.
* @return the resolution required flag.
*/
String resolutionRequired() default "";
/**
* Specify whether sequence number and size headers should be added to each
* Message. Defaults to {@code false}.
* Can be specified as 'property placeholder', e.g. {@code ${spring.integration.applySequence}}.
* @return the apply sequence flag.
*/
String applySequence() default "";
/**
* If set to {@code true} , failures to send to a message channel will
* be ignored. If set to {@code false} (default), a {@link org.springframework.messaging.MessageDeliveryException}
* will be thrown instead, and if the router resolves more than one channel,
* any subsequent channels will not receive the message.
* Please be aware that when using direct channels (single threaded),
* send-failures can be caused by exceptions thrown by components
* much further down-stream.
* Can be specified as 'property placeholder', e.g. {@code ${spring.integration.ignoreSendFailures}}.
* @return the ignore send failures flag.
*/
String ignoreSendFailures() default "";
/**
* Specify the maximum amount of time in milliseconds to wait when sending a reply
* {@link org.springframework.messaging.Message} to the {@code outputChannel}.
* Defaults to {@code -1} - blocking indefinitely.
* It is applied only if the output channel has some 'sending' limitations, e.g.
* {@link org.springframework.integration.channel.QueueChannel} with
* fixed a 'capacity'. In this case a {@link org.springframework.messaging.MessageDeliveryException} is thrown.
* The 'sendTimeout' is ignored in case of
* {@link org.springframework.integration.channel.AbstractSubscribableChannel} implementations.
* Can be specified as 'property placeholder', e.g. {@code ${spring.integration.sendTimeout}}.
* @return The timeout for sending results to the reply target (in milliseconds)
*/
String sendTimeout() default "";
/**
* The {@link org.springframework.context.SmartLifecycle} {@code autoStartup} option.
* Can be specified as 'property placeholder', e.g. {@code ${foo.autoStartup}}.
* Defaults to {@code true}.
* @return the auto startup {@code boolean} flag.
*/
String autoStartup() default "";
/**
* Specify a {@link org.springframework.context.SmartLifecycle} {@code phase} option.
* Defaults {@code 0} for {@link org.springframework.integration.endpoint.PollingConsumer}
* and {@code Integer.MIN_VALUE} for {@link org.springframework.integration.endpoint.EventDrivenConsumer}.
* Can be specified as 'property placeholder', e.g. {@code ${foo.phase}}.
* @return the {@code SmartLifecycle} phase.
*/
String phase() default "";
/**
* @return the {@link Poller} options for a polled endpoint
* ({@link org.springframework.integration.scheduling.PollerMetadata}).
* This attribute is an {@code array} just to allow an empty default (no poller).
* Only one {@link Poller} element is allowed.
*/
Poller[] poller() default {};
}