1. What's new in Spring Integration 4.0?
This chapter provides an overview of the new features and improvements that have been introduced with Spring Integration 4.0. If you are interested in more details, please see the Issue Tracker tickets that were resolved as part of the 4.0 development process.
Please be sure to also see the Migration Guide for important changes that might affect your applications. Migration guides for all versions back to 2.1 can be found on the Wiki.
The @EnableIntegration annotation has been added, to permit declaration of standard Spring Integration beans when using @Configuration classes. See Section 2.5, "Configuration" for more information.
The @IntegrationComponentScan annotation has been added, to permit classpath scanning for Spring Integration specific components. See Section 2.5, "Configuration" for more information.
Message history can now be enabled with the @EnableMessageHistory annotation in a @Configuration class; in addition the message history settings can be modified by a JMX MBean. In addition auto-created MessageHandlers for annotated endpoints (e.g. @ServiceActivator, @Splitter etc.) now are also trackable by MessageHistory. For more information, see Section 8.2, "Message History".
Messaging gateway interfaces can now be configured with the @MessagingGateway annotation. It is an analogue of the <int:gateway/> xml element. For more information, see Section 7.2.6, "@MessagingGateway Annotation".
As well as the @EnableIntegration annotation mentioned above, a a hook has been introduced to allow the Spring Integration infrastructure beans to be configured using Spring Boot's @EnableAutoConfiguration. For more information see Spring Boot - AutoConfigure.
As well as the @EnableIntegration annotation mentioned above, the @GlobalChannelInterceptor annotation has bean introduced. For more information, see Section 2.5, "Configuration".
The @IntegrationConverter annotation has bean introduced, as an analogue of <int:converter/> component. For more information, see Section 2.5, "Configuration".
The @EnablePublisher annotation has been added, to allow the specification of a default-publisher-channel for @Publisher annotations. See Section 2.5, "Configuration" for more information.
A new Redis MessageGroupStore, that is optimized for use when backing a QueueChannel for persistence, is now provided. For more information, see Section 23.4.1, "Redis Channel Message Stores".
A new Redis ChannelPriorityMessageStore is now provided. This can be used to retrieve messages by priority. For more information, see Section 23.4.1, "Redis Channel Message Stores".
MongoDB support now provides the MongoDbChannelMessageStore - a channel specific MessageStore implementation. With priorityEnabled = true, it can be used in <int:priority-queue>s to achieve priority order polling of persisted messages. For more information see Section 21.3.1, "MongodDB Channel Message Store".
The IntegrationMBeanExporter can now be enabled with the @EnableIntegrationMBeanExport annotation in a @Configuration class. For more information, see Section 8.1.7, "MBean Exporter".
Configuration of Spring Security for message channels using @Configuration classes is now supported by using a ChannelSecurityInterceptorFactoryBean. For more information, see Appendix D, Security in Spring Integration.
The Redis support now provides the <outbound-gateway> component to perform generic Redis commands using the RedisConnection#execute method. For more information, see Section 23.8, "Redis Outbound Command Gateway".
The RedisLockRegistry and GemfireLockRegistry are now available supporting global locks visible to multiple application instances/servers. These can be used with aggregating message handlers across multiple application instances such that group release will occur on only one instance. For more information, see Section 23.9, "Redis Lock Registry", Section 15.6, "Gemfire Lock Registry" and Section 5.4, "Aggregator".
Annotation-based messaging configuration can now have a poller attribute. This means that methods annotated with (@ServiceActivator, @Aggregator etc.) can now use an inputChannel that is a reference to a PollableChannel. For more information, see Section F.5, "Annotation Support".
The @InboundChannelAdapter method annotation is now available. It is an analogue of the <int:inbound-channel-adapter> XML component. In addition, all Messaging Annotations now provide SmartLifecycle options. For more information, see Section F.5, "Annotation Support".
A new twitter endpoint <int-twitter-search-outbound-gateway/> has been added. Unlike the search inbound adapter which polls using the same search query each time, the outbound gateway allows on-demand customized queries. For more information, see Section 30.6, "Twitter Search Outbound Gateway".
The GemfireMetadataStore is provided, allowing it to be used, for example, in a AbstractPersistentAcceptOnceFileListFilter implementation in a multiple application instance/server environment. For more information, see Section 8.4, "Metadata Store", Section 13.2, "Reading Files", Section 14.3, "FTP Inbound Channel Adapter" and Section 26.5, "SFTP Inbound Channel Adapter".
Core messaging abstractions (Message, MessageChannel etc) have moved to the Spring Framework spring-messaging module. Users who reference these classes directly in their code will need to make changes as described in the first section of the Migration Guide.
The header-type attribute has been introduced for the header sub-element of the <int-xml:xpath-header-enricher>. This attribute provides the target type for the header value to which the result of the XPath expression evaluation will be converted. For more information see Section 32.7, "XPath Header Enricher".
The result-type attribute has been introduced for the <int:object-to-json-transformer>. This attribute provides the target type for the result of object mapping to JSON. It supports STRING (default) and NODE. For more information see the section called "Configuring Transformer with XML".
The DefaultJmsHeaderMapper now maps an incoming JMSPriority header to the Spring Integration priority header. Previously priority was only considered for outbound messages. For more information see Section 19.6, "Mapping Message Headers to/from JMS Message".
The JMS outbound channel adapter now supports the session-transacted attribute (default false). Previously, you had to inject a customized JmsTemplate to use transactions. See Section 19.3, "Outbound Channel Adapter".
The JMS inbound channel adapter now supports the session-transacted attribute (default false). Previously, you had to inject a customized JmsTemplate to use transactions (the adapter allowed 'transacted' in the acknowledgeMode which was incorrect, and didn't work; this value is no longer allowed). See Section 19.1, "Inbound Channel Adapter".
You can now specify a MessageConverter to be used when converting (if necessary) payloads to one of the accepted datatypes in a Datatype channel. For more information see the section called "Datatype Channel Configuration".
Simplified namespace support has been added to configure a RequestHandlerRetryAdvice. For more information see the section called "Configuring the Retry Advice".
The mutually exclusive group-timeout and group-timeout-expression attributes have been added to the <int:aggregator> and <int:resequencer>. These attributes allow forced completion of a partial MessageGroup, if the ReleaseStrategy does not release a group and no further messages arrive within the time specified. For more information see Section 5.4.4, "Configuring an Aggregator".
The RedisMetadataStore now implements ConcurrentMetadataStore, allowing it to be used, for example, in a AbstractPersistentAcceptOnceFileListFilter implementation in a multiple application instance/server environment. For more information, see Section 23.5, "Redis Metadata Store", Section 13.2, "Reading Files", Section 14.3, "FTP Inbound Channel Adapter" and Section 26.5, "SFTP Inbound Channel Adapter".
The JdbcChannelMessageStore now implements PriorityCapableChannelMessageStore, allowing it to be used as a message-store reference for priority-queues. For more information, see Section 17.4.2, "Backing Message Channels".
Spring AMQP, by default, creates persistent messages on the broker. This behavior can be overridden by setting the amqp_deliveryMode header and/or customizing the mappers. A convenient default-delivery-mode attribute has now been added to the adapters to provide easier configuration of this important setting. For more information, see Section 10.3, "Outbound Channel Adapter" and Section 10.5, "Outbound Gateway".