For an overview of the changes in Spring Integration 4.0 since version 3.0, please see Chapter 1, What's new in Spring Integration 4.0?.
				The HTTP module now provides powerful Request Mapping support for Inbound Endpoints. Class UriPathHandlerMapping
				was replaced by IntegrationRequestMappingHandlerMapping, which is registered under the bean name
				integrationRequestMappingHandlerMapping in the application context. Upon parsing of the HTTP Inbound Endpoint,
				a new IntegrationRequestMappingHandlerMapping bean is either registered or an existing bean is being reused.
				To achieve flexible Request Mapping configuration, Spring Integration provides the <request-mapping/>
				sub-element for the <http:inbound-channel-adapter/> and the <http:inbound-gateway/>.
				Both HTTP Inbound Endpoints are now fully based on the Request Mapping infrastructure that was introduced with Spring MVC 3.1.
				For example, multiple paths are supported on a single inbound endpoint.
				For more information see Section 16.4, “HTTP Namespace Support”.
			
				A new IntegrationEvaluationContextFactoryBean is provided to allow
				configuration of custom PropertyAccessors and functions for
				use in SpEL expressions throughout the framework. For more information see Appendix A, Spring Expression Language (SpEL).
			
				To customize the SpEL EvaluationContext with static
				Method functions, the new <spel-function/>
				component is introduced. Two built-in functions are also provided (#jsonPath
				and #xpath). For more information see Section A.3, “SpEL Functions”.
			
				To customize the SpEL EvaluationContext with
				PropertyAccessor implementations
				the new <spel-property-accessors/> component is introduced.
				For more information see Section A.4, “PropertyAccessors”.
			
				A new Redis-based
				MetadataStore
				implementation has been added. The RedisMetadataStore can
				be used to maintain state of a MetadataStore
				across application restarts. This new MetadataStore
				implementation can be used with adapters such as:
			
				New queue-based components have been added. The <int-redis:queue-inbound-channel-adapter/>
				and the	<int-redis:queue-outbound-channel-adapter/> components are provided
				to perform 'right pop' and 'left push' operations on a Redis List, respectively.
			
For more information see Chapter 22, Redis Support.
				It is now possible to instruct the framework to store reply and error channels
				in a registry for later resolution. This is useful for cases where
				the replyChannel or errorChannel might be lost; for example
				when serializing
				a message. See Section 6.2.2, “Header Enricher” for more information.
			
				In addition to the existing eMongoDbMessageStore, a new
				ConfigurableMongoDbMessageStore has been introduced.
				This provides a more robust and flexible implementation of MessageStore
				for MongoDB.
				It does not have backward compatibility, with the existing store,
				but it is recommended to use it for new applications. Existing applications can use it, but messages
				in the old store will not be available.
				See Chapter 21, MongoDb Support for more information.
			
				Building on the 2.2 SyslogToMapTransformer Spring
				Integration 3.0 now introduces
				UDP and TCP inbound channel adapters especially tailored
				for receiving SYSLOG messages. For more information, see
				Chapter 27, Syslog Support.
			
File 'tail'ing inbound channel adapters are now provided to generate messages when lines are added to the end of text files; see Section 13.2.1, “'Tail'ing Files”.
<int-jmx:tree-polling-channel-adapter/> is provided; this
						adapter queries the JMX MBean tree and sends a message with a payload that is the
						graph of objects that matches the query. By default the MBeans are mapped to
						primitives and simple Objects like Map, List and arrays - permitting simple
						transformation, for example, to JSON.
					IntegrationMBeanExporter now allows the configuration of
						a custom ObjectNamingStrategy using the naming-strategy
						attribute.
					
For more information, see Section 8.1, “JMX Support”.
				TcpConnections now emit
				ApplicationEvents (specifically
				TcpConnectionEvents) when connections are
				opened, closed, or an exception occurs. This allows applications
				to be informed of changes to TCP connections using the normal
				Spring ApplicationListener
				mechanism.
			
				AbstractTcpConnection has been renamed
				TcpConnectionSupport; custom connections that
				are subclasses of this class, can use its methods to publish events.
				Similarly, AbstractTcpConnectionInterceptor has
				been renamed to TcpConnectionInterceptorSupport.
			
				In addition, a new <int-ip:tcp-connection-event-inbound-channel-adapter/>
				is provided; by default, this adapter sends all TcpConnectionEvents
				to a Channel.
			
				Further, the TCP Connection Factories, now provide a new method
				getOpenConnectionIds(), which returns a list of identifiers for all
				open connections; this allows applications, for example, to broadcast to all
				open connections.
			
				Finally, the connection factories also provide a new method
				closeConnection(String connectionId) which allows applications
				to explicitly close a connection using its ID.
			
For more information see Section 28.5, “TCP Connection Events”.
				The <int:inbound-channel-adapter/> now supports <expression/>
				and <script/> sub-elements to create a
				MessageSource; see Section 3.3.3, “Channel Adapter Expressions and Scripts”.
			
				The Content Enricher now provides configuration for <header/>
				sub-elements, to enrich the outbound Message with headers based on the reply Message from the underlying
				message flow. For more information see Section 6.2.3, “Payload Enricher”.
			
				Previously, message ids were generated using the JDK UUID.randomUUID() method. With this
				release, the default mechanism has been changed to use a more efficient algorithm which
				is significantly faster. In addition, the ability to change
				the strategy used to generate message ids has been added.
				For more information see the section called “Message ID Generation”.
			
GatewayMethodMetadata is now public class and it makes possible flexibly
						to configure the GatewayProxyFactoryBean programmatically from Java code.
					
For more information see Section 7.2, “Messaging Gateways”.
<http:outbound-gateway/>
						and <http:outbound-channel-adapter/> now
						provide an encode-uri attribute to allow disabling the encoding of the URI object
						before sending the request.
					<http:inbound-gateway/> and <http:inbound-channel-adapter/> now
						have a merge-with-default-converters attribute to include the list of default
						HttpMessageConverters after the custom message converters.
					DefaultHttpHeaderMapper.
						Now, in addition correcting that issue, DefaultHttpHeaderMapper provides
						date parsing from formatted strings for any HTTP headers that accept date-time values.
					<http:inbound-gateway/> and <http:inbound-channel-adapter/>
						now support additional useful variables: #matrixVariables, #requestAttributes,
						#requestHeaders and #cookies. These variables are available in
						both payload and header expressions.
					uri-variables-expression attribute to specify
						an Expression to evaluate a Map
						for all URI variable placeholders within URL template. This allows selection of a different
						map of expressions based on the outgoing message.
					
For more information see Chapter 16, HTTP Support.
ObjectToJsonTransformer and JsonToObjectTransformer
						now emit/consume headers containing type information.
					
For more information, see 'JSON Transformers' in Section 6.1, “Transformer”.
				Previously, the id attribute for elements within a <chain> was
				ignored and, in some cases, disallowed. Now, the id attribute is allowed
				for all elements within a <chain>. The bean names of chain elements is a combination
				of the surrounding chain's id and the id of the element
				itself. For example: 'fooChain$child.fooTransformer.handler'.
				For more information see Section 5.6, “Message Handler Chain”.
			
				The AbstractCorrelatingMessageHandler provides a new property
				empty-group-min-timeout
				to allow empty group expiry to run on a longer schedule than expiring partial groups. Empty groups will
				not be removed from the MessageStore until they have not been modified
				for at least this number of milliseconds. For more information see Section 5.4.4, “Configuring an Aggregator”.
			
				New FileListFilters that use a persistent MetadataStore are
				now available. These can be used to prevent duplicate files after a system restart. See
				Section 13.2, “Reading Files”, Section 14.3, “FTP Inbound Channel Adapter”, and Section 25.5, “SFTP Inbound Channel Adapter” for more information.
			
				A new variables attribute has been introduced for scripting components.
				In addition, variable bindings are now allowed for inline scripts.
				See Section 7.6, “Groovy support” and Section 7.5, “Scripting support” for more information.
			
				Previously, when configuring LoadBalancingStrategy on the channel's 'dispatcher' sub-element,
				the only available option was to use a pre-defined enumeration of values which did not allow one to set a custom implementation
				of the LoadBalancingStrategy. You can now use load-balancer-ref to provide
				a reference to a custom implementation of the LoadBalancingStrategy.
				For more information see the section called “DirectChannel”.
			
				Previously, sending to a <publish-subscribe-channel/> that had
				no subscribers would return a false result. If used in conjunction with
				a MessagingTemplate, this would result in an exception being thrown.
				Now, the PublishSubscribeChannel has a property
				minSubscribers (default 0). If the message is sent to at least the minimum
				number of subscribers, the send is deemed to be successful (even if zero). If an application
				is expecting to get an exception under these conditions, set the minimum subscribers to at
				least 1.
			
The FTP, SFTP and FTPS endpoints no longer cache sessions by default
				The deprecated cached-sessions attribute has been removed from all endpoints.
				Previously, the embedded caching mechanism controlled by this attribute's value didn't
				provide a way to limit the size of the cache, which could
				grow indefinitely. The CachingConnectionFactory was introduced in
				release 2.1 and it became the preferred (and is now the only) way to cache sessions.
			
				The CachingConnectionFactory now provides a new method
				resetCache(). This immediately closes idle sessions and causes in-use
				sessions to be closed as and when they are returned to the cache.
			
				The DefaultSftpSessionFactory (in conjunction with a
				CachingSessionFactory) now supports multiplexing channels over
				a single SSH connection (SFTP Only).
			
FTP, SFTP and FTPS Inbound Adapters
				Previously, there was no way to override the default filter used to process files retrieved
				from a remote server. The filter attribute determines which files are retrieved
				but the FileReadingMessageSource uses an
				AcceptOnceFileListFilter. This means that if a new copy of a file
				is retrieved, with the same name as a previously copied file, no message was sent from the
				adapter.
			
				With this release, a new attribute local-filter allows you to override the
				default filter, for example with an AcceptAllFileListFilter, or some
				other custom filter.
			
				For users that wish the behavior of the AcceptOnceFileListFilter
				to be maintained across JVM executions, a custom filter that retains state, perhaps on
				the file system, can now be configured.
			
				Inbound Channel Adapters now support the preserve-timestamp attribute, which
				sets the local file modified timestamp to the timestamp from the server (default false).
			
FTP, SFTP and FTPS Gateways
local-filename-generator-expression attribute is now supported,
						enabling the naming of local files during retrieval. By default, the same
						name as the remote file is used.
					local-directory-expression attribute is now supported,
						enabling the naming of local directories during retrieval based on the remote directory.
					
Remote File Template
				A new higher-level abstraction (RemoteFileTemplate) is provided over the
				Session implementations used by the FTP and SFTP modules. While it is
				used internally by endpoints, this abstraction can also be used programmatically and, like all
				Spring *Template implementations, reliably closes the underlying session while allowing
				low level access to the session when needed.
			
For more information, see Chapter 14, FTP/FTPS Adapters and Chapter 25, SFTP Adapters.
				All Outbound Gateways (e.g. <jdbc:outbound-gateway/> or <jms:outbound-gateway/>)
				are designed for 'request-reply' scenarios. A response is expected from the external service and
				will be published to the reply-channel, or the replyChannel message header.
				However, there are some cases where the external system might not always return a
				result, e.g. a <jdbc:outbound-gateway/>, when a SELECT ends with an empty ResultSet
				or, say, a Web Service is One-Way. An option is therefore needed to configure whether or not a
				reply is required.
				For this purpose, the requires-reply attribute has been introduced for Outbound Gateway components.
				In most cases, the default value for requires-reply is true and, if there is not any result,
				a ReplyRequiredException will be thrown. Changing the value to false
				means that, if an external service doesn't return anything, the message-flow will end at that point,
				similar to an Outbound Channel Adapter.
			
| ![[Note]](images/note.png) | Note | 
|---|---|
| The WebService outbound gateway has an additional attribute ignore-empty-responses; this is used to
				treat an empty String response as if no response was received. It is true by default but can be set to false to
				allow the application to receive an empty String in the reply message payload. When the attribute is true an empty
				string is treated as no response for the purposes of the requires-reply attribute.
				requires-reply is false by default for the WebService outbound gateway. | 
				Note, the requiresReply property was previously present in the AbstractReplyProducingMessageHandler
				but set to false, and there wasn't any way to configure it on Outbound Gateways using the XML namespace.
			
| ![[Important]](images/important.png) | Important | 
|---|---|
| Previously, a gateway receiving no reply would silently end the flow (with a DEBUG log message); with this change an
				exception will now be thrown by default by most gateways. To revert to the previous behavior,
				set requires-replyto false. | 
				Previously, the <int-amqp:outbound-gateway/> mapped headers before invoking the message
				converter, and the converter could overwrite headers such as content-type. The
				outbound adapter maps the headers after the conversion, which means headers like
				content-type from the outbound Message (if present) are used.
			
				Starting with this release, the gateway now maps the headers after the message conversion,
				consistent with the adapter. If your application relies on the previous behavior (where the
				converter's headers overrode the mapped headers), you either need to filter those headers
				(before the message reaches the gateway)
				or set them appropriately. The headers affected by the SimpleMessageConverter
				are content-type and content-encoding. Custom message converters
				may set other headers.
			
				For more complex database-specific types, not supported by the standard
				CallableStatement.getObject method, 2 new additional
				attributes were introduced to the <sql-parameter-definition/>
				element with OUT-direction:
			
					The row-mapper attribute of the Stored Procedure Inbound Channel Adapter
					<returning-resultset/> sub-element
					now supports a reference to a RowMapper bean
					definition. Previously, it contained just a class name (which is still supported).
				
For more information see Section 17.5, “Stored Procedures”.
				Web Service Outbound Gateway 'uri' attribute now supports <uri-variable/> substitution for all
				URI-schemes supported by Spring Web Services. For more information see Section 30.4, “Outbound URI Configuration”.
			
null value for serializer
						property, with the raw data being the message payload.
					topic-expression property to determine
						the Redis topic against the Message at runtime.
					topics attribute,
						now has the topic-patterns attribute.
					
For more information, see Chapter 22, Redis Support.
				Previously, when a <filter/> had a <request-handler-advice-chain/>, the discard
				action was all performed within the scope of the advice chain (including any downstream flow
				on the discard-channel). The filter element now has an attribute
				discard-within-advice (default true), to allow the discard action to
				be performed after the advice chain completes. See Section 7.7.4, “Advising Filters”.
			
Request Handler Advice Chains can now be configured using annotations. See Section 7.7.5, “Advising Endpoints Using Annotations”.
				This transformer now correctly transforms byte[] and char[]
				payloads to String. For more information see Section 6.1, “Transformer”.
			
				Payloads to persist or
				merge can now be of type
				java.lang.Iterable.
			
				In that case, each object returned by the
				Iterable is treated as
				an entity and persisted or merged using the underlying
				EntityManager.
				NULL values returned by the iterator are ignored.
			
The JPA adapters now have additional attributes to optionally 'flush' and 'clear' entities from the associated persistence context after performing persistence operations.
				Retrieving gateways had no mechanism to specify the first record to be retrieved which
				is a common use case. The retrieving gateways now support specifying this parameter
				using a first-result and first-result-expression attributes
				to the gateway definition. Section 18.6.3, “Retrieving Outbound Gateway”.
			
				The JPA retrieving gateway and inbound adapter now have an attribute to specify the maximum
				number of results in a result set as an expression. In addition, the
				max-results attribute has been introduced to replace
				max-number-of-results, which has been deprecated.
				max-results and max-results-expression
				are used to provide the maximum number of results,
				or an expression to compute the maximum number of results, respectively, in the
				result set.
			
For more information see Chapter 18, JPA Support.
				Previously, the <delayer> provided a delay-header-name attribute
				to determine the delay value at runtime. In complex cases it was necessary
				to precede the <delayer> with a <header-enricher>.
				Spring Integration 3.0 introduced the expression attribute and expression
				sub-element for dynamic delay determination. The delay-header-name attribute is now deprecated
				because the header evaluation can be specified in the expression. In addition,
				the ignore-expression-failures was introduced to control the behavior when an
				expression evaluation fails.
				For more information see Section 7.4, “Delayer”.
			
Spring Integration 3.0 adds a new set of DDL scripts for MySQL version 5.6.4 and higher. Now MySQL supports fractional seconds and is thus improving the FIFO ordering when polling from a MySQL-based Message Store. For more information, please see Section 17.4.1, “The Generic JDBC Message Store”.
				Previously, if an IMAP idle connection failed, it was logged but there was no mechanism to
				inform an application. Such exceptions now generate ApplicationEvents.
				Applications can obtain these events using an <int-event:inbound-channel-adapter>
				or any ApplicationListener configured to receive an
				ImapIdleExceptionEvent or one of its super classes.
			
				The TCP connection factories now enable the configuration of a flexible mechanism to
				transfer selected headers (as well as the payload) over TCP. A new
				TcpMessageMapper
				enables the selection of the headers, and an appropriate (de)serializer needs to be
				configured to write the resulting Map to the
				TCP stream. A MapJsonSerializer is provided as a convenient
				mechanism to transfer headers and payload over TCP.
				For more information see Section 28.8.4, “Transferring Headers”.
			
				Previously, when configuring a <message-driven-channel-adapter/>, if you wished to
				use a specific TaskExecutor, it was necessary to declare a container
				bean and provide it to the adapter using the container attribute. The
				task-executor is now provided, allowing it to be set directly on the adapter. This is
				in addition to several other container attributes that were already available.
			
				The RMI Inbound Gateway now supports an error-channel attribute. See
				Section 24.3, “Inbound RMI”.
			
				You can now specify the transformer factory class name using the
				transformer-factory-class attribute. See the section called “XsltPayloadTransformer”
			
Spring Integration now has RedisStore Inbound and Outbound Channel Adapters allowing you to write and read Message payloads to/from Redis collection(s). For more information please see Section 22.7, “RedisStore Outbound Channel Adapter” and Section 22.6, “RedisStore Inbound Channel Adapter”.
Spring Integration now has MongoDB Inbound and Outbound Channel Adapters allowing you to write and read Message payloads to/from a MongoDB document store. For more information please see Section 21.5, “MongoDB Outbound Channel Adapter” and Section 21.4, “MongoDB Inbound Channel Adapter”.
Spring Integration now includes components for the Java Persistence API (JPA) for retrieving and persisting JPA entity objects. The JPA Adapter includes the following components:
For more information please see Chapter 18, JPA Support
The ability to add an <advice-chain/> to a poller has been available for some time. However, the behavior added by this affects the entire integration flow. It did not address the ability to add, say, retry, to an individual endpoint. The 2.2. release introduces the <request-handler-advice-chain/> to many endpoints.
In addition, 3 standard Advice classes have been provided for this purpose:
For more information, see Section 7.7, “Adding Behavior to Endpoints”.
Pollers can now participate in Spring's Transaction Synchronization feature. This allows for synchronizing such operations as renaming files by an inbound channel adapter depending on whether the transaction commits, or rolls back.
				In addition, these features can be enabled when there is not a 'real' transaction present,
				by means of a PseudoTransactionManager.
			
For more information see Section C.3, “Transaction Synchronization”.
When using the File Oubound Channel Adapter or the File Outbound Gateway, a new mode property was added. Prior to Spring Integration 2.2, target files were replaced when they existed. Now you can specify the following options:
For more information please see Section 13.3.3, “Dealing with Existing Destination Files”.
The XML Namespace support adds the reply-timeout attribute to the following Outbound Gateways:
Spring Integration now uses Spring AMQP 1.1. This enables several features to be used within a Spring Integration application, including...
SpEL Support
When using the Stored Procedure components of the Spring Integration JDBC Adapter, you can now provide Stored Procedure Names or Stored Function Names using Spring Expression Language (SpEL).
This allows you to specify the Stored Procedures to be invoked at runtime. For example, you can provide Stored Procedure names that you would like to execute via Message Headers. For more information please see Section 17.5, “Stored Procedures”.
JMX Support
The Stored Procedure components now provide basic JMX support, exposing some of their properties as MBeans:
When using the JDBC Outbound Gateway, the update query is no longer mandatory. You can now provide solely a select query using the request message as a source of parameters.
A new Message Channel-specific Message Store Implementation has been added, providing a more scalable solution using database-specific SQL queries. For more information please see: Section 17.4.2, “Backing Message Channels”.
				A method stopActiveComponents() has been
				added to the IntegrationMBeanExporter. This allows a Spring Integration
				application to be shut down in an orderly manner, disallowing new inbound
				messages to certain adapters and waiting for some time to allow in-flight
				messages to complete.
			
				The JMS Outbound Gateway can now be configured to use a
				MessageListener container to receive
				replies. This can improve performance of the gateway.
			
				The ObjectToJsonTransformer now sets the
				content-type header to application/json
				by default. For more information see Section 6.1, “Transformer”.
			
			   Java serialization over HTTP is no longer enabled by default. Previously, when
			   setting a expected-response-type to a Serializable
			   object, the Accept header was not properly set up. The
			   SerializingHttpMessageConverter has now been updated
			   to set the Accept header to application/x-java-serialized-object.
			   However, because this could cause incompatibility with existing applications,
			   it was decided to no longer automatically add this converter to the HTTP endpoints.
			
			   If you wish to use Java serialization, you will need to add the
			   SerializingHttpMessageConverter to the appropriate
			   endpoints, using the message-converters attribute, when using
			   XML configuration, or using the setMessageConverters() method.
			
			   Alternatively, you may wish to consider using JSON instead which is enabled
			   by simply having Jackson on the classpath.
			
In Spring Integration 2.0, support for Groovy was added. With Spring Integration 2.1 we expanded support for additional languages substantially by implementing support for JSR-223 (Scripting for the Java™ Platform). Now you have the ability to use any scripting language that supports JSR-223 including:
For further details please see Section 7.5, “Scripting support”.
		        Spring Integration provides support for
		        GemFire by providing
		        inbound adapters for entry and continuous query events, an outbound
		        adapter to write entries to the cache, and
		        
		            MessageStore and
		        
		            MessageGroupStore
		        implementations. Spring integration leverages
		        the Spring Gemfire project, providing a thin wrapper over its
		        components.
		    
For further details please see Chapter 15, GemFire Support.
Spring Integration 2.1 adds several Channel Adapters for receiving and sending messages using the Advanced Message Queuing Protocol (AMQP). Furthermore, Spring Integration also provides a point-to-point Message Channel, as well as a publish/subscribe Message Channel that are backed by AMQP Exchanges and Queues.
For further details please see Chapter 10, AMQP Support.
As of version 2.1 Spring Integration provides support for MongoDB by providing a MongoDB-based MessageStore.
For further details please see Chapter 21, MongoDb Support.
As of version 2.1 Spring Integration supports Redis, an advanced key-value store, by providing a Redis-based MessageStore as well as Publish-Subscribe Messaging adapters.
For further details please see Chapter 22, Redis Support.
As of version 2.1, we've introduced a new Resource Inbound Channel Adapter that builds upon Spring's Resource abstraction to support greater flexibility across a variety of actual types of underlying resources, such as a file, a URL, or a class path resource. Therefore, it's similar to but more generic than the File Inbound Channel Adapter.
For further details please see Section 23.2, “Resource Inbound Channel Adapter”.
		       With Spring Integration 2.1, the JDBC Module also provides
		       Stored Procedure support by adding several new components, including
		       inbound/outbound channel adapters and an Outbound Gateway. The Stored
		       Procedure support leverages Spring's
		       SimpleJdbcCall
		       class and consequently supports stored procedures for:
		    
The Stored Procedure components also support Sql Functions for the following databases:
For further details please see Section 17.5, “Stored Procedures”.
		        Spring Integration 2.1 provides a new XPath-based Message Filter,
		        that is part of the XML module. The XPath Filter
		        allows you to filter messages using provided XPath Expressions.
		        Furthermore, documentation was added for the XML Validating Filter.
		    
For more details please see Section 31.8, “Using the XPath Filter” and Section 31.10, “XML Validating Filter”.
				Since Spring Integration 2.1, the Payload Enricher is provided. A
				Payload Enricher defines an endpoint that typically passes a
				Message
				to the exposed request channel and then expects a reply message.
				The reply message then becomes the root object for evaluation of
				expressions to enrich the target payload.
		    
For further details please see Section 6.2.3, “Payload Enricher”.
Spring Integration 2.1 provides two new Outbound Gateways in order to interact with remote File Transfer Protocol (FTP) or Secure File Transfer Protocol (SFT) servers. These two gateways allow you to directly execute a limited set of remote commands.
For instance, you can use these Outbound Gateways to list, retrieve and delete remote files and have the Spring Integration message flow continue with the remote server's response.
For further details please see Section 14.5, “FTP Outbound Gateway” and Section 25.7, “SFTP Outbound Gateway”.
As of version 2.1, we have exposed more flexibility with regards to session management for remote file adapters (e.g., FTP, SFTP etc).
                Specifically, the cache-sessions attribute, which is
                available via the XML namespace support, is now
                deprecated. Alternatively, we added the
                sessionCacheSize and sessionWaitTimeout
                attributes on the CachingSessionFactory.
            
For further details please see Section 14.6, “FTP Session Caching” and Section 25.3, “SFTP Session Caching”.
Router parameters have been standardized across all router implementations with Spring Integration 2.1 providing a more consistent user experience.
                With Spring Integration 2.1 the ignore-channel-name-resolution-failures
                attribute has been removed in favor of consolidating its behavior
                with the resolution-required attribute. Also,
                the resolution-required attribute now defaults to true.
            
                Starting with Spring Integration 2.1, routers will no longer silently
                drop any messages, if no default output channel was defined. This means,
                that by default routers now require at least one resolved channel (if no
                default-output-channel was set) and
                by default will throw a MessageDeliveryException
                if no channel was determined (or an attempt to send was not successful).
            
                If, however, you do desire to drop messages silently, simply set
                default-output-channel="nullChannel".
| ![[Important]](images/important.png) | Important | 
|---|---|
| With the standardization of Router parameters and the consolidation of the parameters described above, there is the possibility of breaking older Spring Integration based applications. | 
For further details please see Section 5.1, “Routers”
Spring Integration 2.1 ships with an updated XML Schema (version 2.1), providing many improvements, e.g. the Router standardizations discussed above.
From now on, users must always declare the latest XML schema (currently version 2.1). Alternatively, they can use the version-less schema. Generally, the best option is to use version-less namespaces, as these will automatically use the latest available version of Spring Integration.
Declaring a version-less Spring Integration namespace:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:int="http://www.springframework.org/schema/integration" xsi:schemaLocation="http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> ... </beans>
Declaring a Spring Integration namespace using an explicit version:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:int="http://www.springframework.org/schema/integration" xsi:schemaLocation="http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration-2.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> ... </beans>
The old 1.0 and 2.0 schemas are still there, but if an Application Context still references one of those deprecated schemas, the validator will fail on initialization.
Since version 2.0, the Spring Integration project uses Git for version control. In order to increase community visibility even further, the project was moved from SpringSource hosted Git repositories to Github. The Spring Integration Git repository is located at: https://github.com/SpringSource/spring-integration/
For the project we also improved the process of providing code contributions and we ensure that every commit is peer-reviewed. In fact, core committers now follow the same process as contributors. For more details please see:
https://github.com/SpringSource/spring-integration/wiki/Contributor-Guidelines
In an effort to provide better source code visibility and consequently to monitor the quality of Spring Integration's source code, an instance of Sonar was setup and metrics are gathered nightly and made avaiblable at:
For the 2.1 release of Spring Integration we also expanded the Spring Integration Samples project and added many new samples, e.g. samples covering AMQP support, the new payload enricher, a sample illustrating techniques for testing Spring Integration flow fragments, as well as an example for executing Stored Procedures against Oracle. For details please visit:
For a detailed migration guide in regards to upgrading an existing application that uses Spring Integration older than version 2.0, please see:
http://www.springsource.org/node/2976
Spring Integration 2.0 is built on top of Spring 3.0.5 and makes many of its features available to our users.
You can now use SpEL expressions within the transformer, router, filter, splitter, aggregator, service-activator, header-enricher, and many more elements of the Spring Integration core namespace as well as various adapters. There are many samples provided throughout this manual.
You can now benefit from Conversion Service support provided with Spring while configuring many Spring Integration components such as Datatype Channel. See Section 3.1.2, “Message Channel Implementations” as well Section 7.3.1, “Introduction”. Also, the SpEL support mentioned in the previous point also relies upon the ConversionService. Therefore, you can register Converters once, and take advantage of them anywhere you are using SpEL expressions.
Spring 3.0 defines two new strategies related to scheduling: TaskScheduler and Trigger Spring Integration (which uses a lot of scheduling) now builds upon these. In fact, Spring Integration 1.0 had originally defined some of the components (e.g. CronTrigger) that have now been migrated into Spring 3.0's core API. Now, you can benefit from reusing the same components within the entire Application Context (not just Spring Integration configuration). Configuration of Spring Integration Pollers has been greatly simplified as well by providing attributes for directly configuring rates, delays, cron expressions, and trigger references. See Section 3.3, “Channel Adapter” for sample configurations.
Our outbound HTTP adapters now delegate to Spring's RestTemplate for executing the HTTP request and handling its response. This also means that you can reuse any custom HttpMessageConverter implementations. See Section 16.3, “Http Outbound Gateway” for more details.
Also in 2.0 we have added support for even more of the patterns described in Hohpe and Woolf's Enterprise Integration Patterns book.
We now provide support for the Message History pattern allowing you to keep track of all traversed components, including the name of each channel and endpoint as well as the timestamp of that traversal. See Section 8.2, “Message History” for more details.
We now provide support for the Message Store pattern. The Message Store provides a strategy for persisting messages on behalf of any process whose scope extends beyond a single transaction, such as the Aggregator and Resequencer. Many sections of this document provide samples on how to use a Message Store as it affects several areas of Spring Integration. See Section 8.3, “Message Store”, Section 6.3, “Claim Check”, Section 3.1, “Message Channels”, Section 5.4, “Aggregator”, Chapter 17, JDBC Support, and Section 5.5, “Resequencer” for more details
We have added an implementation of the Claim Check pattern. The idea behind the Claim Check pattern is that you can exchange a Message payload for a "claim ticket" and vice-versa. This allows you to reduce bandwidth and/or avoid potential security issues when sending Messages across channels. See Section 6.3, “Claim Check” for more details.
We have provided implementations of the Control Bus pattern which allows you to use messaging to manage and monitor endpoints and channels. The implementations include both a SpEL-based approach and one that executes Groovy scripts. See Section 8.5, “Control Bus” and Section 7.6.2, “Control Bus” for more details.
We have added several new Channel Adapters and Messaging Gateways in Spring Integration 2.0.
We have added Channel Adapters for receiving and sending messages over the TCP and UDP internet protocols. See Chapter 28, TCP and UDP Support for more details. Also, you can checkout the following blog: TCP/UDP support
Twitter adapters provides support for sending and receiving Twitter Status updates as well as Direct Messages. You can also perform Twitter Searches with an inbound Channel Adapter. See Chapter 29, Twitter Adapter for more details.
The new XMPP adapters support both Chat Messages and Presence events. See Chapter 32, XMPP Support for more details.
Inbound and outbound File transfer support over FTP/FTPS is now available. See Chapter 14, FTP/FTPS Adapters for more details.
Inbound and outbound File transfer support over SFTP is now available. See Chapter 25, SFTP Adapters for more details.
We have also added Channel Adapters for receiving news feeds (ATOM/RSS). See Chapter 12, Feed Adapter for more details.
With Spring Integration 2.0 we've added Groovy support allowing you to use Groovy scripting language to provide integration and/or business logic. See Section 7.6, “Groovy support” for more details.
These symmetrical transformers convert payload objects to and from a Map. See Section 6.1, “Transformer” for more details.
These symmetrical transformers convert payload objects to and from JSON. See Section 6.1, “Transformer” for more details.
These symmetrical transformers convert payload objects to and from byte arrays. They also support the Serializer and Deserializer strategy interfaces that have been added as of Spring 3.0.5. See Section 6.1, “Transformer” for more details.
The core API went through some significant refactoring to make it simpler and more usable. Although we anticipate that the impact to the end user should be minimal, please read through this document to find what was changed. Especially, visit Section 5.1.5, “Dynamic Routers” , Section 7.2, “Messaging Gateways”, Section 16.3, “Http Outbound Gateway”, Section 4.1, “Message”, and Section 5.4, “Aggregator” for more details. If you are depending directly on some of the core components (Message, MessageHeaders, MessageChannel, MessageBuilder, etc.), you will notice that you need to update any import statements. We restructured some packaging to provide the flexibility we needed for extending the domain model while avoiding any cyclical dependencies (it is a policy of the framework to avoid such "tangles").
With Spring Integration 2.0 we have switched our build environment to use Git for source control. To access our repository simply follow this URL: http://git.springsource.org/spring-integration. We have also switched our build system to Gradle.
With Spring Integration 2.0 we have decoupled the samples from our main release distribution. Please read this blog to get more info New Spring Integration Samples We have also created many new samples, including samples for every new Adapter.
There is an amazing new visual editor for Spring Integration included within the latest version of SpringSource Tool Suite. If you are not already using STS, please download it here:
http://www.springsource.com/landing/best-development-tool-enterprise-java