spring-integration/src/reference/docbook/changes-2.2-3.0.xml

<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="migration-2.2-3.0"
	xmlns:xi="http://www.w3.org/2001/XInclude"
	xmlns:xlink="http://www.w3.org/1999/xlink">
	<title>Changes Between 2.2 and 3.0</title>
	<section id="3.0-new-components">
		<title>New Components</title>
		<section id="3.0-request-mapping">
			<title>HTTP Request Mapping</title>
			<para>
				The HTTP module now provides powerful Request Mapping support for Inbound Endpoints. Class <classname>UriPathHandlerMapping</classname>
				was replaced by <classname>IntegrationRequestMappingHandlerMapping</classname>, which is registered under the bean name
				<code>integrationRequestMappingHandlerMapping</code> in the application context. Upon parsing of the HTTP Inbound Endpoint,
				a new <classname>IntegrationRequestMappingHandlerMapping</classname> bean is either registered or an existing bean is being reused.
				To achieve flexible Request Mapping configuration, Spring Integration provides the <code>&lt;request-mapping/&gt;</code>
				sub-element for the <code>&lt;http:inbound-channel-adapter/&gt;</code> and the <code>&lt;http:inbound-gateway/&gt;</code>.
				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 <xref linkend="http-namespace"/>.
			</para>
		</section>
		<section id="3.0-spel-customization">
			<title>Spring Expression Language (SpEL) Configuration</title>
			<para>
				A new <classname>IntegrationEvaluationContextFactoryBean</classname> is provided to allow
				configuration of custom <interfacename>PropertyAccessor</interfacename>s and functions for
				use in SpEL expressions throughout the framework. For more information see <xref linkend="spel" />.
			</para>
		</section>
		<section id="3.0-spel-functions">
			<title>SpEL Functions Support</title>
			<para>
				To customize the SpEL <interfacename>EvaluationContext</interfacename> with static
				<classname>Method</classname> functions, the new <code>&lt;spel-function/&gt;</code>
				component is introduced. Two built-in functions are also provided (<code>#jsonPath</code>
				and <code>#xpath</code>). For more information see <xref linkend="spel-functions" />.
			</para>
		</section>
		<section id="3.0-spel-property-accessors">
			<title>SpEL PropertyAccessors Support</title>
			<para>
				To customize the SpEL <interfacename>EvaluationContext</interfacename> with
				<interfacename>PropertyAccessor</interfacename> implementations
				the new <code>&lt;spel-property-accessors/&gt;</code> component is introduced.
				For more information see <xref linkend="spel-property-accessors" />.
			</para>
		</section>
		<section id="3.0-redis-new-components">
			<title>Redis: New Components</title>
			<para>
				A new Redis-based
				<interfacename><ulink url="http://docs.spring.io/spring-integration/docs/latest-ga/api/org/springframework/integration/store/MetadataStore.html">MetadataStore</ulink></interfacename>
				implementation has been added. The <classname>RedisMetadataStore</classname> can
				be used to maintain state of a <interfacename>MetadataStore</interfacename>
				across application restarts. This new <interfacename>MetadataStore</interfacename>
				implementation can be used with adapters such as:
			</para>
			<itemizedlist>
				<listitem>Twitter Inbound Adapters</listitem>
				<listitem>Feed Inbound Channel Adapter</listitem>
			</itemizedlist>
			<para>
				New queue-based components have been added. The <code>&lt;int-redis:queue-inbound-channel-adapter/&gt;</code>
				and the	<code>&lt;int-redis:queue-outbound-channel-adapter/&gt;</code> components are provided
				to perform 'right pop' and 'left push' operations on a Redis List, respectively.
			</para>
			<para>
				For more information see <xref linkend="redis" />.
			</para>
		</section>
		<section id="3.0-hcr">
			<title>Header Channel Registry</title>
			<para>
				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 <code>replyChannel</code> or <code>errorChannel</code> might be lost; for example
				when serializing
				a message. See <xref linkend="header-enricher"/> for more information.
			</para>
		</section>
		<section id="3.0-configurable-mongo-MS">
			<title>MongoDB support: New ConfigurableMongoDbMessageStore</title>
			<para>
				In addition to the existing <classname>eMongoDbMessageStore</classname>, a new
				<classname>ConfigurableMongoDbMessageStore</classname> has been introduced.
				This provides a more robust and flexible implementation of <interfacename>MessageStore</interfacename>
				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 <xref linkend="mongodb"/> for more information.
			</para>
		</section>
		<section id="3.0-syslog">
			<title>Syslog Support</title>
			<para>
				Building on the 2.2 <classname>SyslogToMapTransformer</classname> Spring
				Integration 3.0 now introduces
				<code>UDP</code> and <code>TCP</code> inbound channel adapters especially tailored
				for receiving SYSLOG messages. For more information, see
				<xref linkend="syslog"/>.
			</para>
		</section>
		<section id="3.0-tail">
			<title>'Tail' Support</title>
			<para>
				File 'tail'ing inbound channel adapters are now provided to generate messages when
				lines are added to the end of text files; see <xref linkend="file-tailing"/>.
			</para>
		</section>
		<section id="3.0-jmx">
			<title>JMX Support</title>
			<para>
				<itemizedlist>
					<listitem>
						A new <code>&lt;int-jmx:tree-polling-channel-adapter/&gt;</code> 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.
					</listitem>
					<listitem>
						The <classname>IntegrationMBeanExporter</classname> now allows the configuration of
						a custom <classname>ObjectNamingStrategy</classname> using the <code>naming-strategy</code>
						attribute.
					</listitem>
				</itemizedlist>
			</para>
			<para>
				For more information, see <xref linkend="jmx"/>.
			</para>
		</section>
		<section id="3.0-tcp-events">
			<title>TCP/IP Connection Events and Connection Management</title>
			<para>
				<classname>TcpConnection</classname>s now emit
				<interfacename>ApplicationEvent</interfacename>s (specifically
				<classname>TcpConnectionEvent</classname>s) when connections are
				opened, closed, or an exception occurs. This allows applications
				to be informed of changes to TCP connections using the normal
				Spring <interfacename>ApplicationListener</interfacename>
				mechanism.
			</para>
			<para>
				<classname>AbstractTcpConnection</classname> has been renamed
				<classname>TcpConnectionSupport</classname>; custom connections that
				are subclasses of this class, can use its methods to publish events.
				Similarly, <classname>AbstractTcpConnectionInterceptor</classname> has
				been renamed to <classname>TcpConnectionInterceptorSupport</classname>.
			</para>
			<para>
				In addition, a new <code>&lt;int-ip:tcp-connection-event-inbound-channel-adapter/&gt;</code>
				is provided; by default, this adapter sends all <classname>TcpConnectionEvent</classname>s
				to a <interfacename>Channel</interfacename>.
			</para>
			<para>
				Further, the TCP Connection Factories, now provide a new method
				<code>getOpenConnectionIds()</code>, which returns a list of identifiers for all
				open connections; this allows applications, for example, to broadcast to all
				open connections.
			</para>
			<para>
				Finally, the connection factories also provide a new method
				<code>closeConnection(String connectionId)</code> which allows applications
				to explicitly close a connection using its ID.
			</para>
			<para>
				For more information see <xref linkend="tcp-events"/>.
			</para>
		</section>
		<section id="3.0-inbound-script">
			<title>Inbound Channel Adapter Script Support</title>
			<para>
				The <code>&lt;int:inbound-channel-adapter/&gt;</code> now supports <code>&lt;expression/&gt;</code>
				and <code>&lt;script/&gt;</code> sub-elements to create a
				<interfacename>MessageSource</interfacename>; see <xref linkend="channel-adapter-expressions-and-scripts"/>.
			</para>
		</section>
		<section id="3.0-content-enricher-headers">
			<title>Content Enricher: Headers Enrichment Support</title>
			<para>
				The Content Enricher now provides configuration for <code>&lt;header/&gt;</code>
				sub-elements, to enrich the outbound Message with headers based on the reply Message from the underlying
				message flow. For more information see <xref linkend="payload-enricher"/>.
			</para>
		</section>
	</section>

	<section id="3.0-general">
		<title>General Changes</title>
		<section id="3.0-message-id">
			<title>Message ID Generation</title>
			<para>
				Previously, message ids were generated using the JDK <code>UUID.randomUUID()</code> 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 <xref linkend="message-id-generation"/>.
			</para>
		</section>
		<section id="3.0-gateway">
			<title>&lt;gateway&gt; Changes</title>
			<para>
				<itemizedlist>
					<listitem>
						It is now possible to set common headers across all gateway methods, and more options
						are provided for adding, to the message, information about which method was invoked.
					</listitem>
					<listitem>
						It is now possible to entirely customize the way that gateway method calls are mapped
						to messages.
					</listitem>
					<listitem>
						The <classname>GatewayMethodMetadata</classname> is now public class and it makes possible flexibly
						to configure the <classname>GatewayProxyFactoryBean</classname> programmatically from Java code.
					</listitem>
				</itemizedlist>
			</para>
			<para>
				For more information see <xref linkend="gateway"/>.
			</para>
		</section>
		<section id="3.0-http-endpointss">
			<title>HTTP Endpoint Changes</title>
			<para>
				<itemizedlist>
					<listitem>
						<emphasis role="bold">Outbound Endpoint 'encode-uri'</emphasis> - <code>&lt;http:outbound-gateway/&gt;</code>
						and <code>&lt;http:outbound-channel-adapter/&gt;</code> now
						provide an <code>encode-uri</code> attribute to allow disabling the encoding of the URI object
						before sending the request.
					</listitem>
					<listitem>
						<emphasis role="bold">Inbound Endpoint 'merge-with-default-converters'</emphasis> -
						<code>&lt;http:inbound-gateway/&gt;</code> and <code>&lt;http:inbound-channel-adapter/&gt;</code> now
						have a <code>merge-with-default-converters</code> attribute to include the list of default
						<interfacename>HttpMessageConverter</interfacename>s after the custom message converters.
					</listitem>
					<listitem>
						<emphasis role="bold">'If-(Un)Modified-Since' HTTP Headers</emphasis> - previously,
						'If-Modified-Since' and 'If-Unmodified-Since' HTTP headers were incorrectly processed
						within from/to HTTP headers mapping in the <classname>DefaultHttpHeaderMapper</classname>.
						Now, in addition correcting that issue, <classname>DefaultHttpHeaderMapper</classname> provides
						date parsing from formatted strings for any HTTP headers that accept date-time values.
					</listitem>
					<listitem>
						<emphasis role="bold">Inbound Endpoint Expression Variables</emphasis> -
						In addition to the existing <emphasis>#requestParams</emphasis> and <emphasis>#pathVariables</emphasis>,
						the <code>&lt;http:inbound-gateway/&gt;</code> and <code>&lt;http:inbound-channel-adapter/&gt;</code>
						now support additional useful variables: <emphasis>#matrixVariables</emphasis>, <emphasis>#requestAttributes</emphasis>,
						<emphasis>#requestHeaders</emphasis> and <emphasis>#cookies</emphasis>. These variables are available in
						both payload and header expressions.
					</listitem>
					<listitem>
						<emphasis role="bold">Outbound Endpoint 'uri-variables-expression'</emphasis> - HTTP Outbound Endpoints
						now support the <code>uri-variables-expression</code> attribute to specify
						an <interfacename>Expression</interfacename> to evaluate a <interfacename>Map</interfacename>
						for all URI variable placeholders within URL template. This allows selection of a different
						map of expressions based on the outgoing message.
					</listitem>
				</itemizedlist>
			</para>
			<para>
				For more information see <xref linkend="http"/>.
			</para>
		</section>
		<section id="3.0-json-transformers">
			<title>Jackson Support (JSON)</title>
			<para>
				<itemizedlist>
					<listitem>
						A new abstraction for JSON conversion has been introduced. Implementations for Jackson 1.x
						and Jackson 2 are currently provided, with the version being determined by presence on
						the classpath. Previously, only Jackson 1.x was supported.
					</listitem>
					<listitem>
						The <classname>ObjectToJsonTransformer</classname> and <classname>JsonToObjectTransformer</classname>
						now emit/consume headers containing type information.
					</listitem>
				</itemizedlist>
			</para>
			<para>
				For more information, see 'JSON Transformers' in <xref linkend="transformer"/>.
			</para>
		</section>
		<section id="3.0-id-for-chain-sub-components">
			<title>Chain Elements 'id' Attribute</title>
			<para>
				Previously, the <emphasis>id</emphasis> attribute for elements within a <code>&lt;chain&gt;</code> was
				ignored and, in some cases, disallowed. Now, the <emphasis>id</emphasis> attribute is allowed
				for all elements within a <code>&lt;chain&gt;</code>. The bean names of chain elements is a combination
				of the surrounding chain's <emphasis>id</emphasis> and the <emphasis>id</emphasis> of the element
				itself. For example: 'fooChain$child.fooTransformer.handler'.
				For more information see <xref linkend="chain"/>.
			</para>
		</section>
		<section id="3.0-corr-endpoint-empty-groups">
			<title>Aggregator 'empty-group-min-timeout' property</title>
			<para>
				The <classname>AbstractCorrelatingMessageHandler</classname> provides a new property
				<code>empty-group-min-timeout</code>
				to allow empty group expiry to run on a longer schedule than expiring partial groups. Empty groups will
				not be removed from the <interfacename>MessageStore</interfacename> until they have not been modified
				for at least this number of milliseconds. For more information see <xref linkend="aggregator-config"/>.
			</para>
		</section>
		<section id="3.0-filelistfilter">
			<title>Persistent File List Filters (file, (S)FTP)</title>
			<para>
				New <classname>FileListFilter</classname>s that use a persistent <classname>MetadataStore</classname> are
				now available. These can be used to prevent duplicate files after a system restart. See
				<xref linkend="file-reading"/>, <xref linkend="ftp-inbound"/>, and <xref linkend="sftp-inbound"/> for more information.
			</para>
		</section>
		<section id="3.0-scripting-variables">
			<title>Scripting Support: Variables Changes</title>
			<para>
				A new <code>variables</code> attribute has been introduced for scripting components.
				In addition, variable bindings are now allowed for inline scripts.
				See <xref linkend="groovy"/> and <xref linkend="scripting"/> for more information.
			</para>
		</section>
		<section id="3.0-direct-channel-lb-ref">
			<title>Direct Channel Load Balancing configuration</title>
			<para>
				Previously, when configuring <classname>LoadBalancingStrategy</classname> 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 <classname>LoadBalancingStrategy</classname>. You can now use <code>load-balancer-ref</code> to provide
				a reference to a custom implementation of the <classname>LoadBalancingStrategy</classname>.
				For more information see <xref linkend="channel-implementations-directchannel"/>.
			</para>
		</section>
		<section id="3.0-pub-sub">
			<title>PublishSubscribeChannel Behavior</title>
			<para>
				Previously, sending to a &lt;publish-subscribe-channel/&gt; that had
				no subscribers would return a <code>false</code> result. If used in conjunction with
				a <classname>MessagingTemplate</classname>, this would result in an exception being thrown.
				Now, the <classname>PublishSubscribeChannel</classname> has a property
				<code>minSubscribers</code> (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.
			</para>
		</section>
		<section id="3.0-(s)ftp-changes">
			<title>FTP, SFTP and FTPS Changes</title>
			<para>
				<emphasis role="bold">The FTP, SFTP and FTPS endpoints no longer cache sessions by default</emphasis>
			</para>
			<para>
				The deprecated <code>cached-sessions</code> 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 <classname>CachingConnectionFactory</classname> was introduced in
				release 2.1 and it became the preferred (and is now the only) way to cache sessions.
			</para>
			<para>
				The <classname>CachingConnectionFactory</classname> now provides a new method
				<code>resetCache()</code>. This immediately closes idle sessions and causes in-use
				sessions to be closed as and when they are returned to the cache.
			</para>
			<para>
				The <classname>DefaultSftpSessionFactory</classname> (in conjunction with a
				<classname>CachingSessionFactory</classname>) now supports multiplexing channels over
				a single SSH connection (SFTP Only).
			</para>
			<para>
				<emphasis role="bold">FTP, SFTP and FTPS Inbound Adapters</emphasis>
			</para>
			<para>
				Previously, there was no way to override the default filter used to process files retrieved
				from a remote server. The <code>filter</code> attribute determines which files are retrieved
				but the <classname>FileReadingMessageSource</classname> uses an
				<classname>AcceptOnceFileListFilter</classname>. 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.
			</para>
			<para>
				With this release, a new attribute <code>local-filter</code> allows you to override the
				default filter, for example with an <classname>AcceptAllFileListFilter</classname>, or some
				other custom filter.
			</para>
			<para>
				For users that wish the behavior of the <classname>AcceptOnceFileListFilter</classname>
				to be maintained across JVM executions, a custom filter that retains state, perhaps on
				the file system, can now be configured.
			</para>
			<para>
				Inbound Channel Adapters now support the <code>preserve-timestamp</code> attribute, which
				sets the local file modified timestamp to the timestamp from the server (default false).
			</para>
			<para>
				<emphasis role="bold">FTP, SFTP and FTPS Gateways</emphasis>
			</para>
			<para>
				<itemizedlist>
					<listitem>
						The gateways now support the <emphasis role="bold">mv</emphasis> command, enabling
						the renaming of remote files.
					</listitem>
					<listitem>
						The gateways now support recursive <emphasis role="bold">ls</emphasis> and
						<emphasis role="bold">mget</emphasis> commands, enabling
						the retrieval of a remote file tree.
					</listitem>
					<listitem>
						The gateways now support <emphasis role="bold">put</emphasis> and
						<emphasis role="bold">mput</emphasis> commands, enabling
						sending file(s) to the remote server.
					</listitem>
					<listitem>
						The <code>local-filename-generator-expression</code> attribute is now supported,
						enabling the naming of local files during retrieval. By default, the same
						name as the remote file is used.
					</listitem>
					<listitem>
						The <code>local-directory-expression</code> attribute is now supported,
						enabling the naming of local directories during retrieval based on the remote directory.
					</listitem>
				</itemizedlist>
			</para>
			<para>
				<emphasis role="bold">Remote File Template</emphasis>
			</para>
			<para>
				A new higher-level abstraction (<classname>RemoteFileTemplate</classname>) is provided over the
				<interfacename>Session</interfacename> 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 <code>*Template</code> implementations, reliably closes the underlying session while allowing
				low level access to the session when needed.
			</para>
			<para>
				For more information, see
				<xref linkend="ftp"/> and <xref linkend="sftp"/>.
			</para>
		</section>
		<section id="3.0-outbound-gateway-requires-reply">
			<title>'requires-reply' Attribute for Outbound Gateways</title>
			<para>
				All Outbound Gateways (e.g. <code>&lt;jdbc:outbound-gateway/&gt;</code> or <code>&lt;jms:outbound-gateway/&gt;</code>)
				are designed for 'request-reply' scenarios. A response is expected from the external service and
				will be published to the <code>reply-channel</code>, or the <code>replyChannel</code> message header.
				However, there are some cases where the external system might not always return a
				result, e.g. a <code>&lt;jdbc:outbound-gateway/&gt;</code>, when a SELECT ends with an empty <interfacename>ResultSet</interfacename>
				or, say, a Web Service is One-Way. An option is therefore needed to configure whether or not a
				<emphasis>reply</emphasis> is required.
				For this purpose, the <emphasis>requires-reply</emphasis> attribute has been introduced for Outbound Gateway components.
				In most cases, the default value for <emphasis>requires-reply</emphasis> is <code>true</code> and, if there is not any result,
				a <classname>ReplyRequiredException</classname> will be thrown. Changing the value to <code>false</code>
				means that, if an external service doesn't return anything, the message-flow will end at that point,
				similar to an Outbound Channel Adapter.
			</para>
			<note>
				The WebService outbound gateway has an additional attribute <code>ignore-empty-responses</code>; 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 <emphasis>requires-reply</emphasis> attribute.
				<emphasis>requires-reply</emphasis> is false by default for the WebService outbound gateway.
			</note>
			<para>
				Note, the <code>requiresReply</code> property was previously present in the <classname>AbstractReplyProducingMessageHandler</classname>
				but set to <code>false</code>, and there wasn't any way to configure it on Outbound Gateways using the XML namespace.
			</para>
			<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 <code>requires-reply</code> to false.
			</important>
		</section>
		<section id="3.0-amqp-mapping">
			<title>AMQP Outbound Gateway Header Mapping</title>
			<para>
				Previously, the &lt;int-amqp:outbound-gateway/&gt; mapped headers before invoking the message
				converter, and the converter could overwrite headers such as <code>content-type</code>. The
				outbound adapter maps the headers after the conversion, which means headers like
				<code>content-type</code> from the outbound <code>Message</code> (if present) are used.
			</para>
			<para>
				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 <classname>SimpleMessageConverter</classname>
				are <code>content-type</code> and <code>content-encoding</code>. Custom message converters
				may set other headers.
			</para>
		</section>
		<section id="3.0-stored-proc-sql-return-type">
			<title>Stored Procedure Components Improvements</title>
			<para>
				For more complex database-specific types, not supported by the standard
				<code>CallableStatement.getObject</code> method, 2 new additional
				attributes were introduced to the <code>&lt;sql-parameter-definition/&gt;</code>
				element with OUT-direction:
			</para>
			<itemizedlist>
				<listitem><emphasis>type-name</emphasis></listitem>
				<listitem><emphasis>return-type</emphasis></listitem>
			</itemizedlist>
			<para>
				<para>
					The <code>row-mapper</code> attribute of the Stored Procedure Inbound Channel Adapter
					<code>&lt;returning-resultset/&gt;</code> sub-element
					now supports a reference to a <interfacename>RowMapper</interfacename> bean
					definition. Previously, it contained just a class name (which is still supported).
				</para>
				<para>
					For more information see <xref linkend="stored-procedures"/>.
				</para>
			</para>
		</section>
		<section id="3.0-ws-outbound-uri-substitution">
			<title>Web Service Outbound URI Configuration</title>
			<para>
				Web Service Outbound Gateway 'uri' attribute now supports <code>&lt;uri-variable/&gt;</code> substitution for all
				URI-schemes supported by Spring Web Services. For more information see <xref linkend="outbound-uri"/>.
			</para>
		</section>
		<section id="3.0-redis">
			<title>Redis Adapter Changes</title>
			<para>
				<itemizedlist>
					<listitem>
						The Redis Inbound Channel Adapter can now use a <code>null</code> value for <code>serializer</code>
						property, with the raw data being the message payload.
					</listitem>
					<listitem>
						The Redis Outbound Channel Adapter now has the <code>topic-expression</code> property to determine
						the Redis topic against the Message at runtime.
					</listitem>
					<listitem>
						The Redis Inbound Channel Adapter, in addition to the existing <code>topics</code> attribute,
						now has the <code>topic-patterns</code> attribute.
					</listitem>
				</itemizedlist>
			</para>
			<para>
				For more information, see <xref linkend="redis"/>.
			</para>
		</section>
		<section id="3.0-advising-filters">
			<title>Advising Filters</title>
			<para>
				Previously, when a &lt;filter/&gt; had a &lt;request-handler-advice-chain/&gt;, the discard
				action was all performed within the scope of the advice chain (including any downstream flow
				on the <code>discard-channel</code>). The filter element now has an attribute
				<code>discard-within-advice</code> (default <code>true</code>), to allow the discard action to
				be performed after the advice chain completes. See <xref linkend="advising-filters"/>.
			</para>
		</section>
		<section id="3.0-annotation-advice">
			<title>Advising Endpoints using Annotations</title>
			<para>
				Request Handler Advice Chains can now be configured using annotations. See
				<xref linkend="advising-with-annotations"/>.
			</para>
		</section>
		<section id="3.0-o-t-s-t">
			<title>ObjectToStringTransformer Improvements</title>
			<para>
				This transformer now correctly transforms <code>byte[]</code> and <code>char[]</code>
				payloads to <classname>String</classname>. For more information see <xref linkend="transformer"/>.
			</para>
		</section>
		<section id="3.0-jpa-changes">
			<title>JPA Support Changes</title>
			<para>
				Payloads to <emphasis>persist</emphasis> or
				<emphasis>merge</emphasis> can now be of type
				<interfacename><ulink url="http://docs.oracle.com/javase/7/docs/api/java/lang/Iterable.html"
						>java.lang.Iterable</ulink></interfacename>.
			</para>
			<para>
				In that case, each object returned by the
				<interfacename>Iterable</interfacename> is treated as
				an entity and persisted or merged using the underlying
				<interfacename>EntityManager</interfacename>.
				<emphasis>NULL</emphasis> values returned by the iterator are ignored.
			</para>
			<para>
				The JPA adapters now have additional attributes to optionally 'flush' and 'clear'
				entities from the associated persistence context after performing persistence operations.
			</para>
			<para>
				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 <code>first-result</code> and <code>first-result-expression</code> attributes
				to the gateway definition. <xref linkend="jpa-retrieving-outbound-gateway"/>.
			</para>
			<para>
				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
				<code>max-results</code> attribute has been introduced to replace
				<code>max-number-of-results</code>, which has been deprecated.
				<code>max-results</code> and <code>max-results-expression</code>
				are used to provide the maximum number of results,
				or an expression to compute the maximum number of results, respectively, in the
				result set.
			</para>
			<para>For more information see <xref linkend="jpa"/>.</para>
		</section>
		<section id="3.0-dalay-expression">
			<title>Delayer: delay expression</title>
			<para>
				Previously, the <code>&lt;delayer&gt;</code> provided a <code>delay-header-name</code> attribute
				to determine the <emphasis>delay</emphasis> value at runtime. In complex cases it was necessary
				to precede the <code>&lt;delayer&gt;</code> with a <code>&lt;header-enricher&gt;</code>.
				Spring Integration 3.0 introduced the <code>expression</code> attribute and <code>expression</code>
				sub-element for dynamic delay determination. The <code>delay-header-name</code> attribute is now deprecated
				because the header evaluation can be specified in the <code>expression</code>. In addition,
				the <code>ignore-expression-failures</code> was introduced to control the behavior when an
				expression evaluation fails.
				For more information see <xref linkend="delayer"/>.
			</para>
		</section>
		<section id="3.0-jdbc-mysql-v5_6_4">
			<title>JDBC Message Store Improvements</title>
			<para>
				<emphasis>Spring Integration 3.0</emphasis> adds a new set of DDL
				scripts for <emphasis>MySQL</emphasis> version 5.6.4 and higher.
				Now <emphasis>MySQL</emphasis> supports <emphasis>fractional
				seconds</emphasis> and is thus improving the FIFO ordering when
				polling from a MySQL-based Message Store. For more information,
				please see <xref linkend="jdbc-message-store-generic"/>.
			</para>
		</section>
		<section id="3.0-event-for-imap-idle">
			<title>IMAP Idle Connection Exceptions</title>
			<para>
				Previously, if an IMAP idle connection failed, it was logged but there was no mechanism to
				inform an application. Such exceptions now generate <classname>ApplicationEvent</classname>s.
				Applications can obtain these events using an <code>&lt;int-event:inbound-channel-adapter&gt;</code>
				or any <interfacename>ApplicationListener</interfacename> configured to receive an
				<classname>ImapIdleExceptionEvent</classname> or one of its super classes.
			</para>
		</section>
		<section id="3.0-tcp-headers">
			<title>Message Headers and TCP</title>
			<para>
				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
				<classname>TcpMessageMapper</classname>
				enables the selection of the headers, and an appropriate (de)serializer needs to be
				configured to write the resulting <interfacename>Map</interfacename> to the
				TCP stream. A <classname>MapJsonSerializer</classname> is provided as a convenient
				mechanism to transfer headers and payload over TCP.
				For more information see <xref linkend="ip-headers"/>.
			</para>
		</section>
		<section id="3.0-jms-mdca-te">
			<title>JMS Message Driven Channel Adapter</title>
			<para>
				Previously, when configuring a <code>&lt;message-driven-channel-adapter/&gt;</code>, if you wished to
				use a specific <interfacename>TaskExecutor</interfacename>, it was necessary to declare a container
				bean and provide it to the adapter using the <code>container</code> attribute. The
				<code>task-executor</code> 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.
			</para>
		</section>
		<section id="3.0-rmi-ec">
			<title>RMI Inbound Gateway</title>
			<para>
				The RMI Inbound Gateway now supports an <code>error-channel</code> attribute. See
				<xref linkend="rmi-inbound"/>.
			</para>
		</section>
		<section id="3.0-xslt-transformer">
			<title>XsltPayloadTransformer</title>
			<para>
				You can now specify the transformer factory class name using the
				<code>transformer-factory-class</code> attribute. See <xref linkend="xml-xslt-payload-transformers"/>
			</para>
		</section>
	</section>
</section>