INT-2892 Add 'local-filter' to (S)FTP Adapters

Allow the replacement of the default AcceptOnceFileListFilter.

src/reference/docbook/ftp.xml

@@ -151,6 +151,7 @@ protected void postProcessClientBeforeConnect(T client) throws IOException {
     remote-directory="some/remote/path"
     remote-file-separator="/"
     local-filename-generator-expression="#this.toUpperCase() + '.a'"
+    local-filter="myFilter"
     local-directory=".">
     <int:poller fixed-rate="1000"/>
 </int-ftp:inbound-channel-adapter>]]></programlisting>
@@ -174,13 +175,20 @@ protected void postProcessClientBeforeConnect(T client) throws IOException {
 	(e.g. <code>filename-regex=".*\.test$"</code>). And of course if you need complete control you can use <code>filter</code>
 	attribute and provide a reference to any custom implementation of the
 	<classname>org.springframework.integration.file.filters.FileListFilter</classname>, a strategy interface for filtering a
-	list of files.
+	list of files. This filter determines which remote files are retrieved.
   	</para>
-  	<note>
-	As of Spring Integration 2.0.2, we have added a 'remote-file-separator' attribute. That allows you to configure a
-	file separator character to use if the default '/' is not applicable for your particular environment.
+	<note>
+	Beginning with 3.0, you can also specify a filter used to filter the files locally, once they have
+	been retrieved. The default filter is an <classname>AcceptOnceFileListFilter</classname> which prevents processing
+	files with the same name multiple times in the same JVM execution; this can now be overridden
+	(for example with an <classname>AcceptAllFileListFilter</classname>), using the <code>local-filter</code> attribute.
+	Previously, the default	<classname>AcceptOnceFileListFilter</classname> could not be overridden.
 	</note>
-  	<para>
+	<para>
+	The 'remote-file-separator' attribute allows you to configure a
+	file separator character to use if the default '/' is not applicable for your particular environment.
+	</para>
+	<para>
   	Please refer to the schema for more details on these attributes.
   	</para>
   	<para>

src/reference/docbook/sftp.xml

@@ -227,6 +227,7 @@ xsi:schemaLocation="http://www.springframework.org/schema/integration/sftp
 			local-directory="file:target/foo"
 			auto-create-local-directory="true"
 			local-filename-generator-expression="#this.toUpperCase() + '.a'"
+			local-filter="myFilter"
 			delete-remote-files="false">
 		<int:poller fixed-rate="1000"/>
 </int-sftp:inbound-channel-adapter>]]></programlisting>
@@ -251,8 +252,15 @@ xsi:schemaLocation="http://www.springframework.org/schema/integration/sftp
 	(e.g. <code>filename-regex=".*\.test$"</code>). And of course if you need complete control you can use the <code>filter</code>
 	attribute to provide a reference to a custom implementation of the
 	<classname>org.springframework.integration.file.filters.FileListFilter</classname> - a strategy interface for filtering a
-	list of files.
+	list of files. This filter determines which remote files are retrieved.
   	</para>
+	<note>
+	Beginning with 3.0, you can also specify a filter used to filter the files locally, once they have
+	been retrieved. The default filter is an <classname>AcceptOnceFileListFilter</classname> which prevents processing
+	files with the same name multiple times in the same JVM execution; this can now be overridden
+	(for example with an <classname>AcceptAllFileListFilter</classname>), using the <code>local-filter</code> attribute.
+	Previously, the default	<classname>AcceptOnceFileListFilter</classname> could not be overridden.
+	</note>
   	<para>
   	Please refer to the schema for more detail on these attributes.
   	</para>

src/reference/docbook/whats-new.xml

@@ -88,6 +88,27 @@
 				URI-schemes supported by Spring Web Services. For more information see <xref linkend="outbound-uri"/>.
 			</para>
 		</section>
+		<section id="3.0-xFTP-ib">
+			<title>(S)FTP(S) Inbound Adapters</title>
+			<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>
+		</section>
 		<section id="3.0-xFTP-gw">
 			<title>(S)FTP(S) Gateways</title>
 			<para>