VFS Transport

The Virtual File System (VFS) transport is used for handling files. It is based on the Apache Commons VFS implementation, so you must include the commons-vfs.jar file in the Carbon classpath to enable the VFS transport. The transport is a module of the Apache Synapse project, and the synapse-vfs-transport.jar file contains the necessary classes, including those that implement the listener and sender APIs:

org.apache.synapse.transport.vfs.VFSTransportListener
org.apache.synapse.transport.vfs.VFSTransportSender

To enable the VFS transport, edit the <ESB_HOME>/repository/conf/axis2/axis2.xml file and uncomment the VFS listener and the VFS sender as follows:

<transportreceiver name="vfs" class="org.apache.synapse.transport.vfs.VFSTransportListener"/>
...
<transportSender name="vfs" class="org.apache.synapse.transport.vfs.VFSTransportSender"/>

To track failures in file processing, which can occur when a resource becomes unavailable, the VFS transport creates and maintains a failed records file. This text file contains a list of files that failed to be processed. When a failure occurs, an entry with the failed file name and the timestamp is logged in the text file. When the next polling iteration occurs, the VFS transport checks each file against the failed records file, and if a file is listed as a failed record, it will skip processing and schedule a move task to move that file.

To configure a VFS endpoint, use the vfs:file prefix in the URI. For example:

<endpoint>
   <address uri="vfs:file:///home/user/test/out"/>
</endpoint>

The VFS transport also supports the FTPS protocol. The configuration is identical to other protocols with the only difference being the URL prefixes.

VFS Service Level Parameters

The VFS transport does not have any global parameters to be configured. Rather, it has a set of service-level parameters that must be specified for each service.

Parameter Name	Description	Required	Possible Values	Default Value
transport.vfs. FileURI	The URI where the files you want to process are located.	Yes	A valid file URI in the following form: `file://<path>`
transport.vfs. ContentType	Content type of the files processed by the transport.	Yes	A valid content type for the files (e.g., `text/xml`)
transport.vfs. FileNamePattern	If the VFS listener should process only a subset of the files available at the specified file URI location, use this parameter to select those files by name using a regular expression.	No	A regular expression to select files by name (e.g., `*\.xml`)
transport. PollInterval	The polling interval for the transport receiver to poll the file URI location. The value is expressed in seconds unless you add "ms" for milliseconds, e.g., "2" or "2000ms" to specify 2 seconds.	No	A positive integer
transport.vfs. ActionAfterProcess	Whether to move or delete the files after the transport has processed them.	No	`MOVE` or `DELETE`	`DELETE`
transport.vfs. ActionAfterFailure	Whether to move or delete the files if a failure occurs.	No	`MOVE` or `DELETE`	`DELETE`
transport.vfs. MoveAfterProcess	Where to move the files after processing if ActionAfterProcess is MOVE.	Yes, if ActionAfterProcess is MOVE	A valid file URI
transport.vfs. MoveAfterFailure	Where to move the files after processing if ActionAfterFailure is MOVE.	Yes, if ActionAfterFailure is MOVE	A valid file URI
transport.vfs. ReplyFileURI	The location where reply files should be written by the transport.	No	A valid file URI
transport.vfs. ReplyFileName	The name for reply files written by the transport.	No	A valid file name	`response.xml`
transport.vfs. MoveTimestampFormat	The pattern/format of the timestamps added to file names as prefixes when moving files.	No	A valid timestamp pattern (e.g., `yyyy-MM-dd'T'HH:mm:ss.SSSZ`)
transport.vfs. Streaming	Whether files should be transferred in streaming mode	No	`true` or `false`	`false`
transport.vfs. ReconnectTimeout	Reconnect timeout value in seconds to be used in case of an error when transferring files	No	A positive integer	30 sec
transport.vfs. MaxRetryCount	Maximum number of retry attempts to carry out in case of errors.	No	A positive integer	3
transport.vfs.Append	When writing the response to a file, whether the response should be appended to the response file instead of overwriting the file. This value should be defined as a query parameter in the out/reply file URI. For example: `"vfs:file:///home/user/test/out?` `transport.vfs.Append=true"` or: `<parameter name="` `transport.vfs.ReplyFileURI">` `file:///home/user/test/out?` `transport.vfs.Append=true` `</parameter>`	No	`true` or `false`	`false` (the response file will be completely overwritten).
transport.vfs. MoveAfterFailedMove	Where to move the failed file.	No	A valid file URI
transport.vfs. FailedRecordsFileName	The name of the file that maintains the list of failed files.	No	A valid file name	`vfs-move-failed-records.` `properties`
transport.vfs. FailedRecordsFile Destination	Where to store the failed records file.	No	A folder URI	`repository/conf/`
transport.vfs. MoveFailedRecord TimestampFormat	Entries in the failed records file include the name of the file that failed and the timestamp of its failure. This property configures the time stamp format.	No	A valid timestamp pattern (e.g., `yyyy-MM-dd'T'HH:mm:ss.SSSZ`)	`dd-MM-yyyy HH:mm:ss`
transport.vfs. FailedRecordNext RetryDuration	The time in milliseconds to wait before retrying the move task.	No	A positive integer	3000 milliseconds
transport.vfs.Locking	By default, file locking is enabled in the VFS transport. This parameter lets you configure the locking behavior on a per service basis. You can also disable locking globally by specifying the parameter at the receiver level and selectively enable locking only for a set of services.	No	`enable` or `disable`	`enable`

For more information, see: