Configuring How Sender Endpoints Interact with the File System

Overview

Sender endpoints interact with the file system in basic ways. You can configure a number of the aspects of this behavior including:

if the endpoint creates the directory where it writes files
how the endpoint names temporary files

The default behavior of a sender endpoint that is to automatically create the target directory for its files if that directory does not already exist. To configure an endpoint to not create the target directory you set its autoCreateDirectory attribute to false. If the directory does not exist, the endpoint will do nothing. You will have to create the directory manually.

Example 3.2 shows the configuration for a sender endpoint that does not automatically create its target directory.

Example 3.2. Sender Endpoint that Does Create Its Target Directory

<beans xmlns:file="http://servicemix.apache.org/file/1.0"
	       xmlns:foo="http://servicemix.org/demo/">

  <file:sender service="foo:fileSender"
               endpoint="fileSender"
               directory="outbox"
               autoCreateDirectory="false" />
  ...
</beans>

Appending data

By default, sender endpoints overwrite existing files. If a message wants to reuse the name of an existing file, the file on the file system is overwritten. You can configure a sender endpoint to append the message to the existing file by setting the endpoint's append attribute to true.

Example 3.3 shows the configuration for an endpoint that appends messages to a file if it already exists.

Example 3.3. Sender Endpoint that Appends Existing Files

<beans xmlns:file="http://servicemix.apache.org/file/1.0"
	       xmlns:foo="http://servicemix.org/demo/">

  <file:sender service="foo:fileSender"
               endpoint="fileSender"
               directory="outbox"
               append="true" />
  ...
</beans>

Temporary file naming

By default, sender endpoints check the message exchange, or the message itself, for the name to use for the file being written. If the endpoint cannot determine a name for the target file, it will use a temporary file name. Table 3.2 describes the attributes used to generate the temporary file name.

	Note
	Checking for the name of the file to write is handled by the marshaler. For more information on marshalers see File Marshalers.

Table 3.2. Attributes Used to Determine a Temporary File Name

Name	Description	Default
`tempFilePrefix`	Specifies the prefix used when creating output files.	`servicemix-`
`tempFileSuffix`	Specifies the file extension to use when creating output files.	`.xml`

The generated file names will have the form tempFilePrefixXXXXXtempFileSuffix. The five Xs in the middle of the filename will be filled with randomly generated characters. So given the configuration shown in Example 3.4, a possible temporary filename would be widgets-xy60s.xml.

Example 3.4. Configuring a Sender Endpoint's Temporary File Prefix

<beans xmlns:file="http://servicemix.apache.org/file/1.0"
	       xmlns:foo="http://servicemix.org/demo/">

  <file:sender service="foo:fileSender"
               endpoint="fileSender"
               directory="outbox"
               tempFilePrefix="widgets-" />
  ...
</beans>