IBM BPM, V8.0.1, All platforms > Authoring services in Integration Designer > Services and service-related functions > Access external services with adapters > Configure and using adapters > IBM WebSphere Adapters > Flat Files > Overview of WebSphere Adapter for Flat Files > Technical overview > Inbound processing

File retrieval

During inbound processing, you can manage the retrieval of the files by using the Poll event files for modified content or the Time interval for polling unchanged files property.

You can also use the Include only the newly appended content property to retrieve only the appended file contents.

The Poll event files for modified content property and the Time interval for polling unchanged files property are mutually exclusive properties.


File retrieval based on last recorded time stamp

The Poll event files for modified content property enables the adapter to poll for event files repeatedly (when the file content is changed) in the event directory during the subsequent poll cycles after the previous event poll. The adapter then retrieves the event files and delivers them to the endpoint in the next poll cycle.

When you configure this property, the adapter retrieves the new files added to the event directory since the last poll cycle along with the existing modified files.

This property enables the adapter to monitor file changes based on the last modified time stamp of each file. When the adapter is started for the first time, all event files are polled and processed from the event directory. The adapter does not delete any polled event file from the event directory after event processing.

During the next poll cycles, only those event files are picked for polling whose lastModifiedTimeStamp values have changed. If the lastModifiedTimeStamp for a file is same, it means that the file is not changed and therefore it is not picked up for polling. This property allows for polling the complete content of the event file every time the file content is changed. See the Poll event files for modified content property details.

You can also configure the adapter to deliver the newly appended file contents at the end of the file by using the Include only the newly appended content property. This property is enabled when you select the Poll event files for modified content property in the external service wizard.

If there is a change in the last modified time stamp value, during the next poll cycle, the adapter checks the event file for any change in the file content. The changes to the file contents that are considered by the adapter for polling again are in the form of appended business objects. If the appended business objects exist, the adapter retrieves only the appended file contents by comparing the file with the file contents of the previous poll. The adapter compares by using the total number of business objects in the previously polled contents and the contents in the current poll. It does not process any business object if the counts of the business objects are same or less than the last poll.

The following scenarios illustrate how the adapter decides if a business object is to be delivered to the endpoint. In this example, three business objects are taken as a sample count. The scenarios depict how the adapter processes the business objects based upon their new processing order in the event file.

When the server is restarted after a shutdown, the adapter polls all the contents of the files modified during this time to the endpoint that also include the appended contents.

See the Include only the newly appended content property details.

If you select the Poll event files for modified content property, then you cannot configure the Time interval for polling unchanged files and File pass by reference properties.


File retrieval based on time interval

The Time interval for polling unchanged files property monitors the changes to files in the event directory for the specified time interval. When you configure this property, the adapter polls the files for event processing that do not undergo any change during the time interval.

The adapter also polls files that are currently being edited but are not saved during the specified time interval. The unsaved contents are not processed during the event processing. This configuration prevents occurrence of any erroneous results.

When the adapter polls the directory, it uses this property to check if a file is modified by any event during the specified time interval. The adapter uses the lastModifiedStamp values of the files to determine if a file is changed during the time interval.

The adapter retrieves the unchanged files in their present state and the changed files from their last saved state. See the Time interval for polling unchanged files property details.

If you select the Time interval for polling unchanged files property, then you cannot configure the Poll event files for modified content property.

Inbound processing


Related tasks:

Setting deployment and runtime properties


Related reference:

Activation specification properties