Write Email Attachment to a File

To be able to do this, you must be able to first retrieve the attachment from the Receive variable as described in the previous post. Also this post assumes that you have some basic knowledge of BPEL, Adapters and XSLT functions. Just for understanding, by default, Attachment is stored in the ATTACHMENT table in SOA_INFRA user schema and the table's row reference (called href) is received in the Receive variable. When ora:getAttachmentContent() function is called, it fetches the attachment content from the table in base64 encoded format and assigns to the target custom variable.

There are 2 ways you can write incoming attachment to an external file.

ora:writeBinaryToFile()

There's inbuilt function ora:writeBinaryToFile() that automatically extracts the attachment from the Attachment href (in the binary format) and writes to the specified target file (hence you don’t need to use ora:getAttachmentContent() in front of it). Follow the below steps to write it to file using ora:writeBinaryToFile() .

• If you're starting from the beginning, then create a new Simple BPEL project with Define service later option
• Drag and Drop the UMS Adapter and configure the adapter. It will automatically create the schema for UMS Adapter and WSDL file.
• Go to BPEL process and drag and drop Receive Activity on the swim lane. Connect the activity to UMS Adapter and create a Receive variable ( Receive1_ReceiveNotification_InputVariable )
• Create another variable of the type attachment and name $CustomAttachmentVariable
• Next drag and drop the Assign Activity and drop Expression on the $CustomAttachmentVariable on the Target side
• Assign the following in the Source side. In BPEL source , comple Assign statement would look like as shown below. -
• Receive1_ReceiveNotification_InputVariable','body','/ns2:message/ns2:attachment[1] - is the BPEL 1.1. notation of the variable as mentioned earlier. Even in BPEL 2.0 you must use the same format.
• /u01/app/oracle/userdir/NewAttachment.xml - specifies the full path of the file where attachment content needs to be written
• $CustomAttachmentVariable/ns2:attachment - is just meant to complete the Assign Statement. It doesn’t have any significance in writing the file. Run the project, it should work.

Using the File/FTP Adapter

The other way is to use a File Adapter through a opaque schema variable. Follow the below steps to write a file with the content retrieved from attachment. Note - You don’t have any control over the content of the file, so whatever comes in the attachment will be written directly. If you want to parse the content of the file before write read my another post - Parse and Read contents of Email Attachment in the BPEL process.

• Drag and Drop a File adapter to the above project (created with UMS Adapter) and choose option Native Format Translation is not Required (Schema is Opaque).
• Go to BPEL, drag and drop an Invoke activity, connect to File Adapter just created and create an Invoke Variable (Invoke1_Write_InputVariable.opaque )
• Assign the Attachment content to the variable just created as shown below. Note - we are using ora:getAttachmentContent() to first fetch the content in opaque base64 format which is then assigned to the opaque variable of the File Adapter.
• Run the project, it will write the attachment content in a file with the name specified in the File Adapter. You can also retrieve the name of the attachment and write with the same name if required. Read post - How to retrieve name of the Email Attachment .

Let me know if any issues and I'll try to help!

Changing the Archive File Name in Inbound File/FTP Adapter

Requirement:

To customize the archive file name, remove the junk characters from the archived file name. The default format is as under.

SOA 10g - filename_yyyymmdd_hh24mmss
SOA 11g - filename_encryptedToken_yyyymmdd_hh24mmss (new format introduced with 11g)

The possible customization is given in the solution below.

Solution:

SOA 10g: 

You have a JCA property for FIle/FTP adapter, UseLongArchiveFileName, which can be used to prefix the process name to the archive filename to make the format filename_processname_timestamp.

SOA 11g (11.1.1.3/+) 

UseLongArchiveFileName is not available in 11g. Apply Patch 10155914 and it will become available.    

SOA 11g (11.1.1.5/+) 

Apply Patch 13249896.
A new property  UseDigest can be used now in addition to  UseLongArchiveFileName (11g format as filename_processname_digest_timestamp) with File/FTP adapter.
By default UseDigest is set to true which leads to the digest (encrypted token) being sandwiched in the filename and timestamp as filename_digest_timestamp.
Setting this property to false will change the format to filename_timetamp. To use this property edit the .jca file to include this property as given below.

SOA 11g (11.1.1.7/+)

UseDigest property will be available by default without the need to apply the above patch.

There is, however, no further customization possible (presently) in terms of adding instance id to the file name or specifying custom file name. Hope the same gets available in the 11.1.1.7(+) or 12C version.

Polling files on-demand : File Based Triggers

Many a times there is a need to trigger the polling of File/FTP Adapter on the basis of some event e.g. after process A has finished writing the file F1, process B should poll for the file F1 OR just process the files only between 10.00 AM to 11.00 AM. While the above could be accomplished to some extent using Sync Read operation, but it requires the knowledge of the File Name in advance (wild cards can't be used).

Well, the solution is File-Based Triggers. File-based triggers can be used to control the File/FTP adapter activation. File Triggers are nothing but the files with .trg extension. The content of trigger file doesn't matter. When File-based triggers are used, File/FTP adapter checks for the existence of a Trigger file (e.g. ReadFile.trg) before reading the actual file. If the trigger file is found, it reads and processes the actual file else it does nothing. You can configure how frequently the adapter checks for the trigger file and hence can control the processing of the actual files.
To use a File-Based trigger, follow the below steps.
1.) Define a File/FTP adapter with Read Operation.
2.) On the File Polling page, Check the option Use trigger file and provide the Trigger File details as shown below.

3.) Complete the adapter wizard.
4.) Follow the normal steps to create a bpel process to poll the file. Deploy this process.

As soon as the process is deployed, File/FTP adapter looks for the trigger file in the C:/TriggerFileDir location. If it finds the triger file, it will poll and process the file. How frequently it looks for the trigger file depends on the property TriggerFileStrategy (we didn't specify this property anywhere because the property is set already by default to value EndpointActivation).

The various possible values for TriggerFileStrategy are:
OnceOnly: The adapter will looks for the trigger file only once in its lifetime. Once it finds the trigger file, it remembers that across restarts and redeployments. This could be very risky as the adapter would never look for a trigger file again in future.

EveryTime: The adapter looks for the trigger file everytime it goes for polling the file. At every polling interval, it checks if the trigger file is there or not. If the trigger file is present, it picks the actual file else it will do nothing and will check for the existence of trigger file at next polling cycle.

EndpointActivation (Default): The adapter looks for the trigger file every time the composite is activated that means everytime you Restart/Activate/Redeploy your composite.

Add the property in .jca file of your File Adapter as shown below and it's done.

Note: You may want to delete the Trigger file after your file has been successfully processed. For this, there is no Delete operation. But you can use Sync Read operation to read the trigger file and check Delete Files after successful retrieval option.

Happy to hear back if any suggestions or comments!