In this scenario, a pre-job and a post-job are added to the Job describes in Finding duplicate files between two folders to handle files before and after the execution of the main data Job.
For more technologies supported by Talend, see Talend components.
As described in the above-mentioned scenario, when the main data Job is started, it creates a temporary text file to store the fetched filenames. If the specified temporary file already exists, it will be overwritten.
To prevent possible loss of data, the pre-job saves a backup copy of the specified file by renaming it, if it exists, before the main Job is executed.
After the execution of the main data Job, the post-job deletes the temporary file created by the data Job and restores the backup file, if any.