Mule4 using read connector to read a file

Question

I am very new to Mule4 and using it for the first time. I am trying to move a file from one directory to another. I have a "Read file" connector and "Write file" connector. In the Read connector, I specified the file path and the working directory. on the Write connector, I also specified the working directory and the path. However, the file is not moved from the source to target directory. But if I add an HTTP listener at the beginning of the flow, then it will work if I access it through http://localhost:8081. But I want to know how can I accomplish this whenever there is a new file in the source, so the flow automatically moves the file from source to target directory? Please see the screenshot

Answer 1

You need something to trigger the flow to run. file:read doesn’t do this automatically that’s why http requests to trigger works for you.

All flows need a ‘Source’ to trigger them unless you are calling them from other flows using flow-ref (or from dataweave using a lookup()).

If you know the exact file you want then you can put a scheduler before your file:read to trigger the flow:

<scheduler>
  <scheduling-strategy>
    <fixed-frequency startDelay="5" frequency="10" timeUnit="SECONDS"/>
  </scheduling-strategy>
</scheduler>

Or you can use a file:listener to listen for new files in a directory etc as the source directly:

<flow name="onNewFile">
  <file:listener config-ref="file" directory="test-data/in" autoDelete="true">
    <scheduling-strategy>
      <fixed-frequency frequency="1000"/>
    </scheduling-strategy>
  </file:listener>
  ...
</flow>

You can use fixed frequency or cron. More details here: https://docs.mulesoft.com/mule-runtime/4.1/scheduler-xml-reference