Jonathan Lalou's blog

Case

You use a filter connector in Mule ESB 2.2.1, to perform any operation (let’s say: to send them on JMS, but this does not matter). You would like to filter files owing to their size, ie stop the handling of files larger than 10,000,000 bytes for instance.

We assume the files you handle are text files (not binary).

Solution

In your Mule XML config file, add the following block, using a short Groovy script:

<message-properties-transformer name="add-properties">
     <add-message-property key="fileSizeOK"
             value="#1" />
 </message-properties-transformer>

In the tag <file:inbound-endpoint>, add the attribute: transformer-refs="add-properties"
Now, add a tag <message-property-filter pattern="fileSizeOK=true"/>. Your outbound should then be similar to:

			<outbound>
                <filtering-router>
                    <jms:outbound-endpoint queue="lalou.jonathan.jms.queue"
						connector-ref="jmsConnector"/>
                    <message-property-filter pattern="fileSizeOK=true"/>
                </filtering-router>
                <forwarding-catch-all-strategy>
                    <file:outbound-endpoint path="/my/folder/"
                        connector-ref="fileConnector" outputPattern="error/#[header:originalFilename].too_big.#[function:dateStamp:yyyyMMdd_HHmmss_SSSSS].KO" />
                </forwarding-catch-all-strategy>
			</outbound>

Many thanks to Vincent N. for his help.