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This language is an extension to the Simple language so the Simple syntax applies also. So the table below only lists the additional.
As opposed By contrast to the Simple language, the File Language also supports the use of Constant expressions so you can to enter a fixed filename, for example.

All the file tokens use the same expression name as the method on the java.io.File object, for instance . For example: file:absolute refers to the java.io.File.getAbsolute() method. Notice that

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File token example

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File Token Example

Relative Paths

We have a java.io.File handle for the file hello.txt in the following relative directory: .\filelanguage\test. And we configure our endpoint to use this starting directory .\filelanguage.

The file tokens will return asreturned are:

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Absolute Paths

We have a java.io.File handle for the file hello.txt in the following absolute directory: \workspace\camel\camel-core\target\filelanguage\test. And we configure out endpoint to use the absolute starting directory: \workspace\camel\camel-core\target\filelanguage.

The file tokens will return asare:

Samples

Examples

You can enter a fixed Constant expression such as myfile.txt:

fileName="myfile.txt"

Lets assume we use the file consumer to read files and want to move the read files to backup folder with the current date as a sub folder. This can be archieved achieved using an expression like:

fileName="backup/${date:now:yyyyMMdd}/${file:name.noext}.bak"

relative folder names are also supported so suppose the backup folder should be a sibling folder then you can append append .. as:

fileName="../backup/${date:now:yyyyMMdd}/${file:name.noext}.bak"

As this is an extension to the Simple language we have access to all the goodies from this language also, so in this use case we want to use the the in.header.type as a parameter in the dynamic expression:

fileName="../backup/${date:now:yyyyMMdd}/type-${in.header.type}/backup-of-${file:name.noext}.bak"

If you have a custom custom Date you want to use in the expression then Camel supports retrieving dates from the message header.

fileName="orders/order-${in.header.customerId}-${date:in.header.orderDate:yyyyMMdd}.xml"

And finally we can also use a bean expression to invoke a POJO class that generates some some String output (or convertible to String) to be used:

fileName="uniquefile-${bean:myguidgenerator.generateid}.txt"

And of course all this can be combined in one expression where you can use the File Language, Simple and the Bean language in one combined expression. This is pretty powerful for those common file path patterns.

Using Spring's PropertyPlaceholderConfigurer

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with the File

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Component

In Camel you can use the File Language directly from the Simple language which makes a Content Based Router easier to do in Spring XML, where we can route based on file extensions as shown below:

  <from uri="file://input/orders"/>
     <choice>
       <when>
           <simple>${file:ext} == 'txt'</simple>
           <to uri="bean:orderService?method=handleTextFiles"/>
       </when>
       <when>
           <simple>${file:ext} == 'xml'</simple>
           <to uri="bean:orderService?method=handleXmlFiles"/>
       </when>
       <otherwise>
           <to uri="bean:orderService?method=handleOtherFiles"/>
       </otherwise>
    </choice>

If you use the fileName option on the File endpoint to set a dynamic filename using the File Language then make sure you
use the alternative syntax (available from Camel 2.5 onwards) to avoid clashing with Springs Spring's PropertyPlaceholderConfigurer.

<bean id="propertyPlaceholder" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location" value="classpath:bundle-context.cfg" />
</bean>

<bean id="sampleRoute" class="SampleRoute">
    <property name="fromEndpoint" value="${fromEndpoint}" />
    <property name="toEndpoint" value="${toEndpoint}" />
</bean>

fromEndpoint=activemq:queue:test
toEndpoint=file://fileRoute/out?fileName=test-$simple{date:now:yyyyMMdd}.txt

Notice how we use the the $simple{} syntax in the toEndpoint above.
If you don't do this, there is a they will clash and Spring will throw an exception like:

org.springframework.beans.factory.BeanDefinitionStoreException:
Invalid bean definition with name 'sampleRoute' defined in class path resource [bundle-context.xml]:
Could not resolve placeholder 'date:now:yyyyMMdd'

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The File language is part of camel-core.