components/camel-tarfile/src/main/docs/tarFile-dataformat.adoc

= Tar File DataFormat
:doctitle: Tar File
:shortname: tarFile
:artifactid: camel-tarfile
:description: Archive files into tarballs or extract files from tarballs.
:since: 2.16
:supportlevel: Stable
:tabs-sync-option:
//Manually maintained attributes
:camel-spring-boot-name: tarfile

*Since Camel {since}*

The Tar File Data Format is a message compression
and decompression format. Messages can be marshalled (compressed) to
Tar Files containing a single entry, and Tar Files containing a single
entry can be unmarshalled (decompressed) to the original file contents.

There is also an aggregation strategy that can
aggregate multiple messages into a single Tar File.

== TarFile Options


// dataformat options: START
include::partial$dataformat-options.adoc[]
// dataformat options: END


== Marshal

In this example, we marshal a regular text/XML payload to a compressed
payload using Tar File compression, and send it to an ActiveMQ queue
called MY_QUEUE.

[source,java]
-----------------------------------------------------------------------
from("direct:start").marshal().tarFile().to("activemq:queue:MY_QUEUE");
-----------------------------------------------------------------------

The name of the Tar entry inside the created Tar File is based on the
incoming `CamelFileName` message header, which is the standard message
header used by the file component. Additionally, the
outgoing `CamelFileName` message header is automatically set to the
value of the incoming `CamelFileName` message header, with the ".tar"
suffix. So, for example, if the following route finds a file named
"test.txt" in the input directory, the output will be a Tar File named
"test.txt.tar" containing a single Tar entry named "test.txt":

[source,java]
-----------------------------------------------------------------------------------------------
from("file:input/directory?antInclude=*/.txt").marshal().tarFile().to("file:output/directory");
-----------------------------------------------------------------------------------------------

If there is no incoming `CamelFileName` message header (for example, if
the file component is not the consumer), then the
message ID is used by default, and since the message ID is normally a
unique generated ID, you will end up with filenames like
`ID-MACHINENAME-2443-1211718892437-1-0.tar`. If you want to override
this behavior, then you can set the value of the `CamelFileName` header
explicitly in your route:

[source,java]
---------------------------------------------------------------------------------------------------------------------------
from("direct:start").setHeader(Exchange.FILE_NAME, constant("report.txt")).marshal().tarFile().to("file:output/directory");
---------------------------------------------------------------------------------------------------------------------------

This route would result in a Tar File named "report.txt.tar" in the
output directory, containing a single Tar entry named "report.txt".

== Unmarshal

In this example we unmarshal a Tar File payload from an ActiveMQ queue
called MY_QUEUE to its original format, and forward it for processing to
the `UnTarpedMessageProcessor`.

[source,java]
-----------------------------------------------------------------------------------------------
from("activemq:queue:MY_QUEUE").unmarshal().tarFile().process(new UnTarpedMessageProcessor()); 
-----------------------------------------------------------------------------------------------

If the Tar File has more than one entry, the usingIterator option of
TarFileDataFormat to be true, and you can use splitter to do the further
work.

[source,java]
----------------------------------------------------------------------------------------------------
  TarFileDataFormat tarFile = new TarFileDataFormat();
  tarFile.setUsingIterator(true);
  from("file:src/test/resources/org/apache/camel/dataformat/tarfile/?delay=1000&noop=true")
    .unmarshal(tarFile)
    .split(bodyAs(Iterator.class))
        .streaming()
          .process(new UnTarpedMessageProcessor())
    .end();
----------------------------------------------------------------------------------------------------

Or you can use the TarSplitter as an expression for splitter directly
like this

[source,java]
----------------------------------------------------------------------------------------------------
   from("file:src/test/resources/org/apache/camel/dataformat/tarfile?delay=1000&noop=true")
     .split(new TarSplitter())
        .streaming()
        .process(new UnTarpedMessageProcessor())
     .end();
----------------------------------------------------------------------------------------------------

IMPORTANT: You cannot use TarSplitter in _parallel_ mode with the splitter.


== Aggregate

[NOTE]
====
Please note that this aggregation strategy requires eager completion
check to work properly.
====

In this example, we aggregate all text files found in the input directory
into a single Tar File that is stored in the output directory. 

[source,java]
-------------------------------------------------
   from("file:input/directory?antInclude=*/.txt")
     .aggregate(new TarAggregationStrategy())
       .constant(true)
       .completionFromBatchConsumer()
       .eagerCheckCompletion()
   .to("file:output/directory");
-------------------------------------------------

The outgoing `CamelFileName` message header is created using
java.io.File.createTempFile, with the ".tar" suffix. If you want to
override this behavior, then you can set the value of
the `CamelFileName` header explicitly in your route:

[source,java]
------------------------------------------------------------
   from("file:input/directory?antInclude=*/.txt")
     .aggregate(new TarAggregationStrategy())
       .constant(true)
       .completionFromBatchConsumer()
       .eagerCheckCompletion()
     .setHeader(Exchange.FILE_NAME, constant("reports.tar"))
   .to("file:output/directory");
------------------------------------------------------------

== Dependencies

To use Tar Files in your camel routes, you need to add a dependency on
*camel-tarfile*, which implements this data format.

If you use Maven you can add the following to your `pom.xml`,
substituting the version number for the latest & greatest release (see
the download page for the latest versions).

[source,xml]
----------------------------------------------------------
<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-tarfile</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>
----------------------------------------------------------


include::spring-boot:partial$starter.adoc[]