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h1. Preliminary notes

This use case can only be reproduced with Talend Integration Suite.
It is an alternative way to undertake what is done in the use cases "Data Flow - From a job to Petals using a tPetalsOutput" and "Data Flow - From a job to Petals using a tBufferOutput".
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h1. Rationale

Generate a data flow in a job, write it into a file and send this file as an attachment inside Petals.


The input message provides nothing.
The job's result and an attachment file are expected in the response.

h1. Creating and exporting the job

The job to be executed performs the following actions:
# The job generates a data flow.
# This data flow is written into a file, as an XML document (it could also be any kind of file, e.g. CSV, positional...).

h2. Creating the job

The job is made up of two components:
# The tRowGenerator generates the data flow.
# The tFileOutputXML serializes the data flow as an XML file. The file location is defined by a context variable (of type String).

Here is the overall aspect of the job.

!JobToPetals_file_job.jpg!

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Here is the schema and the generation settings for the tRowGenerator component.

!JobToPetals_buf_trgschema.jpg!

h2. Exporting the job

Select the job and right-click it. Select *Export to Petals ESB*.
Update the target destination.
Let the job be exposed as a singleton.

Click *Edit the exported contexts* to export the file location context.

You should have the following dialog:

!JobToPetals_file_export.jpg!

Click *Finish*.



h1. Deploying and testing in Petals


h2. Looking at the generated WSDL

In the created Petals service assembly, the most interesting thing to look at is the WSDL.
Indeed, the WSDL will determine the way the exported service will be called.

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The input message's description expects no parameter.

{code:lang=xml}
<xs:element name="executeJob" type="tns:executeJob" />
<xs:complexType name="executeJob">
<xs:sequence>
<xs:element minOccurs="0" name="contexts" type="tns:talendContexts" />
<xs:element minOccurs="0" name="in-attachments" type="tns:inAttachments" />
<xs:element maxOccurs="unbounded" minOccurs="0" name="in-data-bean" type="tns:inRow" />
<xs:element maxOccurs="unbounded" minOccurs="0" name="talend-option" type="xs:string" />
</xs:sequence>
</xs:complexType>

<xs:complexType name="talendContexts">
<xs:sequence>
</xs:sequence>
</xs:complexType>

<xs:complexType name="inAttachments">
<xs:sequence>
</xs:sequence>
</xs:complexType>

<xs:complexType name="inRow">
<xs:sequence>
</xs:sequence>
</xs:complexType>
{code}

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And the output message includes the job's result and the attached file.

{code:lang=xml}
<xs:element name="executeJobResponse" type="tns:executeJobResponse" />
<xs:complexType name="executeJobResponse">
<xs:sequence>
<xs:element minOccurs="0" name="talend-job-output" type="tns:talendJobOutput" />

<xs:element maxOccurs="unbounded" minOccurs="0" name="executionResult" nillable="true" type="ns1:stringArray" />
<xs:element minOccurs="0" name="outAttachment" type="tns:outAttachments" />
<xs:element maxOccurs="unbounded" minOccurs="0" name="outDataBean" nillable="true" type="tns:outRow" />

<xs:element name="outputLocation" nillable="true" type="tns:attachment" />

</xs:sequence>
</xs:complexType>
{code}

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As you can see, the WSDL generation has taken into account the exported context.


h2. Deploying and testing this new service

Since we use attachments, we will prefer using a Java client instead of SoapUI.
However, it is possible to use SoapUI to send or receive messages with attachments. Just make sure the MTOM property is activated.

The first thing to do is to create a service-unit for the Petals-BC-SOAP component, that exposes (consumes) our _Talend job as a service_ outside the bus.
This step is not described here. You can take a look at the Petals-BC-SOAP documentation and the Petals Studio documentation.
Just make sure the SOAP configuration uses the InOut MEP.

Then, to generate a client from the WSDL, you can use Apache CXF or Axis2.
In the scope of this use case, Apache CXF is used. Only the client class is shown here.

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The client's code is the following:

{code:lang=java}
TODO
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Notice that the MTOM-mode was activated. Not enabling it will result in errors.


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The execution output is:

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If the job execution fails, the 0 is replaced by another integer, e.g. 1.
One failure reason can be, as an example, that the database is not started.

To determine the act cause of a problem, you would have to use logging features available in the Talend palet.
However, let's make it clear, the job's logs are managed independently of Petals and its monitoring capabilities.