Securing web services using Talend's Open Studio for ESB - part VI

This is the sixth article in a series on securing web services using Talend's Open Studio for ESB. Up to now we have seen how to create and secure a SOAP service, client job and route in the Studio, and how to deploy them to the Talend runtime container. For the remaining articles in this series, we will switch our focus to REST web services instead. In this article we will look at how to implement a REST service and client in the Studio.

1) Implement a "double-it" REST Service in the Studio

First let's look at how we can create implement the "double-it" service as a REST service instead. Open the Studio and right click on "Job Designs" and select "Create job". Create a new job called "DoubleItRESTService". Drag the 'tRESTRequest', 'tXMLMap' and 'tRESTResponse' components from the palette into the central window. Connect them by right-clicking on 'tRESTRequest' and selecting "Row / New Output" and drag the link to 'tXMLMap', calling the output 'Request'. Right-click on 'tXMLMap' and select "Row / New Output" and drag the link to 'tRESTResponse', calling the output 'Response':

Now let's design the REST endpoint by clicking on 'tRESTRequest'. Our simple "double-it" service will accept a path parameter corresponding to the number to double. It will return an XML or JSON response containing the doubled number wrapped in a "result" tag. Edit the 'REST endpoint' to add "/doubleit" at the end of the URL. In the REST API mapping, edit the "URI Pattern" to be "/{number}". Now click on the "Output Flow" for "Request" and click on the three dots that appear. Click the "+" button and change the column name to "number" and the Type to "Integer":

Click "OK" and then double-click on 'tXMLMap'. Left-click on the "Number" column on the left-hand side, and drag it over to the right-hand side to the "body" column. Select "Add Linker to Target Node". Now click on "Request.number" on the right-hand side and then on the three dots. Change the expression to "2 * Request.number" to implement the "doubling" logic. Finally, rename the "root" element to "result":

Finally click "OK", save the job and run it. We can test via a console that the job is working OK using a tool such as curl:

• curl -H "Accept: application/xml" http://localhost:8088/doubleit/15
• Response: <?xml version="1.0" encoding="UTF-8"?><result>30</result>
• Response if we ask for JSON: {"result":30}

2) Implement a "double-it" REST client in the Studio

Now we'll design a client job for the "double-it" REST service in the Studio. Right-click on "Job Designs" and create a new job called "DoubleItRESTClient". Drag a 'tFixedFlowInput', 'tRESTClient' and two 'tLogRow' components from the palette into the central window. Link the components, sending the 'tRESTClient'
"Response" to one 'tLogRow' component and the "Error" to the other:

Now click on 'tFixedFlowInput' and then 'Edit Schema'. Add a new column called "number" of type "Integer", and click "yes" to propagate the changes. In the inline table, add a value for the number. Finally, click on 'tRESTClient' and specify "http://localhost:8088/doubleit/" for the URL, and row1.number for the relative path. Keep the default HTTP Method of "GET" and "XML" for the "Accept Type":

Now save the job and run it. The service response should be displayed in the window of the run tab. In the next article, we'll look at how to secure this REST service in the Studio when deploying it to the Talend runtime container.