Saturday, March 1, 2014

How to get a JSON response with WSO2 Data Services Server (wso2dss) ?

Latest version of DSS can be downloaded from here. (At the moment it's wso2dss-3.1.1).

Data Services Server support for both XML and JSON outputs. In order to get a JSON output, you need to change following configurations.

Add following parameter to 'axis2.xml' and in 'axis2_client.xml'. (In axis2_client.xml this parameter is already there, but its default value is set to false. These two files are located in '{DSS_HOME}/repository/conf/axis2/' directory).

'<parameter name="httpContentNegotiation">true</parameter>'

Note that if you are using tenant, then the above parameter need to be set in 'tenant-axis2.xml' as well.

Restart the server. We are done.

We need to use content-negotiation when doing the requests. i.e We need to pass 'Accept' header with the request. Example request done for customersInBoston operation in the RDBMSSample is given bellow. (This sample 'RDBMSSample' service is deployed in server by default).

curl -v -H "Accept:application/json" http://localhost:9783/services/samples/RDBMSSample/customersInBoston

{"customers":{"customer":[{"customer-name":"","contact-last-name":"Yoshido","contact-first-name":"Juri","phone":"6175559555","city":"Boston","country":"USA"},{"customer-name":"Diecast Collectables","contact-last-name":"Franco","contact-first-name":"Valarie","phone":"6175552555","city":"Boston","country":"USA"}]}}


  1. Hi Dinusha:
    Thanks for nice blog and is very helpful. I have question. How to return custom response code and message in DSS when the select query or stored procedure returns null data.
    SELECT custname, custadd from cust_table where custnum = : custnum

    Now this select query assume returns null(no data found for the customer number supplied )
    In that case, I want to return a JSON with error
    "Error" :

    "error_code" : 25,
    "error_msg" : "No customer found for :customer Number"
    "error_status" : "ERROR"

    Let me know if there is way to achieve with DSS.


    1. Hi Venkat,

      Can you please share the information, if you found the solution for your scenario.


  2. How do I modify the data in sample database using the above rest method ??

    I tried this but no result

  3. Working with GET only not with POST

  4. This was helpful. Thanks for the post :)

  5. Thanks for the online support all ..

  6. This comment has been removed by the author.

  7. i have the rest data service. But when i send to endpoint with accept header property to application/json with all the config you have mentioned I am getting this error

    {"Fault":{"Code":"","Reason":"Error while writing to the output stream using JsonWriter","Detail":""}}

    The rest service works fine for xml