Handle HTTP GET request and execute Java logic

[marco.testa]

Hi,

I'm not sure I've correctly understood your scenario. basically what I've understood is that you have a data adapter which connects to web servers and app servers to check connectivity and publish the results. But instead of letting the adapter perform these checks on a regular basis, you want to trigger these checks manually from outside your adapter with a http request, served by the Lightstreamer Server. Am I correct?
In this case you may use the 'send message'. Basically your client sends a message to the Lightstreamer Server, and the server forwards this request to the MetadataAdapter on the 'notifyUserMessage' method. The Metadata Adapter then has to call your Data Adapter and forward the request to it, in order to trigger the checks.
How to perform the 'send message' depends on the Client API you are using, but, if you are using a Presto or Vivace Edition, you may use directly a HTTP request as explained in section 4.4 'Sending Messages' of the Generic Client Network Protocol Tutorial.
Keep in mind that you have to create a new session before sending a send_message request, since the sessionId is one of the requested parameters, so you cannot just send a single HTTP request but you have to follow the Lightstreamer network protocol as described in the document.
According to HTTP specifications, requests to Lightstreamer Server should always be issued through the POST method, since as a general rule they cause side effects on the Server behaviour, but, for testing purposes, it may be easier to use the GET method and it will work as well (for more detail see section 2.1.2 'GET method vs. POST method' of the same document).


I hope I've correctly addressed your question.
Marco