How to use Custom sling servlets in AEM applications

Question: How can I use Custom create sling servlets in AEM Applications?

Answer: You can create custom sling servlets using Maven and deploy the servlet to Adobe CQ. Once deployed, you can use AJAX to post data to the sling servlet. 

For example:

$.ajax({

 type: 'POST',

 url: '/bin/mySearchServlet',

 data: 'id=' + claimId + '&firstName=' + myFirst + '&lastName=' + myLast + '&address=' + address + '&cat=' + cat + '&state=' + state + '&details=' + details + '&date=' + date + '&city=' + city,

 success: function(msg) {

  alert(msg); //display the data returned by the servlet

 }

});

Adobe Complete Article: http://helpx.adobe.com/adobe-cq/using/custom-sling-servlets.html