You can create custom sling sevlets using Maven and deploy the servlet to Adobe CQ. Once deployed, you can use AJAX to post data to the sling servlet. For example:
//Use JQuery AJAX request to post data to a Sling Servlet
$.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 } });
For details, see http://scottsdigitalcommunity.blogspot.ca/2013/06/posting-form-data-to-adobe-cq-using.html.