Android : How to call the JSON webservice?

I am trying to call this web service but it's response is null

<script type="text/javascript">
    jQuery(document).ready(function(){
        var user = {nick :"rajesh", password:"123456", device_id:"123456677"};
        jQuery.ajax({
            type: "post",
            data :JSON.stringify(user),
            url: "http://localhost:81/sazpin/user/users/index.json",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function(data) {
                console.log(data);
            }
        });
    });
</script>

My httppost client is

HttpClient httpClient = new DefaultHttpClient();

// post header
HttpPost httpPost = new HttpPost(url);                  
httpPost.setEntity(se);        
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type", "application/json");

Please somebody help me How to call this webservice and get the response?