Call web service from javascript

Question

I could call web service from block with code below : $jsonObject=json_decode(file_get_contents("http://www.testservice.com:50001/Services/Magento.asmx/getPayer?input=".$datasJson));

How can i call service from java script? I tried with code below, but it's all not work.

urlBuilder.createUrl('http://wsq.starcosmosgroup.com:50001/Services/Magento.asmx/getPayer?input=', {}),
JSON.stringify({
     parameter1: 'data1',
     parameter2: 'data2'
}

UPDATE :

I tried to get the data from service for change the billing address data in checkout page. I adding the code below, and add 'jquery' to the define, but it made the other function error, so how can i get the data from the service?

billing-address.js :

getBill: function (prefix) {
   payload = {
        parameter1: prefix,
        parameter2: 'data'
   };
   url = "http://www.testservice.com:50001/Services/Magento.asmx/getPayer?input="+JSON.stringify(payload);

   alert(url);
   $.get(url, function(response) {
        data = response;
        alert(response);
   });
   return data;
},

Answer 1

I suggest for you two ways:

1) Magento Ajax > Magento controller > Call the external server

In this case, we need to build the Magento controller. We can use a buit-in class Magento\Framework\HTTP\Client\Curl to work with HTTP protocol.

2) Magento Ajax > Call the external server directly.

We will have an issue with CORS (Cross-Origin Resource Sharing). So, in this case, make sure the external server allows accessing from your Magento server.

---

We simply use $.ajax, $.get, $.post for Ajax call.