I would suggest to pass the JSON data in the body as a POST
request.But if you still want to pass this as a parameter in URL,you will have to encode your URL like below just for example:-
for ex json is :->{"name":"ABC","id":"1"}
testurl:80/service?data=%7B%22name%22%3A%22ABC%22%2C%22id%22%3A%221%22%7D
for more information on URL encoding refer below