var settings = {
  "async": true,
  "crossDomain": true,
  "url": "http://dlj.bz/api/urlshortener",
  "method": "POST",
  "headers": {
    "content-type": "application/json"
  },
  "processData": false,
  "data": "{\"long_url\": \"http://www.sina.com.cn\"}"
}

$.ajax(settings).done(function (response) {
  console.log(response);
});