将JS Post Ajax转换为AngularJS Post Factory

var xhr = new XMLHttpRequest();
xhr.open("POST", "http://example.com/api", true);
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    var response = JSON.parse(xhr.responseText);
    console.log(response);
  }
};
var data = {
  name: "John",
  age: 30
};
xhr.send(JSON.stringify(data));

angular.module("myApp", [])
  .controller("myController", function($scope, $http) {
    $scope.sendPostRequest = function() {
      var data = {
        name: "John",
        age: 30
      };
      $http.post("http://example.com/api", data)
        .then(function(response) {
          console.log(response.data);
        })
        .catch(function(error) {
          console.log(error);
        });
    };
  });