[angularjs] Angular, content type is not being sent with $http

Angular is not adding the correct content type option, I tried the following command:

$http({
    url: "http://localhost:8080/example/teste",
    dataType: "json",
    method: "POST",
    headers: {
        "Content-Type": "application/json"
    }
}).success(function(response){
    $scope.response = response;
}).error(function(error){
    $scope.error = error;
});

The code above generates the following http request:

POST http://localhost:8080/example/teste HTTP/1.1
Host: localhost:8080
Connection: keep-alive
Content-Length: 0
Cache-Control: no-cache
Pragma: no-cache
Origin: http://localhost:8080
User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31
Content-Type: application/xml
Accept: application/json, text/plain, */*
X-Requested-With: XMLHttpRequest
Referer: http://localhost:8080/example/index
Accept-Encoding: gzip,deflate,sdch
Accept-Language: pt-BR,pt;q=0.8,en-US;q=0.6,en;q=0.4
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
Cookie: JSESSIONID=C404CE2DA653136971DD1A3C3EB3725B

As you can see, instead of "application/json", the content type is "application/xml". Am I missing something here ?

Just to show an example of how to dynamically add the "Content-type" header to every POST request. In may case I'm passing POST params as query string, that is done using the transformRequest. In this case its value is application/x-www-form-urlencoded.

// set Content-Type for POST requests
angular.module('myApp').run(basicAuth);
function basicAuth($http) {
    $http.defaults.headers.post = {'Content-Type': 'application/x-www-form-urlencoded'};
}

Then from the interceptor in the request method before return the config object

// if header['Content-type'] is a POST then add data
'request': function (config) {
  if (
    angular.isDefined(config.headers['Content-Type']) 
    && !angular.isDefined(config.data)
  ) {
    config.data = '';
  }
  return config;
}

Great! The solution given above worked for me. Had the same problem with a GET call.

 method: 'GET',
 data: '',
 headers: {
        "Content-Type": "application/json"
 }

In case it's useful to anyone. For AngularJS 1.5x I wanted to set CSRF for all requests and I found that when I did this:

$httpProvider.defaults.headers.get = { 'CSRF-Token': afToken }; 
$httpProvider.defaults.headers.put = { 'CSRF-Token': afToken };
$httpProvider.defaults.headers.post = { 'CSRF-Token': afToken }; 

Angular removed the content type so I had to add this:

$httpProvider.defaults.headers.common = { "Content-Type": "application/json"};

Otherwise I get a 415 media type error.

So I am doing this to configure my application for all requests:

angular.module("myapp.maintenance", [])
    .controller('maintenanceCtrl', MaintenanceCtrl)
    .directive('convertToNumber', ConvertToNumber)
    .config(configure);

MaintenanceCtrl.$inject = ["$scope", "$http", "$sce", "$window", "$document", "$timeout", "$filter", 'alertService'];
configure.$inject = ["$httpProvider"];

// configure the header tokens for  CSRF for http operations in this module
function configure($httpProvider) {

    const afToken = angular.element('input[id="__AntiForgeryToken"]').attr('value');

    $httpProvider.defaults.headers.get = { 'CSRF-Token': afToken }; // only added for GET
    $httpProvider.defaults.headers.put = { 'CSRF-Token': afToken }; // added for PUT
    $httpProvider.defaults.headers.post = { 'CSRF-Token': afToken }; // added for POST

    // for some reason if we do the above we have to set the default content type for all 
    // looks like angular clears it when we add our own headers
    $httpProvider.defaults.headers.common = { "Content-Type": "application/json" };

}

         $http({
                method: 'GET',
                url:'/http://localhost:8080/example/test' + toto,
                data: '',
                headers: {
                    'Content-Type': 'application/json'
                }
            }).then(
                function(response) {
                    return response.data;
                }, 
                function(errResponse) {
                    console.error('Error !!');
                    return $q.reject(errResponse);
                }

$http({
    url: 'http://localhost:8080/example/teste',
    dataType: 'json',
    method: 'POST',
    data: '',
    headers: {
        "Content-Type": "application/json"
    }

}).success(function(response){
    $scope.response = response;
}).error(function(error){
    $scope.error = error;
});

Try like this.