如何从这些站点正确获取简单数据而没有CORS错误

Question

I have a problem getting data from this two sites:

http://app.lotto.pl/wyniki/?type=dl

and

Eurolottery .

I know that the problem is associated with CORS and I managed to get data using Chrome CORS extension and that code:

var HttpClient = function() {
  this.get = function(aUrl, aCallback) {
      var anHttpRequest = new XMLHttpRequest();
      anHttpRequest.onreadystatechange = function() { 
          if (anHttpRequest.readyState == 4 && anHttpRequest.status == 200)
              aCallback(anHttpRequest.responseText);
      }

      anHttpRequest.open( "GET", aUrl, true );            
      anHttpRequest.send( null );
  }
}

var client = new HttpClient();
client.get('http://app.lotto.pl/wyniki/?type=dl', function(response) {
    var currentDraw = response;
    x = currentDraw.split("\n").slice(1, 7).sort().join(" ");
    console.log(x);
    }
);

And I tried to use CORS tutorial code with that:

function createCORSRequest(method, url) {
  var xhr = new XMLHttpRequest();
  if ("withCredentials" in xhr) {
    // XHR for Chrome/Firefox/Opera/Safari.
    xhr.open(method, url, true);
  } else if (typeof XDomainRequest != "undefined") {
    // XDomainRequest for IE.
    xhr = new XDomainRequest();
    xhr.open(method, url);
  } else {
    // CORS not supported.
    xhr = null;
  }
  return xhr;
}

// Helper method to parse the title tag from the response.
function getTitle(text) {
  return text.match('<title>(.*)?</title>');
}

// Make the actual CORS request.
function makeCorsRequest() {
  // This is a sample server that supports CORS.

  var url = 'http://api.bentasker.co.uk/lottopredict/?action=LatestResults&key=751fbf6ddfb7c3857d898c21bfdc2b22&game=3&draws=Any';
  var xhr = createCORSRequest('GET', url);
  if (!xhr) {
    alert('CORS not supported');
    return;
  }

  // Response handlers.
  xhr.onload = function() {
    var text = xhr.responseText;
    var title = getTitle(text);

    console.log(text.split("\n"));

  };

  xhr.onerror = function() {
    alert('Woops, there was an error making the request.');
  };

  xhr.send();
}

makeCorsRequest();

But in both situations it doesn't work properly. What is the easiest way to get data from sites posted above using javascript?

Answer 1

如果您不想设置自己的服务器，则可以使用https://cors-anywhere.herokuapp.com/之类的东西-在简单的情况下它可以很好地工作。

Answer 2

If you don't have control to the Host, you will need to use a proxy (ie: CORS-Anywhere ) to remove the CORS policy.

  var HttpClient = function() { this.get = function(aUrl, aCallback) { var anHttpRequest = new XMLHttpRequest(); anHttpRequest.onreadystatechange = function() { if (anHttpRequest.readyState == 4 && anHttpRequest.status == 200) aCallback(anHttpRequest.responseText); } anHttpRequest.open( "GET", aUrl, true ); anHttpRequest.send( null ); } } var client = new HttpClient(); client.get('https://cors-anywhere.herokuapp.com/http://app.lotto.pl/wyniki/?type=dl', function(response) { var currentDraw = response; x = currentDraw.split("\\n").slice(1, 7).sort().join(" "); console.log(x); } ); 

More ways to handle the CORS Policy locally are available here .