Is there any way to check reachability test of server in jQuery

问题

Is there any way to check reachability test of server .If application not able to connect server then it show a alert? is there any thing method to check.. I check the internet connection .If there is no connection then i am showing a alert .But if there is an connection but there is no reachability of server than how can i handle this.? I am checking like this connection status..!!

setInterval(function () {
    connectionStatus = navigator.onLine ? 'online' : 'offline';
    if(connectionStatus=="offline"){
        // alert("There is no connection");
    }
}, 100);



$.ajax({url: "192.168.12.171",
        dataType: "jsonp",
        statusCode: {
            200: function (response) {
                alert('status 200');
            },
            404: function (response) {
                alert('status  404 ');
            }
        }                        
 });

回答1:

To test if your server is up you will need to connect to it and check status massage:

$.ajax('LINK GOES HERE', {
  statusCode: {
    404: function() {
      alert('Not working');
    },
    200: function() {
      alert('Working');
    }
  }
});

Working jsFiddle example: http://jsfiddle.net/Gajotres/PMrDn/47/

$.ajax({url: "http://api.themoviedb.org/2.1/Movie.search/en/json/23afca60ebf72f8d88cdcae2c4f31866/The Goonies",
        dataType: "jsonp",
        statusCode: {
            200: function (response) {
                alert('status 200');
            },
            404: function (response) {
                alert('status  404 ');
            }
        }                        
 });

EDIT :

Use this:

$.ajax({url: "http://192.168.12.171",
        type: "HEAD",
        timeout:1000,
        statusCode: {
            200: function (response) {
                alert('Working!');
            },
            400: function (response) {
                alert('Not working!');
            },
            0: function (response) {
                alert('Not working!');
            }              
        }
 });

Working example: http://jsfiddle.net/Gajotres/PMrDn/48/

回答2:

One hacky way that should work would be to load an image (or font, style, javascript) from the server and check whether or not that image loads. This method would of course only work as long as there is something to load from the server that is not restricted by CORS policies.

来源：https://stackoverflow.com/questions/17877639/is-there-any-way-to-check-reachability-test-of-server-in-jquery