Simple GET rest service works in IE only ( or Postman ) , but not in Chrome , not in Firefox

Question

I have this HTML/bootstrap code ( actually button and "demo" placer ) :

<button type="button"  class="btn btn-primary" 
onclick="displayAll()">Show/Refresh Storage list</button>
<br/>
<p id="demo"></p>

It calls to this JavaScript piece of code :

function displayAll() {
var xmlhttp = new XMLHttpRequest();
var URL1 = 
"http://localhost:8080/MyStore/rest/StoreService/discslist";
URL1 += "?dummy="+  Math.random();
xmlhttp.open("GET",URL1, true);
xmlhttp.send();
xmlhttp.onreadystatechange = function() 
{
    if (xmlhttp.readyState == 4 && xmlhttp.status == 200)
    {
        var discsList = JSON.parse(xmlhttp.responseText);
        myFunction(discsList);
    }
}   
}
function myFunction(atr) {
var txt="";
txt += "<table border='1' class='table table-striped'>"
txt += "<thead><tr><th>id</th><th>Disc Name</th><th>Quantity</th>
<th>price</th></tr></thead>"
    for (x in atr) {
        txt += "<tr><td>" + atr[x].id + "</td>";
        txt += "<td>" + atr[x].name + "</td>";
        txt += "<td>" + atr[x].qnty + "</td>";
        txt += "<td>" + atr[x].price + " $</td></tr>";
    }
    txt += "</table>" 
    document.getElementById("demo").innerHTML = txt;}

So the main idea is to display data returned from Rest service as a table and this is works fine in IE ( BTW , the postman works fine too and i can see the JSON output ) , but in Chrome and Firefox it does not .

During my investigation i found out that onreadystatechange event fires 3 times in IE and only on third time it comes with 4 and 200. In Chrome it fires once , in Firefox twice , but in both cases no 4/200 is sent back from Tomcat. ( Server is Tomcat 8.5. )

Anybody have an idea how to proceed from here and what could be an issue ?

Thanks

Answer 1

Well ,I have found the problem. It is actually related to CORS ( Cross-Origin Resource Sharing ) . I just added CORS filter to web.xml of my application And it works great. This is how to : https://enable-cors.org/server_tomcat.html

Regarding IE why this worked without this : As far as i understand This is because i open html file from my Desktop so IE work in "TRUST ZONE" so no CORS is applied on GET requests