AJAX脚本不起作用

Question

I cannot get the origin IP address from the httpRequest object using the following JavaScript. xhttp.responseText return a null value. I'd appreciate your help.

 <script type="text/javascript" language="JavaScript">
       var xhttp = new XMLHttpRequest();
       xhttp.onreadystatechange = function() {
           if (xhttp.readyState == 4 && xhttp.status == 0) {
              document.getElementById("LOCAL_IP").value = xhttp.responseText;
           }
       };
       xhttp.open("GET", "http://11.5.2.218:4080/getIP.jsp", true);
       xhttp.send();
  </script>

the getIP.jsp file content is

Your IP is <%=request.getRemoteAddr()%>

Answer 1

Hey,

You need the xhttp.status to be equal to 200, not 0.

For more information about server status codes, read this HTTP status codes tutorial

Try this:

xhttp.onreadystatechange = function() {
  if (xhttp.readyState == 4 && xhttp.status == 200) {
    document.getElementById("LOCAL_IP").value = xhttp.responseText;
  }
};

</div>