Develop Reference

Need help getting a response from API

I formulated this XHR request by converting it from curl.
the curl request works but can't get this one working. plz help.
var url = "https://networkappers.com/api/port.php?ip=172.217.13.238&port=80";
var xhr = new XMLHttpRequest();
xhr.open("GET", url);
xhr.setRequestHeader("Cache-Control", "no-cache");
xhr.setRequestHeader("Referer", "https://www.networkappers.com/tools/open-port-checker");
xhr.onreadystatechange = function() {
if (xhr.readyState === 4) {
console.log(xhr.status);
console.log(xhr.responseText);
}
};
xhr.send();

HTML5 java script XMLHttpRequest status 0 and responseText is empty

I am trying to call web service in html5 javascript. But XMLHttpRequest status value getting ZERO insted of 200 and responseText is empty. help me to solve the issue, My code below
<script type="text/javascript">
var xhr;
function Getdet()
{
try {
xhr = new XMLHttpRequest();
xhr.open('POST', "URL", true); // URL-->Webservice link
xhr.send();
xhr.addEventListener("readystatechange", processRequest, false);
xhr.responseType = 'json';
}
catch(err)
{
alert(err.message);
}
}
function processRequest(e) {
try{
var prn=JSON.stringify(e);
alert("xhr.readyState-->"+xhr.readyState);
alert("xhr.status-->"+xhr.status);
alert("xhr response-->"+ xhr.response);
if (xhr.readyState == 4 && xhr.status == 200) {
var response = JSON.parse(xhr.responseText);
alert(response.ip);
}
}
catch(err)
{
alert(err.message);
}
}
}
</script>

Detect browser tab close without jquery and send some data to php file

I have wrote a script that send some data to an external php file without jquery.
<script type="text/javascript">
var statsPage = 'http://www.my-url.com/response.php';
function ca(c,o,n,t,e,t,u){return p={type:c,userid:o,gender:n}}
ca("pageview", "1", "male");
var params = Object.keys(p).map(function(k) {
return encodeURIComponent(k) + '=' + encodeURIComponent(p[k])
}).join('&')
const req = new XMLHttpRequest();
//req.addEventListener('load' /*callback after req is complete*/);
req.open('GET', statsPage + '?' + params);
req.send();
req.onreadystatechange = function() {
if (req.readyState == XMLHttpRequest.DONE) {
alert(req.responseText);
}
}
</script>
What i also want to do is to send data when the browser tab is closed, so i wrote a script like below but it is not working. I don't get a response from the php file here.
navigator.sendBeacon = navigator.sendBeacon || function () {
var xhr = new XMLHttpRequest();
xhr.open('GET', 'http://www.my-url.com/response.php?pag_title=1');
xhr.send();
xhr.onreadystatechange = function() {
if (xhr.readyState == XMLHttpRequest.DONE) {
alert(xhr.responseText);
}
}
};
I found also this script but it gives me also no response from the response.php file as an alert:
window.onbeforeunload = function() {
var xhr = new XMLHttpRequest();
xhr.open('GET', 'http://www.my-url.com/response.php?pag_titel=1', true);
// If specified, responseType must be empty string or "text"
xhr.responseType = 'test';
xhr.onload = function () {
if (xhr.readyState === xhr.DONE) {
if (xhr.status === 200) {
//console.log(xhr.response);
//console.log(xhr.responseText);
alert(xhr.responseText);
}
}
};
xhr.send(null);
}
EDIT
I did also the following test but now it gives me an alertbox with the value 1 first and then an alert with the response of the function ca (see first part of the code on top for the function). So i think the onbeforeunload is not working here. If i close browser tab i get nothing in response.
window.onbeforeunload = function() {
var xhr = new XMLHttpRequest();
xhr.open('GET', 'http://www.digital-productions.be/dev/analytics/response.php?pag_titel=1', true);
// If specified, responseType must be empty string or "text"
xhr.responseType = 'test';
xhr.onreadystatechange = function() {
if (xhr.readyState == XMLHttpRequest.DONE) {
alert(xhr.responseText);
}
}
xhr.send(null);
}

You can use the beforeunload event to execute code before the user leaves the page, or you could warn them that there is unsaved changes. You can return a message by using e.returnValue = "Message";.
window.addEventListener("beforeunload", function(e) {
//code
});
Here is a link from the mozilla documentation: https://developer.mozilla.org/en/docs/Web/Events/beforeunload

Can't receive in javascript XMLHttpRequest response from java server

Here is my code in javascript
<script type="text/javascript">
startingListener();
function startingListener() {
setInterval(function(){
var xhr = new XMLHttpRequest();
xhr.open("GET", "http://localhost:32081/", false);
xhr.send();
var result = xhr.response;
console.log(result);
}
}, 100);
}
</script>
And my server on Java
public static void main (String... args) throws IOException, Exception {
String clientSentence;
ServerSocket welcomeSocket = new ServerSocket(32081);
while(true)
{
Socket connectionSocket = welcomeSocket.accept();
BufferedReader inFromClient =
new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
PrintWriter outToClient = new PrintWriter(connectionSocket.getOutputStream(), true);
clientSentence = inFromClient.readLine();
System.out.println("Received: " + clientSentence);
System.out.println("begin");
outToClient.println("fu");
System.out.println("Received: done");
}
}
I just want to receive answer string in JS and work with it further.
So when I run server and run JS, they connected and I received in IDE send() from JS
After that I saw in console of Java that begin and done received, but in browser console I didn't see any answer and script just handled. What do I do wrong?
Thank you for your help

Your client code is missing a state change handler and using setInterval with 100 ms it is very heavy on the server. Here is a better JS. Your JAVA issue is another problem. Downvoters: Do comment
function listener() {
var xhr = new XMLHttpRequest();
xhr.open("GET", "http://localhost:32081/", false);
xhr.onreadystatechange = function () {
if(xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
console.log(xhr.responseText);
}
}
}
listener();
If you want to call listener repeatedly, you can do
function listener() {
var xhr = new XMLHttpRequest();
xhr.open("GET", "http://localhost:32081/", false);
xhr.onreadystatechange = function () {
if(xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
if (xhr.responseText != "done") {
console.log("server still busy");
setTimeout(listener,1000); // repeat the call
}
else {
console.log("finally done");
}
}
}
}

Async request with status = 0

I have some issues with async requests. My website and api are on different ports, Access-Control-Allow-Origin header is set on API side correctly (because synchronious requests work just fine).
The following code always returns 'ERR'. I
function load() {
var xhr = new XMLHttpRequest();
xhr.open('GET', 'http://domain:8801/api/', true);
xhr.onreadystatechange = function() {
if (xhr.readyState == 4) {
if (xhr.status != 200) {
alert( "ERR" + " Status: " + xhr.statusText + " Response: "+xhr.responseText ); //always ERR in browser
}
else {
alert( "SUCCESS" );
}
}
};
xhr.send();
}

Set a listener for the returned async
function reqListener() {
console.log(this.responseText);
}
function load() {
var xhr = new XMLHttpRequest();
xhr.addEventListener("load", reqListener);
xhr.open('GET', 'http://domain:8801/api/');
xhr.send();
}
Not putting in true/false makes it async by default
SO this is all wrong and the "submit" button is the issue - and the async operates differently - the sync waits for response, THEN submits while the async does not and it never returns prior to the submit action