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How to debug JavaFX webview in 2022

How to debug a JavaFX webview?
I find two ways,
one is to attach external chrome debugger to JavaFX webview.
Another is to inject firebug javascript.
Method#1 seems to use a bit of hacks like set access to private fields etc.
Method#2 depends on firebuglite which seems to be obsolete now.
How should this be done in 2022. Are there any other methods, or better methods?
I am trying firebug lite approach as of now, and have made the javascript part of the maven project and trying to inject it as a string versus an external URL, because firebug seems to be properly public hosted nowhere now.
Refering to https://stackoverflow.com/a/18396900/2448015
This is where I am right now :
package xyz.jphil.internal_browser;
import com.sun.net.httpserver.HttpContext;
import com.sun.net.httpserver.HttpServer;
import java.net.InetSocketAddress;
import javafx.scene.web.WebEngine;
import netscape.javascript.JSObject;
/**
*
* #author Ivan
*/
public class WebkitDebugUtils {
private static int resourcesPort = 0;
public static void createHttpServerForLocalFiles() {
int portStart = 64321, endPort = 65534;
resourcesPort = portStart + (int) ((endPort * 1d - portStart * 1d) * Math.random());
System.out.println("Starting internal server on " + resourcesPort);
try {
HttpServer server = HttpServer.create(new InetSocketAddress(resourcesPort), 0);
HttpContext context = server.createContext("/");
context.setHandler((req) -> {
try (req) {
var p = req.getRequestURI();
System.out.println("Serving # localhost:"+resourcesPort+" "+p);
var s = WebkitDebugUtils.class.getResourceAsStream(p.toString()).readAllBytes();
req.sendResponseHeaders(200, s.length);
req.getResponseBody().write(s);
}catch(Exception a){
a.printStackTrace();
}
});
server.start();
} catch (Exception e) {
e.printStackTrace();
}
}
public static class JavaBridge {
public void log(String text) {
System.out.println(text);
}
}
// Maintain a strong reference to prevent garbage collection:
// https://bugs.openjdk.java.net/browse/JDK-8154127
private final static JavaBridge bridge = new JavaBridge();
public static void enableDebug(final WebEngine e) {
JSObject window = (JSObject) e.executeScript("window");
window.setMember("java", bridge);
e.executeScript("""
console.log = function(message)
{
java.log(message);
};""");
e.executeScript("console.log('console.log enabled');");
}
public static void enableFirebug(final WebEngine e) {
var firebugurl = "http://localhost:"+resourcesPort+"/firebug-lite/firebug-lite.js";
//https://raw.githubusercontent.com/stefanXO/firebug-lite/master/firebug-lite.js
//https://lupatec.eu/getfirebug/firebug-lite-compressed.js
var script= """
console.log("Inside script block");
if (!document.getElementById("FirebugLite")) {
E = document["createElement" + "NS"] && document.documentElement.namespaceURI;
E = E ?
document["createElement" + "NS"](E, "script") :
document["createElement"]("script");
E["setAttribute"]("id", "FirebugLite");
E["setAttribute"]("src", "{$firebugurl}#startOpened");
E["setAttribute"]("FirebugLite", "4");
(
document["getElementsByTagName"]("head")[0]
||
document["getElementsByTagName"]("body")[0]
).appendChild(E);
E = new Image();
E["setAttribute"]("src", "{$firebugurl}#startOpened");
}
console.log("executed script block");
""".replace("{$firebugurl}", firebugurl);
System.out.println("+++firebug thing+++");
System.out.println(script);
System.out.println("---firebug thing---");
e.executeScript(script);
}
}
Main method of the application
//...
public static void main(String[]args){
WebkitDebugUtils.createHttpServerForLocalFiles();
launch(args);
}
//...
In the JavaFx Stage initializing code section
#Override
public void start(final Stage primaryStage) throws Exception {
// ....
wv = new WebView();
// ....
javafx.scene.web.WebEngine e = wv.getEngine();
// ....
e.getLoadWorker().stateProperty().addListener((ov, t, t1) -> WebkitDebugUtils.enableDebug(e));
e.documentProperty().addListener((ov, t, t1) -> WebkitDebugUtils.enableFirebug(e));
// ....
}
I am serving the files for firebug from the resources folder of the jar
Snippter of the custom firebug.js file
console.log("inside firebug-lite");
(function(){
//...
//firebug lite 1.4.0 code
//..
})();
console.log("outside firebug-lite");
Output
Starting internal server on 65148
console.log enabled
console.log enabled
// some application specific output
+++firebug thing+++
if (!document.getElementById("FirebugLite")) {
E = document["createElement" + "NS"] && document.documentElement.namespaceURI;
E = E ?
document["createElement" + "NS"](E, "script") :
document["createElement"]("script");
E["setAttribute"]("id", "FirebugLite");
E["setAttribute"]("src", "http://localhost:65148/firebug-lite/firebug-lite.js#startOpened");
E["setAttribute"]("FirebugLite", "4");
(
document["getElementsByTagName"]("head")[0]
||
document["getElementsByTagName"]("body")[0]
).appendChild(E);
E = new Image();
E["setAttribute"]("src", "http://localhost:65148/firebug-lite/firebug-lite.js#startOpened");
}
---firebug thing---
Inside script block
executed script block
Serving # localhost:65148 /firebug-lite/firebug-lite.js
// some application specific output
console.log enabled
Summary:
nothing is happening, nothing is showing up in the console, I don't know the error, firebug is not even opening.
Update2:
I think I am using the wrong version of firebug 1.5 or something
and the old version I don't see any HTML file and thus it is dependent on the default website which is down at the moment.

You can simply inject firebug-lite after loading your webpage.
I've tested on windows 10 with correto 18.0.2 JDK.
Here's an example: (Page can take some time to load)
package com.example.demo;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.VBox;
import javafx.scene.web.WebView;
import javafx.stage.Stage;
import javafx.scene.web.WebEngine;
import javafx.concurrent.Worker.State;
public class HelloApplication extends Application {
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage myStage) {
System.out.println("Demo for firebugLite");
WebView myWebView = new WebView();
myWebView.minHeight(1050);
myWebView.prefWidth(1950);
myWebView.prefHeight(1070);
myWebView.minWidth(1050);
final WebEngine myWebEngine = myWebView.getEngine();
myWebEngine.getLoadWorker().stateProperty()
.addListener((obs, oldValue, newValue) -> {
if (newValue == State.SUCCEEDED) {
System.out.println("finished loading");
myWebEngine.executeScript("var firebug=document.createElement('script');firebug.setAttribute('src','https://lupatec.eu/getfirebug/firebug-lite-compressed.js');document.body.appendChild(firebug);(function(){if(window.firebug.version){firebug.init();}else{setTimeout(arguments.callee);}})();void(firebug);");
}
});
myWebEngine.load("https://lupatec.eu/getfirebug/");
VBox myBox = new VBox(myWebView);
Scene myScene = new Scene(myBox, 1050, 600);
myStage.setScene(myScene);
myStage.show();
}
}
Result:

Simulate page click with coordinates (x,y)

How do I simulate a click with coordinates on HtmlPage then get the result a HtmlPage?
I want to click a button without an id or a name
I'm using the library com.gargoylesoftware.htmlunit

not sure about specific system or browser settings, but in general you can do this by following:
import java.awt.event.*;
import java.awt.Robot;
public class test {
int xparam=50;
int yparam=100;
public static void main(String args[]) {
Robot mybot = null;
try {
mybot = new Robot();
} catch (Exception failed) {
System.err.println("Failed instant. Robot: " + failed);
}
int maske = InputEvent.BUTTON1_DOWN_MASK;
mybot.mouseMove(xparam,yparam);
mybot.mousePress(maske);
mybot.mouseRelease(maske);
}
}
For a smoother solution take a look at this ;

No,You can't click button with coordinates(X,Y).
Please specify the element other attributes because it can be click with help of other attribute

Set Icon Image in Java

I have been searching everywhere on how to set the icon image in Java, and it always ends up not working or it gives me errors. Here, in my main method is where I put the code:
public static void main(String[] args) {
Game game = new Game();
// This right here!
game.frame.setIconImage(new ImageIcon("/Icon.png").getImage());
game.frame.setResizable(false);
game.frame.setTitle(title);
game.frame.add(game);
game.frame.pack();
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null);
game.frame.setVisible(true);
}
My path for the image is "%PROJECT%/res/Image.png" and I just use /Image.png to go ahead and access my res folder (as I have done in other parts of my project) I have even converted it into an icon file, and tried that, but all it decides is to use the default Java icon.

Your problem is often due to looking in the wrong place for the image, or if your classes and images are in a jar file, then looking for files where files don't exist. I suggest that you use resources to get rid of the second problem.
e.g.,
// the path must be relative to your *class* files
String imagePath = "res/Image.png";
InputStream imgStream = Game.class.getResourceAsStream(imagePath );
BufferedImage myImg = ImageIO.read(imgStream);
// ImageIcon icon = new ImageIcon(myImg);
// use icon here
game.frame.setIconImage(myImg);

Use Default toolkit for this
frame.setIconImage(Toolkit.getDefaultToolkit().getImage("Icon.png"));

I use this:
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
public class IconImageUtilities
{
public static void setIconImage(Window window)
{
try
{
InputStream imageInputStream = window.getClass().getResourceAsStream("/Icon.png");
BufferedImage bufferedImage = ImageIO.read(imageInputStream);
window.setIconImage(bufferedImage);
} catch (IOException exception)
{
exception.printStackTrace();
}
}
}
Just place your image called Icon.png in the resources folder and call the above method with itself as parameter inside a class extending a class from the Window family such as JFrame or JDialog:
IconImageUtilities.setIconImage(this);

The below method works well on Java 7 and above.
JFrame frame = new JFrame("MyAPP");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
frame.setIconImage(ImageIO.read(YourClass.class.getResourceAsStream("/icon.png")));
} catch (IOException ex) {
ex.printStackTrace();
}
frame.setVisible(true);
Park your icon.png image file to /src/main/resources.

eclipse plugin does not work after update to juno (eclipse 4)

I created an eclipse plugin that will hook into the save action to create a minified javascript file with the goolge closure compiler. See files below.
That worked until eclipse 3.7.2. Unfortunately now in eclipse 4.2.1 it seems that this creates an endless loop sometimes. The job "compile .min.js" (line 64 in ResourceChangedListener.java) seems the be the cause. It results in the case that the workspaced starts to build over and over. I guess this is because that job creates or changes a file triggering the workspace build again, which again triggers the job which triggers the build and so on.
But I can not figure out how to prevent this.
// Activator.java
package closure_compiler_save;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.osgi.framework.BundleContext;
/**
* The activator class controls the plug-in life cycle
*/
public class Activator extends AbstractUIPlugin {
// The plug-in ID
public static final String PLUGIN_ID = "closure-compiler-save"; //$NON-NLS-1$
// The shared instance
private static Activator plugin;
/**
* The constructor
*/
public Activator() {
}
#Override
public void start(BundleContext context) throws Exception {
super.start(context);
Activator.plugin = this;
ResourceChangedListener listener = new ResourceChangedListener();
ResourcesPlugin.getWorkspace().addResourceChangeListener(listener);
}
#Override
public void stop(BundleContext context) throws Exception {
Activator.plugin = null;
super.stop(context);
}
/**
* Returns the shared instance
*
* #return the shared instance
*/
public static Activator getDefault() {
return plugin;
}
}
// ResourceChangedListener.java
package closure_compiler_save;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IResourceChangeEvent;
import org.eclipse.core.resources.IResourceChangeListener;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
public class ResourceChangedListener implements IResourceChangeListener {
public void resourceChanged(IResourceChangeEvent event) {
if (event.getType() != IResourceChangeEvent.POST_CHANGE)
return;
IResourceDelta delta = event.getDelta();
try {
processDelta(delta);
} catch (CoreException e) {
e.printStackTrace();
}
}
// find out which class files were just built
private void processDelta(IResourceDelta delta) throws CoreException {
IResourceDelta[] kids = delta.getAffectedChildren();
for (IResourceDelta delta2 : kids) {
if (delta2.getAffectedChildren().length == 0) {
if (delta.getKind() != IResourceDelta.CHANGED)
return;
IResource res = delta2.getResource();
if (res.getType() == IResource.FILE && "js".equalsIgnoreCase(res.getFileExtension())) {
if (res.getName().contains("min"))
return;
compile(res);
}
}
processDelta(delta2);
}
}
private void compile(final IResource res) throws CoreException {
final IPath fullPath = res.getFullPath();
final IPath fullLocation = res.getLocation();
final String fileName = fullPath.lastSegment().toString();
final String outputFilename = fileName.substring(0, fileName.lastIndexOf(".")).concat(".min.js");
final String outputPath = fullPath.removeFirstSegments(1).removeLastSegments(1).toString();
final IProject project = res.getProject();
final IFile newFile = project.getFile(outputPath.concat("/".concat(outputFilename)));
Job compileJob = new Job("Compile .min.js") {
public IStatus run(IProgressMonitor monitor) {
byte[] bytes = null;
try {
bytes = CallCompiler.compile(fullLocation.toString(), CallCompiler.SIMPLE_OPTIMIZATION).getBytes();
InputStream source = new ByteArrayInputStream(bytes);
if (!newFile.exists()) {
newFile.create(source, IResource.NONE, null);
} else {
newFile.setContents(source, IResource.NONE, null);
}
} catch (IOException e) {
e.printStackTrace();
} catch (CoreException e) {
e.printStackTrace();
}
return Status.OK_STATUS;
}
};
compileJob.setRule(newFile.getProject()); // this will ensure that no two jobs are writing simultaneously on the same file
compileJob.schedule();
}
}

After I setup a blank eclipse classic environment, started a new eclipse plugin project there and recreated all files it works again partly.
In this environment starting a debug session I can save .js files and .min.js files are created automatically.
So far so good!
But when I install the plugin to my real developing eclipse environment automatic saving does not work.
At least one step further!
Step 2:
There were some files not included in the build obviously needed, like manifest. No idea why they were deselected.
Anyway it seems just setting up a blank eclipse 4 classic and going through the eclipse plugin wizard fixed my original problem. I still would love to know what was the actual problem...

JApplet lacking full functionality in browser

I have a Java JApplet that functions perfectly when eclipse runs it but dissapoints in a browser.
The applet is working fine in the browser up to the point at which the only JButton is pressed. At which point, something should happen, but, in the browser, nothing happens at all apart from the button shows it has been pressed. This doesn't happen when eclipse runs it.
Here is the code:
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.HeadlessException;
import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JTextArea;
import org.bukkit.configuration.ConfigurationSection;
import org.bukkit.configuration.InvalidConfigurationException;
import org.bukkit.configuration.file.YamlConfiguration;
public class OverviewGenerator extends JApplet {
int state = 0;
JTextArea label = new JTextArea();
JButton button = new JButton();
String pluginYML;
YamlConfiguration yml = new YamlConfiguration();
String page;
public ActionListener buttonListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if(state == 0) {
try {
pluginYML = (String) Toolkit.getDefaultToolkit().getSystemClipboard().getData(DataFlavor.stringFlavor);
} catch (HeadlessException e1) {
e1.printStackTrace();
} catch (UnsupportedFlavorException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
try {
yml.loadFromString(pluginYML);
} catch (InvalidConfigurationException e1) {
e1.printStackTrace();
}
state = 1;
}else {
generatePage();
Toolkit toolkit = Toolkit.getDefaultToolkit();
Clipboard clipboard = toolkit.getSystemClipboard();
StringSelection strSel = new StringSelection(page);
clipboard.setContents(strSel, null);
state = 0;
}
refreshComponents();
}
};
/**
*
*/
private static final long serialVersionUID = 3470279389867972761L;
public void init() {
makeGui();
}
private void makeGui() {
label.setWrapStyleWord(true);
label.setLineWrap(true);
label.setBackground(Color.CYAN);
label.setEditable(false);
GridLayout layout = new GridLayout();
layout.setRows(2);
layout.setColumns(1);
getContentPane().setLayout(layout);
refreshComponents();
getContentPane().add(label);
getContentPane().add(button);
button.addActionListener(buttonListener);
}
private void refreshComponents() {
if(state==0) {
label.setText("Copy your plugin.yml into the clipboard then press done!");
button.setText("Done");
}else if(state == 1) {
label.setText("Now press the button to copy your template BukkitDev overview into your clipboard!");
button.setText("Copy");
}
}
private void generatePage() {
page = "";
page += "== "+yml.getString("name")+" ==\n";
if(yml.contains("description")) {
page += "\n//"+yml.getString("description")+"//\n\n\n";
}
if(yml.contains("commands")) {
page += "== Commands ==\n";
for(String command : yml.getConfigurationSection("commands").getKeys(false)) {
page += "\n=== "+command+" ===\n\n";
if(yml.contains("commands."+command+".description")) {
page += "//"+yml.getString("commands."+command+".description")+"//\n";
}
if(yml.contains("commands."+command+".usage")) {
page += "Usage: "+yml.getString("commands."+command+".usage")+"\n";
}
}
page += "\n";
}
if(yml.contains("permissions")) {
YamlConfiguration editedYml = new YamlConfiguration();
try {
editedYml.loadFromString(pluginYML.replace(".", "≠"));
} catch (InvalidConfigurationException e) {
e.printStackTrace();
}
ConfigurationSection permissions = editedYml.getConfigurationSection("permissions");
page += "== Permissions ==\n";
for(String permission : permissions.getKeys(false)) {
page += "\n=== "+permission.replace('≠', '.')+" ===\n\n";
if(editedYml.contains("permissions."+permission+".description")) {
page += "//"+editedYml.getString("permissions."+permission+".description").replace('≠', '.')+"//\n";
}
}
page += "\n\n\n";
}
page += "//Got any suggestions?//";
}
}
The code above is slightly outdated, I have added in the 'invoke later' code now! I am having trouble showing the Java console but I believe the error may be when the clipboard is accessed.

For security reasons, there are two ways that an applet can access the clip-board.
The applet is digitally signed by the developer, and trusted by the end user.
The applet uses the services of the JNLP API to access the clipboard. That is available in more recent JREs, Sun's 1.6.0_10+, for example.
There is potentially a 3rd way to get data to the applet that involves
having the user paste directly into an HTML form field
then use JS to transfer the data to the applet.
That could be done in a sand-boxed applet, and before the JRE that supports the JNLP API services. OTOH that would mean more clicks for the user, and more setting up.
//Got any suggestions?//
Beyond 'ask a more specific question' I might also suggest:
Enable the Java Console. That information is vital for debugging applets.
Read Copy in sand-boxed app. in 1.6.0_24+ for more details of the problem with clipboard access in applets, and strategies to copy data out of an applet using JS and other techniques.

Oracle released Java 6 Update 24 in February 2011 to remedy 21 vulnerabilities. As part of this security release, the ability to copy & paste from a computer's clipboard into a Java applet has been disabled.
To fix this issue there are 2 solutions:
Create a digital signature for the applet.
Work around: If you do not want to work with the digital signature, add to your java.policy file the following line: permission java.awt.AWTPermission "accessClipboard"
If you want to see an example of Java Applet working with a signed certificate you can looke here (the applet accepts paste action from clipboard which is not allowed to unsigned applets) : http://sqlinform.com/free_online_sw.html