Frequently encountered issues

var engine = Engine.newInstance(
        EngineOptions.newBuilder(renderingMode)
                     .passwordStore(PasswordStore.BASIC)
                     .build());

val engine = Engine.newInstance(
        EngineOptions.newBuilder(renderingMode)
                     .passwordStore(PasswordStore.BASIC)
                     .build())

ObjectClosedException

Service objects in the library API may be closed. An attempt to call a closed object leads to an ObjectClosedException exception.

In this guide, we explain common scenarios when a service object can be closed and what you can do about it.

Closed Engine

The topmost object in JxBrowser is Engine . There are two situations when it can be closed:

• The Engine::close() method is called;
• An error occurs in the Main Chromium process.

If you close an engine, all objects associated with it such as profiles, browsers, frames, etc. will be closed automatically. So, after the engine is closed, regardless of the reason, make sure not to use any of the objects associated with the closed engine.

If an error occurs in the Main Chromium process, the process will be terminated and the engine is closed. When it happens the library generates crash dump files and stores them in a specific directory. Use the EngineCrashed event to be notified when it happens.

In this case, please report the issue and attach the crash dump files .

Deleted Profile

Profiles can be deleted by calling the Profiles::delete() method.

If you delete a profile, all objects associated with it such as cookie store, browsers, frames, DOM/JS objects, etc. are closed automatically. So, after you delete a profile, make sure not to use any of the objects associated with the deleted profile.

Closed Browser

There are two situations when Browser can be closed:

• The Browser::close() method is called;
• JavaScript closes the window.

If you close a browser, all objects associated with it such as navigation, text finder, frames, DOM/JS, etc. will be closed automatically. So, after the browser is closed, make sure not to use any of the objects associated with the closed browser.

The window.close() method in JavaScript can only close a browser that was opened by another script. If you expect this to happen, consider checking the browser status before using it.

Please note that when JavaScript closes the browser Java discovers it with a slight delay. If the browser is already closed but Java is not yet notified, the attempt to use the closed browser will lead to ObjectClosedException .

Unloaded web page

Each loaded web page has a main frame and child frames. When navigating to a web page, the browser unloads the previously loaded page and deletes all the frames and DOM/JS objects in it.

Make sure to not use DOM and JavaScript objects after the web page gets unloaded. Use the navigation events to get notified.

Please note that Java receives navigation events with a slight delay. If the page is already unloaded, but Java is not yet notified, the attempt to use deleted/closed objects will lead to ObjectClosedException .

Terminated render process

In Chromium, frames reside in render processes . When the render process is terminated, the frame is deleted. When the frame is deleted the web page, its DOM and JavaScript objects are deleted and closed too.

Use the RenderProcessTerminated event to get notified when the process is terminated. If the process is terminated unexpectedly, please report the issue and attach the generated crash dump files .

If it is terminated normally, no action is required.

InaccessibleObjectException in Swing BrowserView

When Swing BrowserView is focused, you can see the following exception in console output:

Exception in thread "AWT-EventQueue-0" java.lang.reflect.InaccessibleObjectException: Unable to make static synchronized void java.awt.KeyboardFocusManager.setMostRecentFocusOwner(java.awt.Window,java.awt.Component) accessible: module java.desktop does not "opens java.awt" to unnamed module 
        at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354)
        at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
        at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199)
        at java.base/java.lang.reflect.Method.setAccessible(Method.java:193)

This happens because JxBrowser uses private API from the java.awt package. Java 17 and higher does not allow accessing the internals of a module from other modules. To avoid this exception, you should use the --add-opens switch along with the corresponding package in the JVM arguments:

--add-opens=java.desktop/java.awt=ALL-UNNAMED
JxBrowser