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I have a JavaFX WebView and want to call the method "hello" of the class "JavaBridge" from "test.html" displayed in the webview. Why doesn't this work? I making sure that the "bridge" object only be added to the window.object when the page has been fully rendered, so that is probably not the problem. I can't see any problem with the HTML either.
Here is the HTML code ("test.html"):
<html>
<head>
</head>
<body>
<a href="#click" onclick="bridge.hello()">call java</a>
</body>
</html>
And here is the Java Code:
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.concurrent.Worker;
import javafx.concurrent.Worker.State;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import netscape.javascript.JSObject;
public class HelloWorld extends Application {
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) {
java.net.URI uri = java.nio.file.Paths.get("test.html").toAbsolutePath().toUri();
WebView root = new javafx.scene.web.WebView();
root.getEngine().load(uri.toString());
root.getEngine().
getLoadWorker().
stateProperty().
addListener(new ChangeListener < State > () {
@Override public void changed(ObservableValue ov, State oldState, State newState) {
if (newState == Worker.State.SUCCEEDED) {
System.out.println("READY");
JSObject jsobj = (JSObject) root.getEngine().executeScript("window");
jsobj.setMember("bridge", new JavaBridge());
}
}
});
primaryStage.setScene(new javafx.scene.Scene(root, 800, 600));
primaryStage.show();
}
}
class JavaBridge {
public void hello() {
System.out.println("hello");
}
}
684
When using this bridge feature on Java 10.0.2, I noticed that it was not working consistently. Javascript upcalls wasn't working all the times.
After researching, I found out this OpenJDK bug related to Java Garbage Collector, which seems to happen on regular JDK as well: https://bugs.openjdk.java.net/browse/JDK-8170085
Indeed, according to https://docs.oracle.com/javase/9/docs/api/javafx/scene/web/WebEngine.html, it's recommended to store the bridge into a variable to avoid Java GC to collect the object.
After adding a private variable to the class, the JS to Java calls started to work all the time in my Application.
153
Your inner class should be inside the main class. And it should be public. Like this:
import java.net.URL;
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.concurrent.Worker;
import javafx.concurrent.Worker.State;
import javafx.scene.web.WebView;
import javafx.stage.Stage;
import netscape.javascript.JSObject;
public class HelloWorld extends Application {
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) {
final URL url = getClass().getResource("test.html");
WebView root = new javafx.scene.web.WebView();
root.getEngine().load(url.toExternalForm());
root.getEngine().getLoadWorker().stateProperty().addListener(new ChangeListener<State>() {
@Override
public void changed(ObservableValue ov, State oldState, State newState) {
if (newState == Worker.State.SUCCEEDED) {
System.out.println("READY");
JSObject jsobj = (JSObject) root.getEngine().executeScript("window");
jsobj.setMember("bridge", new JavaBridge());
}
}
});
primaryStage.setScene(new javafx.scene.Scene(root, 800, 600));
primaryStage.show();
}
public class JavaBridge {
public void hello() {
System.out.println("hello");
}
}
}
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