The code in the listing below has 4 possible outcomes. In my opinion, the application should always have outcome 1.

1) successful run, with loading finished in about a second. Output:
SCHEDULED
RUNNING
SUCCEEDED
1082

2) successful run, but with extremely slow loading (in this case over a minute). Output:
SCHEDULED
RUNNING
SUCCEEDED
60295

3) the application hangs (or at least doesn't finish within 15 minutes). Output:
SCHEDULED
RUNNING

4) loading succeeds, but an exception is thrown. Output:
SCHEDULED
RUNNING
SUCCEEDED
1102
mei 01, 2014 6:24:45 PM com.sun.webkit.network.URLLoader doRun
WARNING: Unexpected error
java.lang.IllegalStateException: Attempt to call defer when toolkit not running
at com.sun.javafx.tk.quantum.QuantumToolkit.defer(QuantumToolkit.java:675)
at com.sun.javafx.webkit.prism.PrismInvoker.invokeOnEventThread(PrismInvoker.java:54)
at com.sun.webkit.network.URLLoader.callBack(URLLoader.java:847)
at com.sun.webkit.network.URLLoader.didReceiveResponse(URLLoader.java:714)
at com.sun.webkit.network.URLLoader.receiveResponse(URLLoader.java:464)
at com.sun.webkit.network.URLLoader.doRun(URLLoader.java:143)
at com.sun.webkit.network.URLLoader.access$000(URLLoader.java:43)
at com.sun.webkit.network.URLLoader$1.run(URLLoader.java:107)
at com.sun.webkit.network.URLLoader$1.run(URLLoader.java:104)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.webkit.network.URLLoader.run(URLLoader.java:104)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:744)


code:

import java.util.concurrent.TimeUnit;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.concurrent.Worker;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class WebEngineIssue extends Application {

private static final String JAVA_API = "http://docs.oracle.com/javase/8/docs/api/";
private static final String JAVAFX_API = "http://docs.oracle.com/javase/8/javafx/api/";

@Override
public void start(final Stage stage) {
long start = System.nanoTime();
WebEngine engine = new WebEngine();
engine.getLoadWorker().stateProperty().addListener((ov, oldState, newState) -> {
System.out.println(newState);
if (newState == Worker.State.SUCCEEDED) {
System.out.println(TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start));
Platform.exit();
}
});
engine.load(JAVA_API);

WebView view = new WebView();
WebEngine viewEngine = view.getEngine();
viewEngine.load(JAVAFX_API);
}

}