We observe low startup performance of our application, when it is deployed on our webserver. During development in eclipse the performance is fine. We found out that the issue is related to frequent appearence of the following messages in the console:
network: Cacheeintrag nicht gefunden [URL: http://localhost/Ensemble/, Version: null]
network: Cacheeintrag nicht gefunden [URL: http://localhost/Ensemble/META-INF/services/javax.xml.stream.XMLInputFactory, Version: null]
network: Verbindung von http://localhost/Ensemble/META-INF/services/javax.xml.stream.XMLInputFactory mit Proxy=DIRECT wird hergestellt
network: Verbindung von socket://localhost:80 mit Proxy=DIRECT wird hergestellt

So a classloader tries to load the class javax.xml.stream.XMLInputFactory from the codebase location. Obviously a core-java class will never be deployed there.

Apparently every call to FXMLLoader.load() creates a XMLInputFactory by calling XMLInputFactory.newInstance(), which in turn calls javax.xml.datatype.FactoryFinder.findJarServiceProvider, which causes the network roundtrip.

We were able to reproduce the problem in the Ensemble application with the following steps:
1. At the beginning of the start method in class Ensemble2.java load any FXML or simply add the following line:
XMLInputFactory.newInstance();
2. Compile and deploy the application on a webserver (I used apache from xampp)
3. Enable java tracing and console
4. Start the jnlp from firefox file
5. The above message is logged in the java console and in the webservers access.log


The problem seems to be related with the contextClassloader. So as a workaround we set the contextClassloader to null before loading any FXMLs like this:

FXMLLoader loader = new FXMLLoader(EditorFX.class.getResource("/fxml/" + fxml));
ClassLoader oldContextClassloader = null;
Object result = null;
try {
oldContextClassloader = Thread.currentThread().getContextClassLoader();
Thread.currentThread().setContextClassLoader(null);
loader.load();
} finally {
if(oldContextClassloader != null)
Thread.currentThread().setContextClassLoader(oldContextClassloader);
}
....