通过浏览器为简单HelloWorld应用程序运行JavaFX

Question

I tried following various tutorials for getting a JavaFX hello world app running in a browser. I can't believe it's that hard, so I'm looking for any insight into what I may have done wrong. Some things I've tried and resolved (to rule out the obvious):

• Had to download 32-bit JRE for the browsers and ensure they were using that
• Thus using the latest JRE (7u21); running on Win 7 64-bit
• Checked Windows Control Panel -> Programs -> Java to verify the JRE being used
• Signed the JAR file
• Tried running from local file, found that drive letters weren't recognized, so moved to running via Tomcat 6
• Tried various changes to the codebase and url hrefs, but I believe those are correct.
• Tried in both IE 10 and Chrome

What I ended up with was that loading the .html (which references the jnlp using the JavaFX default javascript) would spin for a while then fail. If I try to load the .jnlp file directly, I get an exception:

ClassNotFoundException: javafx.application.Application

I verified that the jfxrt.jar is in the lib folder of the JRE that the browser is using.

Any insight/suggestions as to what I may be missing at this point? Seems like it must be something obvious/basic at this point, but I'm not seeing it. Thanks.

Answer 1

Just to follow-up, I went ahead and used javafxpackager. That produced a web page that would load the JavaFX application in Chrome. However, it still doesn't work in IE. I'm going to write that off as an IE but since it works in Chrome. What I did learn by looking at the results, though, is there are several things javafxpackager does, and the results of that are not exactly what's described in most of the manual tutorials/examples. Minor differences, but apparently they matter.

Answer 2

It sounds as you don't have the JavaFX starter classes in your JAR (usually done by the Ant script) and don't have the correct JavaFX Manifest entries.

It should not be needed to add the jfxrt.jar as a resource to your JNLP file and you shouldn't have to sign it.

Please show your Manifest file.

The Manifest file should contain at least the following JavaFX entries:

JavaFX-Version: 2.2
JavaFX-Application-Class: yourPackage.YourApplication
Main-Class: com/javafx/main/Main

The JAR should contain the classes of the com.javafx.main package provided by the ant-javafx.jar (see /resources/classes in that Jar). The ant-javafx.jar is provided by the JDK.

Answer 3

I was able to mostly resolve my problem. I'm using Eclipse, not NetBeans, so doing a lot manually. The basic problem was that I had to include the jfxrt.jar as a resource in the jnlp file (and that jar also had to be signed).

My app now runs if I access the jnlp directly, though it still doesn't work via html page. I'll post an update if/when I figure that part out.