将JavaFX与包一起使用会生成“缺少JavaFX应用程序类”错误

Question

I'm working on getting started with JavaFX now that it comes with Java 8 and I've run into a strange issue. When running from the default package, my simple Hello World application runs just fine. However, when putting it into a package, trying to run the program gives me the following error:

Missing JavaFX application class view/JFXHelloWorld

I've included a normal HelloWorld.java file in the view folder and it works just fine.

To clarify, my file structure looks like this:

jfx ----src --------view ------------HelloWorld.java ------------JFXHelloWorld.java ----target --------view ------------HelloWorld.class ------------JFXHelloWorld.class

Where target is the folder that I am putting the compiled files into with the following command:

javac -d target src/view/*.java

Running the normal HelloWorld.java file works just fine:

java -cp target view/HelloWorld Hello, World!

However, running the JavaFX file causes a problem with the ClassLoader:

java -cp target view/JFXHelloWorld Missing JavaFX application class view/JFXHelloWorld

Googling led me to 9 results, all of which are the source code for the JavaFX ClassLoader .

Both HelloWorld.java and JFXHelloWorld.java are declared to be in package view; - is this correct? Any help would be appreciated.

Answer 1

My problem actually was in the command-line call to run HelloWorld.

I should instead be calling the following:

java -cp target view.HelloWorld
java -cp target view.JFXHelloWorld

For some reason, it allows you to run view/HelloWorld when it shouldn't.

Answer 2

Maybe, your problem it's that JFXHelloWorld it's extending from Application and you aren't setting the classpath correctly. Are you using Java8 or any previous Java release?