JavaFX Location is not set error message [duplicate]

Question

I had this problem and found this post. My issue was just a file name issue.

FXMLLoader(getClass().getResource("/com/companyname/reports/" +
report.getClass().getCanonicalName().substring(18).replaceAll("Controller", "") +
".fxml"));

Parent root = (Parent) loader.load();

I have an xml that this is all coming from and I have made sure that my class is the same as the fxml file less the word controller.

I messed up the substring so the path was wrong...sure enough after I fixed the file name it worked.

To make a long story short I think that the problem is either the filename is named improperly or the path is wrong.

ADDITION: I have since moved to a Maven Project. The non Maven way is to have everything inside of your project path. The Maven way which was listed in the answer below was a bit frustrating at the start but I made a change to my code as follows:

FXMLLoader loader = new FXMLLoader(ReportMenu.this.getClass().getResource("/fxml/" + report.getClass().getCanonicalName().substring(18).replaceAll("Controller", "") + ".fxml"));

I know this is a late answer, but I hope to help anyone else who has this problem. I was getting the same error, and found that I had to insert a / in front of my file path. The corrected function call would then be:

FXMLLoader myLoader = new FXMLLoader(getClass().getResource("/createCategory.fxml"));
//                                                           ^

I was getting this exception and the "solution" I found was through Netbeans IDE, simply:

1. Right-click -> "Clean and Build"
   
2. Run project again

I don't know WHY this worked, but it did!

I converted a simple NetBeans 8 Java FXML application to the Maven-driven one. Then I got problems, because the getResource() methods weren't able to find the .fxml files. In mine original application the fxmls were scattered through the package tree - each beside its controller class file. After I made Clean and build in NetBeans, I checked the result .jar in the target folder - the .jar didn't contain any fxml at all. All the fxmls were strangely disappeared.

Then I put all fxmls into the resources/fxml folder and set the getResource method parameters accordingly, for example: FXMLLoader(App.class.getClassLoader().getResource("fxml/ObjOverview.fxml")); In this case everything went OK. The fxml folder appeared int the .jar's root and it contained all my fxmls. The program was working as expected.