Working with FXML loaders

There is only one class responsible for loading FXML—FXMLLoader—but working with it requires care, as shown in the following sections.

Working with resources

Let's look again at loading FXML:

FXMLLoader.load(getClass().getResource("FirstDocument.fxml")); // URL

The load() method's parameter here is a URL to the FXML file during runtime. It usually looks like the following:

jar:file:/path/to/jar/file/FxmlDemo.jar!/demo/FirstDocument.fxml

So, you will almost never set it directly as a String but through the getResource() method. The getResource parameter can be relative to the current class, as in the preceding examples, or absolute to your JAR directory structure, for example:

FXMLLoader.load(getClass().getResource("/demo/FirstDocument.fxml"));

Using absolute paths allows you to store FXML files in a separate folder rather than among the Java code, which is more convenient for complex projects.

Often, the project structure will look like the following:

./src/demo/FirstController...