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Java Build a JavaFX Application Build a Pomodoro App Build the State Change Events

Posted by Sharad Shivmath
Sharad Shivmath
14,446 Points

What is @FXML in the code?

Hey,

Sorry, although I saw this on previous videos, I am not clear about what exactly this means? I googled it and came across annotations. I could be wrong. Can some one give another example of this?

Thanks

1 Answer

Jura Streaming
Jura Streaming
8,082 Points
Jura Streaming
Jura Streaming
8,082 Points

@whatever_stuff is annotation indeed, you are right. It is to put simply just metadata. Used for compiler and runtime.

Is is like @Override before method definition says to compiler "Hey, take a look at this, I want to override parent class method by this method. (toString() for example). The value in this is, that compiler will give you a thumbs down if no such method exists in parent. It helps to ensure things fit together as you wanted.

Now the @FXML annotation is same thing, except this time it is for JavaFX, at first compiler does not know anything about this annotation, hence it will be imported from 'import javafx.fxml.FXML;'. And it is to make sure things are connected to stuff in fxml files.

@FXML
private VBox container;

matches up with 'fx:id="container"

<?import javafx.scene.layout.*?>
<?import javafx.scene.shape.SVGPath?>
<VBox stylesheets="/css/main.css"
      xmlns="http://javafx.com/javafx/8"
      xmlns:fx="http://javafx.com/fxml"
      fx:controller="com.teamtreehouse.pomodoro.controllers.Home"
      fx:id="container">
    <children>

Btw, the IntelliJ (perhaps other IDE's too) will even put a link near it to jump to fxml file where fx:id="container" resides.

You can create your own annotations too: https://docs.oracle.com/javase/tutorial/java/annotations/