Compiling and Running a JavaFX Application

4 Compiling and Running a JavaFX Application

The following steps show you how to compile and run a simple JavaFX application.

Create the following directory tree:
- myapplication
  - src
    - helloworld
  - bin
Run all the commands in these steps in the directory myapplication.

Save the following code in a file named src/helloworld/HelloWorldFX.java:

package helloworld;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
 
public class HelloWorldFX extends Application {
    public static void main(String[] args) {
        launch(args);
    }
    
    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Hello World!");
        Button btn = new Button();
        btn.setText("Say 'Hello World'");
        btn.setOnAction(new EventHandler<ActionEvent>() {
 
            @Override
            public void handle(ActionEvent event) {
                System.out.println("Hello World!");
            }
        });
        
        StackPane root = new StackPane();
        root.getChildren().add(btn);
        primaryStage.setScene(new Scene(root, 300, 250));
        primaryStage.show();
    }
}

Add an environment variable pointing to the lib directory of the JavaFX SDK. For example:
- Linux and macOS:
```
export JAVAFX_SDK=/path/to/javafx_sdk/lib
```
- Windows:
```
set JAVAFX_SDK="C:\path\to\javafx_sdk\lib"
```
Compile HelloWorld.java. In the --module-path command-line option, specify the lib directory of the JavaFX SDK. In the --add-modules command-line option, specify the JavaFX modules that your application uses. For example:
- Linux and macOS:
```
javac --module-path $JAVAFX_SDK --add-modules javafx.controls \
      -d bin HelloWorld.java
```
- Windows:
```
javac --module-path %JAVAFX_SDK% --add-modules javafx.controls ^
      -d bin src/helloworld/HelloWorldFX.java
```
Run the application.
- Linux and macOS:
```
java --module-path $JAVAFX_SDK --add-modules javafx.controls \
     --enable-native-access=javafx.graphics -cp bin helloworld.HelloWorldFX
```
- Windows:
```
java --module-path %JAVAFX_SDK% --add-modules javafx.controls ^
     --enable-native-access=javafx.graphics -cp bin helloworld.HelloWorldFX
```
Note:
Some JavaFX modules, such as javafx.graphics call restricted methods, which causes the Java runtime to print a warning message. This example uses the command-line option --enable-native-access to suppress this warning.
See Restricted Methods in Java Platform, Standard Edition Core Libraries for more information about restricted methods and the --enable-native-access option.

Creating a Custom JRE for a JavaFX Application

You can also download JavaFX JMOD files, which you can use to create a custom runtime image for your JavaFX application.

These steps show you how to create a custom JRE for the HelloWorldFX sample application described in Compiling and Running a JavaFX Application. Run all the commands from the myapplication directory.

In the directory myapplication, create a subdirectory named mods.
Add an environment variable pointing to the directory that contains the JavaFX JMOD files. For example:
- Linux and macOS:
```
export JAVAFX_JMODS=/path/to/javafx_jmods
```
- Windows:
```
set JAVAFX_JMODS="C:\path\to\javafx_jmods"
```

Save the following code in a file named src/module-info.java

module helloworld {
    requires javafx.controls;
    exports helloworld;
}

Compile the HelloWorldFX application as a module:

Linux and macOS

javac --module-path $JAVAFX_MODS -d mods/helloworld \
      src/module-info.java src/helloworld/HelloWorldFX.java

Windows

javac --module-path %JAVAFX_MODS% -d mods\helloworld ^
      src\module-info.java src\helloworld/HelloWorldFX.java

Note:

To compile all Java source files in a directory, use the following command:

Linux and macOS

javac --module-path $JAVAFX_MODS -d mods/helloworld $(find src/ -name "*.java")

Windows

dir /s /b src\*.java > source-files.txt & javac --module-path %JAVAFX_MODS% ^
    -d mods/helloworld @source-files.txt & del source-files.txt

Test the HelloWorldFX modular application by running it:

Linux and macOS

java --module-path $JAVAFX_SDK:mods --enable-native-access=javafx.graphics \
     -m helloworld/helloworld.HelloWorldFX

Windows

java --module-path "%JAVAFX_SDK%;mods" --enable-native-access=javafx.graphics ^
     -m helloworld/helloworld.HelloWorldFX

Create a custom JRE for the HelloWorldFX modular application with jlink:

Linux and macOS

jlink --module-path %JAVAFX_MODS:mods --add-modules helloworld --output helloworld

Windows

jlink --module-path "%JAVAFX_MODS%;mods" --add-modules helloworld --output helloworld

Run HelloWorldFX with the custom JRE you just created:

Linux and macOS

helloworld/bin/java --enable-native-access=javafx.graphics -m helloworld/helloworld.HelloWorldFX

Windows

helloworld\bin\java --enable-native-access=javafx.graphics -m helloworld/helloworld.HelloWorldFX