To reproduce run following code twice. In the first application press "copy to clipboard" and in the second press "paste from clipboard".



import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.Clipboard;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.DataFormat;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class ClipboardSample extends Application {

    public static void main(String[] args) {
        launch(args);
    }
    final static DataFormat DF = new DataFormat("custom.string");
    private Parent getContent() {
        VBox list = new VBox(10);
        Button but = new Button("Copy to clipboard");
        but.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent t) {
                Clipboard cb = Clipboard.getSystemClipboard();
                ClipboardContent cc = new ClipboardContent();
                cc.put(DF, "Hello world!!!");
                cb.setContent(cc);
            }
        });

        list.getChildren().add(but);
        Button but1 = new Button("Paste from clipboard");
        but1.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent t) {
                Clipboard cb = Clipboard.getSystemClipboard();
                System.err.println("###Custom df: " + cb.getContent(DF));
                System.err.println("###Custom df: " +(String) cb.getContent(DF));

            }
        });

        list.getChildren().add(but1);
        return list;
    }

    public void start(Stage stage) {

        stage.setX(100);
        stage.setY(100);
        stage.setWidth(200);
        stage.setHeight(200);
        Scene scene = new Scene(getContent());
        stage.setScene(scene);
        stage.show();
    }
}