JavaFX UI组件——Password Field

详解：https://docs.oracle.com/javase/8/javafx/user-interface-tutorial/password-field.htm

代码示例：

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class PasswordFiledSample extends Application {

    final Label message = new Label("");

    @Override
    public void start(Stage stage) {
        Group root = new Group();
        Scene scene = new Scene(root, 260, 80);
        stage.setScene(scene);
        stage.setTitle("Password Field Sample");

        VBox vb = new VBox();
        vb.setPadding(new Insets(10, 0, 0, 10));
        vb.setSpacing(10);
        HBox hb = new HBox();
        hb.setSpacing(10);
        hb.setAlignment(Pos.CENTER_LEFT);

        Label label = new Label("Password");
        final PasswordField pb = new PasswordField();  
        pb.setText("Your password");

        pb.setOnAction((ActionEvent e) -> {
            if (!pb.getText().equals("T2f$Ay!")) {
                message.setText("Your password is incorrect!");
                message.setTextFill(Color.rgb(210, 39, 30));
            } else {
                message.setText("Your password has been confirmed");
                message.setTextFill(Color.rgb(21, 117, 84));
            }
            pb.clear();
        });

        hb.getChildren().addAll(label, pb);
        vb.getChildren().addAll(hb, message);

        scene.setRoot(vb);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}