下雨动效可以使用JavaFX的动画功能来实现。下面是一个简单的示例代码，实现了一个下雨的动画效果：

import javafx.animation.Animation;
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Line;
import javafx.stage.Stage;
import javafx.util.Duration;import java.util.Random;public class RainAnimation extends Application {private static final int WIDTH = 800;private static final int HEIGHT = 600;private static final int NUM_RAINDROPS = 100;@Overridepublic void start(Stage primaryStage) {primaryStage.setTitle("Rain Animation");Group root = new Group();Random random = new Random();for (int i = 0; i < NUM_RAINDROPS; i++) {int startX = random.nextInt(WIDTH);