写真FX

package face7;
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;
import javafx.scene.Group;
import javafx.scene.image.*;
 import javafx.scene.layout.HBox;

import javafx.scene.image.Image;

public class pro extends Application {
    
    Image[] img=new Image[54];
    ImageView imv;
    int s;
    
    

    public static void main(String args) {
        launch(args);
    }
    
    
    @Override
public void start(Stage primaryStage) {
      
for(s=1;s<30;s++){        
img[s] = new Image("http://propaganda-party.com/img/gallery/1305/pc_b/"+s+".jpg");
}

imv = new ImageView(img[1]);
imv.setFitWidth(400);
imv.setFitHeight(400);
imv.setLayoutX(0);
imv.setLayoutY(0);
  
s=1;        

Button btn = new Button("ボタン");
btn.setPrefHeight(50);
btn.setPrefWidth(50);
btn.setLayoutX(400);
btn.setLayoutY(400);



btn.setOnAction(new EventHandler() {
            @Override
            public void handle(ActionEvent event) {
s=s+1;
if(s>52)s=1;
imv.setImage(img[s]);    
}
});



Group root = new Group();
Scene scene = new Scene(root, 500, 500);
        
root.getChildren().add(imv);
root.getChildren().add(btn);
     
primaryStage.setTitle("写真");
primaryStage.setScene(scene);
primaryStage.show();
    }

}