JavaFX和Spring - bean不会自动装配

Question

我在组合JavaFX和Spring方面遇到了问题.我有简单的JavaFX应用程序,它工作正常.现在我想尝试添加一些Spring.我在Spring Tutorial中使用了JavaFX 2.我的代码:

src/main
|
|_java/mycompany/imageviewer
|   |
|   |_Startup.java
|   |_controller/ImageViewController.java
|   |_dataprovider
|       |impl/DataProviderImpl.java
|   |_config
|       |_SpringFxmlLoader.java
|       |_SpringApplicationConfig.java
|_resources/mycompany/view/ImageViewer.fxml

Startup.java 是主文件:

public class Startup extends Application {

    private static final SpringFxmlLoader loader = new SpringFxmlLoader();

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

    @Override
    public void start(Stage primaryStage) throws Exception {
        ...    
        Parent root = (Parent) loader.load("/mycompany/imageviewer/view/ImageViewer.fxml","mycompany/imageviewer/bundle/bundle");
        Scene scene = new Scene(root);
        ...css etc...
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

ImageviewerController.java:

@Controller
public class ImageViewerController {
    private static final Logger LOG = Logger.getLogger(ImageViewerController.class);
    @FXML
    ...    
    @Autowired
    private DataProvider dataProvider;

    public ImageViewerController() {
        LOG.debug("Controller initialized. DataProvider is null: "+(dataProvider==null));
    }

DataProviderImpl.java:

@Service("dataProvider")
public class DataProviderImpl implements DataProvider {
    private static final Logger LOG = Logger.getLogger(DataProviderImpl.class);

    public DataProviderImpl() {
        LOG.debug("DataProviderImpl initialized.");
    }
    ...methods...
}

我的SpringFxmlLoader在教程中看起来与此类似:

public class SpringFxmlLoader {

    private static final ApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringApplicationConfig.class);

    public Object load(String url, String resources) {
        FXMLLoader loader = new FXMLLoader();
        loader.setControllerFactory(clazz -> applicationContext.getBean(clazz));
        try {
            return loader.load(getClass().getResource(url), ResourceBundle.getBundle(resources));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}

我的SpringApplicationConfig:

@Configuration
@ComponentScan(basePackages = {"mycompany.imageviewer.controller", "mycompany.imageviewer.dataprovider.impl" })
public class SpringApplicationConfig {
    private static final Logger LOG = Logger.getLogger(SpringApplicationConfig.class);

    @Bean
    public DataProvider dataProvider() {
        LOG.debug("Initializing dataProvider via SpringApplicationConfig");
        return new DataProviderImpl();
    }

    @Bean
    public ImageViewerController imageViewerController() {
        LOG.debug("Initializing ImageViewerController via SpringApplicationConfig");
        return new ImageViewerController();
    }
}

在我的应用程序中,我有ImageViewer.fxml绑定控制器:

<AnchorPane fx:controller="mycompany.imageviewer.controller.ImageViewerController" xmlns="http://javafx.com/javafx/8.0.51" xmlns:fx="http://javafx.com/fxml/1" >

当我运行程序时,我得到日志:

DEBUG [main] mycompany.imageviewer.controller.ImageViewerController:74 - Controller initialized. DataProviderImpl is null: true
DEBUG [main] mycompany.imageviewer.dataprovider.impl.DataProviderImpl:22 - DataProviderImpl initialized.
DEBUG [JavaFX Application Thread] mycompany.imageviewer.controller.ImageViewerController:74 - Controller initialized. DataProviderImpl is null: true

这表明,我的控制器初始化了两次,而且dataProvider没有正确绑定.是什么让我困惑,是我不期而遇写错basePackages以ComponentScan这种方式与错的包:

@ComponentScan(basePackages = {"mycompany.imageviewer.dataprovider.controller", "mycompany.imageviewer.dataprovider.dataprovider.impl" })

Bean在SpringApplicationConfig.java运行中初始化方法,我从中获取日志:

2015-09-06 16:52:29,420 DEBUG [main] com.capgemini.starterkit.imageviewer.config.SpringApplicationConfig:19 - Initializing dataProvider via SpringApplicationConfig
2015-09-06 16:52:29,431 DEBUG [main] com.capgemini.starterkit.imageviewer.dataprovider.impl.DataProviderImpl:22 - DataProviderImpl initialized.
DEBUG [main] mycompany.imageviewer.config.SpringApplicationConfig:25 - Initializing ImageViewerController via SpringApplicationConfig
DEBUG [main] mycompany.imageviewer.controller.ImageViewerController:74 - Controller initialized. DataProviderImpl is null: true
DEBUG [JavaFX Application Thread] mycompany.imageviewer.controller.ImageViewerController:74 - Controller initialized. DataProviderImpl is null: true

当我运行basePackages = "com.capgemini.starterkit.imageviewer"效果与第一种情况相同时.我是春天的新手,可能我犯了一些简单的错误,但是我找不到它们,所以如果有人能帮我配置那个很棒的弹簧.:-)

Answer 1

在FXMLLoader.load(URL, ResourceBundle)您所呼叫的方法是一种static方法-因此它实际上不关注了FXMLLoader你化实例,以及因此忽略了controllerFactory它引用您的Spring bean工厂.

重写你的SpringFXMLLoader课程如下:

public class SpringFxmlLoader {

    private static final ApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringApplicationConfig.class);

    public Object load(String url, String resources) {
        FXMLLoader loader = new FXMLLoader();
        loader.setControllerFactory(clazz -> applicationContext.getBean(clazz));
        loader.setLocation(getClass().getResource(url));
        loader.setResources(ResourceBundle.getBundle(resources));
        try {
            return loader.load();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}

这使用将使用您的控制器工厂的实例方法loader.load():即它将使用Spring来实例化控制器.

您看到控制器加载两次的原因是,默认情况下,bean工厂为控制器提供单例作用域并使其热切创建,因此只要您创建bean工厂(applicationContext),它就会创建一个控制器.该控制器将dataProvider初始化(但只有在构造函数完成后才会进行初始化).然后,对静态FXMLLoader.load(...)方法的调用通过常规机制创建第二个控制器(即通过调用其无参数构造函数).该实例不会dataProvider在任何时候进行初始化.

顺便说一句,你可能不希望控制器成为单身人士.如果你要加载你的FXML文件两次,得到两个实例Parent,你可能需要每个实例都有自己的控制器,否则会出现奇怪的行为.我建议将控制器作为原型(这意味着bean工厂将在每次请求时创建一个新实例,而不是重用单个实例).您可以在config类中执行以下操作:

@Configuration
@ComponentScan(basePackages = {"mycompany.imageviewer.controller", "mycompany.imageviewer.dataprovider.impl" })
public class SpringApplicationConfig {
    private static final Logger LOG = Logger.getLogger(SpringApplicationConfig.class);

    @Bean
    public DataProvider dataProvider() {
        LOG.debug("Initializing dataProvider via SpringApplicationConfig");
        return new DataProviderImpl();
    }

    @Bean
    @Scope("prototype")
    public ImageViewerController imageViewerController() {
        LOG.debug("Initializing ImageViewerController via SpringApplicationConfig");
        return new ImageViewerController();
    }
}