Question

美好的一天。我的JavaFX应用程序有一个奇怪的行为。我使用弹簧将控制器注入装载机，但中途变为NULL。我有一个这样的课堂阶段：

@org.springframework.stereotype.Service
public class Stage extends Application {
    private Controller controller;
    private static final Logger logger = LoggerFactory.getLogger(Stage.class);
    @Autowired
    @Lazy
    public Stage(Controller controller){
        logger.debug("constructor");
        logger.debug(controller.toString());
        this.controller = controller;
    }

    public Stage() {
    }

    @Override
    public void start(javafx.stage.Stage primaryStage) throws Exception {
        logger.debug("start(primarystage)");
        FXMLLoader loader = new FXMLLoader();
        URL location = getClass().getResource("/company/sample.fxml");
        loader.setLocation(location);
        logger.debug(loader.toString());
        logger.debug(controller.toString());
        loader.setController(controller);
        Parent parent = loader.load();
        Scene scene = new Scene(parent, 300, 200);
        primaryStage.setScene(scene);
        primaryStage.show();
    }
    public void start(){
        logger.debug("start()");
        launch();
    }
}

这是一个日志：

10:26:42.887 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Finished creating instance of bean 'controller'
10:26:43.035 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Creating shared instance of singleton bean 'stage' <--------------
10:26:43.035 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Creating instance of bean 'stage' <-------------------
10:26:43.040 [main] DEBUG company.ui.Stage - constructor <------ constructor have been executed
10:26:43.040 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Returning cached instance of singleton bean 'controller' <--- spring given him a 'controller' bean
10:26:43.053 [main] DEBUG company.ui.Stage - company.Controller@130161f7 <---- it is not null
10:26:43.054 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Eagerly caching bean 'stage' to allow for resolving potential circular references 
10:26:43.069 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Finished creating instance of bean 'stage'
10:26:43.074 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Returning cached instance of singleton bean 'stage' 
10:26:43.074 [main] DEBUG company.ui.Stage - start() <-- start() have been executed 
10:26:43.323 [JavaFX Application Thread] DEBUG company.ui.Stage - start(primarystage) <------ start(primary stage) have been executed
Exception in Application start method
10:26:43.332 [JavaFX Application Thread] DEBUG company.ui.Stage - javafx.fxml.FXMLLoader@420ac8a9 
Exception in thread "main" java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:875)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$147(LauncherImpl.java:157)
    at com.sun.javafx.application.LauncherImpl$$Lambda$1/793138072.run(Unknown Source)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException <----- controller is null!!!!!
    at company.ui.Stage.start(Stage.java:42)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
    at com.sun.javafx.application.LauncherImpl$$Lambda$50/1910484864.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)

我无法理解它是如何发生的。

使用弹簧时阶段类的奇怪行为

0 个答案: