启动Web应用程序Spring时从数据库加载后初始化属性

Question

当前，我的应用程序加载了一个属性文件，该文件具有以逗号分隔的不同属性，

property=propertyA,propertyB,propertyC

我有一个代码，可以加载属性文件并将其分配为以下应用程序属性：

public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    private String[] properties;

    private PropertySource propertySource;

    public WebAppInitializer() {
            propertySource = getPropertySource();
            String propertyStr = (String) propertySource.getProperty("property");
            List<String> list = Lists.newArrayList(Splitter.on(',').trimResults().omitEmptyStrings().split(propertyStr));
            properties = list.toArray(new String[list.size()]);
        }
    }

    //    @Override
    public void onStartup(ServletContext ctx) throws ServletException {
        super.onStartup(ctx);

    }
protected WebApplicationContext createRootAppContext() {
    Class[] configClasses = this.getRootConfigClasses();
    if (!ObjectUtils.isEmpty(configClasses)) {
        AnnotationConfigWebApplicationContext rootAppContext = new AnnotationConfigWebApplicationContext();
        MyPropertySource.addToEnvironment(rootAppContext.getEnvironment());
        rootAppContext.getEnvironment().getPropertySources().addFirst(propertySource);
        rootAppContext.getEnvironment().setActiveProfiles(properties);
        rootAppContext.register(configClasses);
        return rootAppContext;
    } else {
        return null;
    }
}

protected WebApplicationContext createServletAppContext() {
    AnnotationConfigWebApplicationContext servletAppContext = new AnnotationConfigWebApplicationContext();
    servletAppContext.getEnvironment().setActiveProfiles(properties);
    Class[] configClasses = this.getServletConfigClasses();
    if (!ObjectUtils.isEmpty(configClasses)) {
        servletAppContext.register(configClasses);
    }
    return servletAppContext;
}
}

现在，我们正在将这些属性迁移到Db，并希望从数据库中加载。我最初认为是添加以下代码：

        @Autowired
        PropertyRepository propertyRepository;
    public WebAppInitializer() {
                List<String> listDB = propertyRepository.getProperties();
                if(listDB.isEmpty()) {
    propertySource = getPropertySource();
                String propertyStr = (String) propertySource.getProperty("property");
                List<String> list = Lists.newArrayList(Splitter.on(',').trimResults().omitEmptyStrings().split(propertyStr));
                properties = list.toArray(new String[list.size()]);
            }
}
//Other pieces of code
}

但是，PropertyRepository始终为null。我想Spring尚未初始化应用程序。我在这里想念什么吗？还是我应该遵循其他方式？我必须在此阶段加载属性，因为我有基于这些属性初始化的不同功能。