code: protected AbstractApplicationContext resolveByXml(Component component,
                                                        ApplicationContext parent) {
          XmlComponentApplicationContext context = new XmlComponentApplicationContext(component, parent);
          try {
              Resource resource = component.getResourceLoader().getResource(APP_XML);
              context.load(resource);
          } catch (Exception e) {
              throw new ApplicationConfigurationException("Can't load context from application stream", e);
          }
          return context;
      }
docs: XML方式解析独立的应用程序包
  
  @param component 组件对象
  @return 加载出来的应用程序上下文