canna-cloud【四】spring boot的bean延迟初始化

逻辑：

1、定义初始化抽象接口InitService

2、通过监听器，在启动完成后，遍历所有的bean，判断是否实现了接口InitService。

3、如果实现了接口，则调用接口中的初始化方法，并根据接口定义的初始化顺序先后进行初始化。

public interface InitService {

	/*
     *  order 越大 约先初始化
	 */
    /**
     * 拦截器
     */
    static final Integer INTERCEPT_ORDER = 1000;    //  >= 1000
    /**
     * 队列
     */
    static final Integer QUEUE_ORDER = 2000;        // >= 2000
    /**
     * 控制器
     */
    static final Integer CONTROLLER_ORDER = 3000;   // >= 3000
    /**
     * 定时任务
     */
    static final Integer SCHEDULE_ORDER = 4000;   // >= 4000
    /**
     * service服务
     */
    static final Integer SERVICE_ORDER = 5000;        // >= 5000
    /**
     * 配置实例化
     */
    static final Integer CONFIGURE_ORDER = 6000;   // >= 6000

    int getOrder();

    void init() throws CannaException;

}

public class EndStartedListener implements ApplicationListener<ContextRefreshedEvent> {

    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {

        if (((ApplicationContextEvent) event).getApplicationContext().getParent() == null) {
            try {
                this.initSystem(SpringContextHolder.getApplicationContext());
            } catch (CannaException e) {
                log.error("", e);
            }
        }

    }

    public void initSystem(ApplicationContext context) throws CannaException {
        String beans[] = context.getBeanDefinitionNames();

        log.info("bean length:{}", beans.length);
        Map<Integer, List<Object>> beanMap = new HashMap<Integer, List<Object>>();
        for (String bean : beans) {
            Object obj = context.getBean(bean);

            if (obj instanceof InitService) {
                InitService initService = (InitService) obj;

                Integer key = initService.getOrder();
                List<Object> beanList = beanMap.get(key);
                if (beanList == null) {
                    beanList = new ArrayList<Object>();
                    beanMap.put(key, beanList);
                }
                beanList.add(initService);
            }
        }
        if (beanMap.isEmpty()) {
            return;
        }
        Set<Integer> keySet = beanMap.keySet();
        Integer[] keyArr = keySet.toArray(new Integer[]{});
        Arrays.sort(keyArr);
        for (int i = keyArr.length - 1; i >= 0; i--) {
            Integer IKey = keyArr[i];
            List<Object> beanList = beanMap.get(IKey);
            for (Object obj : beanList) {
                if (obj instanceof InitService) {
                    InitService initService = (InitService) obj;
                    initService.init();
                }
            }
        }

    }

}