SpringBoot手動獲取Bean

此事起因是用多線程編寫定時任務，任務結束后有存儲數據庫的操作。我在線程的實現類里自動注入dao類，結果執行save操作報注入類實例空指針異常。

Exception in thread "bd213f61a79f4436bf8f0bcd668a8e07" java.lang.NullPointerException: Cannot invoke "com.lhx.upgrade.repositories.UpgradeRecordRepository.save(Object)" because "this.recordRepository" is null

看來Spring是不會給線程自動注入。

找到一種手工從bean工廠獲取依賴的辦法：

@Component
public class BeanFactory implements ApplicationContextAware {
    private static ApplicationContext applicationContext = null;

    @Override
    public void setApplicationContext(ApplicationContext arg0) throws BeansException {
        // TODO Auto-generated method stub
        BeanFactory.applicationContext = arg0;
    }
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    public static <T> T getBean(Class<T> clazz) {
        return getApplicationContext().getBean(clazz);
    }
}

在線程的run函數里添加下面代碼即可

UpgradeRecordRepository recordRepository = BeanFactory.getBean(UpgradeRecordRepository.class);
recordRepository.save(record);