springboot在listener和filter中注入mapper会为null

柔情只为你懂 2022-12-29 12:49 144阅读 0赞

> `因为监听器和过滤器加载顺序会优先于spring容器初始化实例，所以我们需要手动获取Bean`

@Component
    public class SpringContextUtil implements ApplicationContextAware { 
    
        private static ApplicationContext applicationContext;
    
        @Override
        public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { 
            SpringContextUtil.applicationContext = applicationContext;
        }
    
        //获取applicationContext
        public static ApplicationContext getApplicationContext() { 
            return applicationContext;
        }
    
        //通过name获取 Bean.
        public static Object getBean(String name) { 
            return getApplicationContext().getBean(name);
        }
    
        //通过class获取Bean.
        public static <T> T getBean(Class<T> clazz) { 
            return getApplicationContext().getBean(clazz);
        }
    
        //通过name,以及Clazz返回指定的Bean
        public static <T> T getBean(String name, Class<T> clazz) { 
            return getApplicationContext().getBean(name, clazz);
        }
    
    }

> `然后在实现的方法中使用手动获取的Bean即可`

@Override
        public void invoke(ReadExcelExpress readExcelExpress, AnalysisContext analysisContext) { 
            SparesRequirementMapper sparesRequirementMapper = SpringContextUtil.getBean(SparesRequirementMapper.class);
            ExpressMapper expressMapper = SpringContextUtil.getBean(ExpressMapper.class);
            //然后使用mapper操作数据库即可
        }

> `ok`