解决SpringMvc中普通类注入Service为null的问题
作者:猫猫桑
这篇文章主要介绍了解决SpringMvc中普通类注入Service为null的问题,具有很好的参考价值,希望对大家有所帮助。如有错误或未考虑完全的地方,望不吝赐教
SpringMvc中普通类注入Service为null
场景:
使用Quartz定时器时,普通的java类需要注入spring的service类,在调用时报错!
解决方式:
/** * 定时获取课程的service */ @Autowired protected QuartzGetCourseService quartzGetCourseService = (QuartzGetCourseService) SpringContextUtil .getBean("quartzGetCourseService");
import org.springframework.beans.BeansException; import org.springframework.beans.factory.NoSuchBeanDefinitionException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.stereotype.Component; /** * 在Spring 注解中,普通类获取@Service标记的方法或者bean对象 * */ @Component public class SpringContextUtil implements ApplicationContextAware { private static ApplicationContext applicationContext = null; @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { SpringContextUtil.applicationContext = applicationContext; } public static ApplicationContext getApplicationContext() { return applicationContext; } /** * 注意 bean name默认 = 类名(首字母小写) 例如: A8sClusterDao = getBean("a8sClusterDao") * * @param name * @return * @throws BeansException */ public static Object getBean(String name) throws BeansException { return applicationContext.getBean(name); } /** * 根据类名获取到bean * * @param <T> * @param clazz * @return * @throws BeansException */ @SuppressWarnings("unchecked") public static <T> T getBeanByName(Class<T> clazz) throws BeansException { try { char[] cs = clazz.getSimpleName().toCharArray(); cs[0] += 32;// 首字母大写到小写 return (T) applicationContext.getBean(String.valueOf(cs)); } catch (Exception e) { e.printStackTrace(); return null; } } public static boolean containsBean(String name) { return applicationContext.containsBean(name); } public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException { return applicationContext.isSingleton(name); } }
调用结束,测试可以获取Service.
spring之工具类使用service注入
一般需要在一个工具类中使用@Autowired 注解注入一个service。但是由于工具类方法一般都写成static,所以直接注入就存在问题。
栗子:
@Component public class SmsController { private static Logger logger = LoggerFactory.getLogger(SmsController.class); @Autowired private MessagesInfoService messagesInfoService; private static SmsController smsController; @PostConstruct public void init() { smsController = this; smsController.messagesInfoService = this.messagesInfoService; } /** *短信历史查询接口(查询某个时间段发送的短信) */ @RequestMapping(value = "/queryMessage",method = RequestMethod.GET) public ModelAndView queryMessage{ pager = messagesInfoService.findPager(map,5,pIndex); ModelAndView modelAndView = new ModelAndView("manage/jgdxgl/jgdx_qm"); List<MessagesInfo> list = pager.getItem(); modelAndView.addObject("pager",pager); modelAndView.addObject("list",list); return modelAndView } }
以上为个人经验,希望能给大家一个参考,也希望大家多多支持脚本之家。