@Autowired静态注入导致的sonar坏味道：Write to static field ...Utils.staticService from instance method ...Utils.init()

sonar扫描出现了一个严重的坏味道Write to static field ...Utils.staticService from instance method ...Utils.init()

 

意思就是：当一个静态变量直接赋值给静态变量，在多线程调用的情况下，容易出现问题。

 

解决方法就是使用两个set方法（一个静态set方法，一个动态set方法），代替动态变量直接赋值给静态变量的写法。

 

修改前的代码：

@Component
public class RuleDocTypeUtils {

     private static final Logger LOGGER =  LoggerFactory.getLogger(RuleDocTypeUtils.class);
     
     private static DocTypeRuleServiceImpl staticService = new  DocTypeRuleServiceImpl();
    
     @Autowired
     private DocTypeRuleServiceImpl dynamicService;
     
     @PostConstruct
     public void init() {
           staticService = dynamicService;
     }

     ...

}

可以看到，在init()方法中动态服务对象直接赋值给静态服务对象，正是这一行出了问题，如果改为使用set注入静态服务对象的方式，一样有这个问题

修改后的代码：

@Component
public class RuleDocTypeUtils {

     private static final Logger LOGGER =  LoggerFactory.getLogger(RuleDocTypeUtils.class);
     
     private static DocTypeRuleServiceImpl staticService = new  DocTypeRuleServiceImpl();
    
     @Autowired
     private DocTypeRuleServiceImpl dynamicService;
     
     @PostConstruct
     public void init() {
           setService(dynamicService);
     }

     private void setService(DocTypeRuleServiceImpl  dynamicService) {
           setStaticService(dynamicService);
     }

     private synchronized static void  setStaticService(DocTypeRuleServiceImpl dynamicService) {
           RuleDocTypeUtils.staticService = dynamicService;
     }

     ...

}

参考：

    1.Write to static field from instance method ：  https://stackoverflow.com/questions/24703755/write-to-static-field-from-instance-method?r=SearchResults

    2.FindBugs error: Write to static field from instance method ：  https://stackoverflow.com/questions/21136302/findbugs-error-write-to-static-field-from-instance-method#

    3.FindBugs error: Write to static field from instance method ：  http://www.hackerav.com/?post=61820