About the problem that @Autowired is NULL in the use of @Component in Java

1.  The code that found the above problem is as follows: Direct use of @Autowired in @Component causes the code to report a null pointer
    

   @Component
   public class ThreasTestDemo extends Thread {
       private String personalId;
       private HttpSession httpSession;
       @Autowired
       private McPersonalInfoService mcPersonalInfoService;
   }

2. The processing code is as follows:
    

   
   @Component
   public class ThreasTestDemo extends Thread{
       private String personalId;
       private HttpSession httpSession;
   
       private static McPersonalInfoService mcPersonalInfoService;
   
       @Autowired
       public void setMcPersonalInfoService (McPersonalInfoService mcPersonalInfoService){
           ThreasTestDemo.mcPersonalInfoService= mcPersonalInfoService;
       }
   }

   3. The reason is roughly as follows:
             When using the @Componet annotation to instantiate a bean into the Spring container, @Autowired is in the bean, and @Autowired has not completed the automatic loading, so the service is null