Java工具类中注入springBean NullPointException

@Component
public class DDDUtils {
    
    

  private static CodeService codeService;

  @Autowired
  public DDDUtils(CodeService codeService) {
    
    
    DDDUtils.codeService= codeService;
  }
  //这样就可以解决这个问题了
  public static String createCode(String code) {
    
    
  	return codeService.createCode(code);
  }
}

记录一下，不然每次用到都要找找找，哈哈