springboot无法从静态上下文中引用非静态变量的解决方法

@PropertySource(value = {"classpath:config/application.yml"},ignoreResourceNotFound = true,encoding="UTF-8") 
@Service 
public class tank_task {  
  private static String kafka;  
  public static String getProfilesKafka() { 
    return kafka; 
  }  
  @Value("${stream.kafka.servers}") 
  public void setProfilesKafka(String kafka) { 
    tank_task.kafka = kafka; 
  }  
  public static void tank_test(){  
    System.out.println("config static kafka :" + tank_task.getProfilesKafka()); 
  } 
}