java - 访问服务组件中的静态变量的好方法

Question

 public interface ABCHelper { 
      ...
      ...
    }

    @Service(ABCHelper.class)
    @Component(immediate = true, metatype = true)
    public class ABCHelperImpl implements ABCHelper {
      private static String DEMO = "demo";
      ...
      ...
    }


@Service(XYZ.class)
    @Component(immediate = true, metatype = true)
    public class XYZHelperImpl implements XYZHelper {
      @Reference private ABCHelper abcHelper;
      ...
      ...
    }

现在要获取 XYZHelper 中 DEMO 变量的值，以下哪种方法比较好:

方法1:将DEMO变量设置为公共(public)变量，然后按如下方式访问它:

@Service(XYZ.class)
        @Component(immediate = true, metatype = true)
        public class XYZHelperImpl implements XYZHelper {
          @Reference private ABCHelper abcHelper;
          ...
          ...
          void f() {
           String s = ABCHelperImpl.DEMO ;
          }
    }

方法2:在ABCHelperImpl中定义静态方法，然后按如下方式处理它:

@Service(ABCHelper.class)
    @Component(immediate = true, metatype = true)
    public class ABCHelperImpl implements ABCHelper {
      private static String DEMO = "demo";
      ...
      ...
  public static String getDemo() {
     return DEMO; 
   }
 }

@Service(XYZ.class)
    @Component(immediate = true, metatype = true)
    public class XYZHelperImpl implements XYZHelper {
      @Reference private ABCHelper abcHelper;
      ...
      ...
      void f() {
       String s = ABCHelperImpl.getDemo() ;
      }
}

方法 3:

public interface ABCHelper { 
      ...
      ...
      public String getDemo();
    }

    @Service(ABCHelper.class)
    @Component(immediate = true, metatype = true)
    public class ABCHelperImpl implements ABCHelper {
      private static String DEMO = "demo";
      ...
      ...
  public static String getDemo() {
     return DEMO; 
   }
 }

@Service(XYZ.class)
    @Component(immediate = true, metatype = true)
    public class XYZHelperImpl implements XYZHelper {
      @Reference private ABCHelper abcHelper;
      ...
      ...
      void f() {
       String s = abcHelper.getDemo() ;
      }
}

Answer 1

我认为最好的方法是将这个变量移动到某个Constants类公开并在您需要的任何地方使用它。