Java泛型接口实现

Question

我有一个如下界面,

public interface MethodExecutor {
    <T> List<T> execute(List<?> facts, Class<T> type) throws Exception;
}

另外,我有一个如下的通用实现,

public class DefaultMetodExecutor implements MethodExecutor {

   public <T> List<T> execute(List<?> facts, Class<T> type) throws Exception
   {
     List<T> result = null;

      //some implementation

      return result;
  }
}

至此,没有编译问题,

但是这个接口的具体实现无法编译,如下所示.

public class SpecificMetodExecutor implements MethodExecutor {

   public <Model1> List<Model1> execute(List<Model2> facts, Class<Model1> type) throws Exception
   {
     List<Model1> result = null;

     //some implementation specific to Model1 and Model2

      return result;
  } 
}

如何为某些已定义的对象实现此接口？我需要去上课级别的泛型吗？

Answer 1

您需要创建T类类型参数,而不是方法类型参数.您不能使用非泛型方法覆盖泛型方法.

public interface MethodExecutor<T> {
    List<T> execute(List<?> facts, Class<T> type) throws Exception;
}

public class DefaultMethodExecutor implements MethodExecutor<Model1> {
    public List<Model1> execute(List<?> facts, Class<Model1> type) throws Exception
    {
       //...
    }
} 

如果facts要为特定实现配置元素类型,则还需要将其作为参数.

public interface MethodExecutor<T, F> {
    List<T> execute(List<? extends F> facts, Class<T> type) throws Exception;
}