Java 中的泛型 - 使用抽象类进行类型擦除

Question

我有通用类：

public class MyGenericClass<T> {

   T get(){

     return T;

    }

   ...

}

有2个类：

public class CatService{

   MyGenericClass<Cat> generic;

   public CatService(MyGenericClass<Cat> generic){

   this.generic = generic;

   }

}

public class DogService{

   MyGenericClass<Dog> generic;

   public DogService(MyGenericClass<Dog> generic){

   this.generic = generic;

   }

}

我认为最好创建public abstact class Service：

public abstract class Service {

   MyGenericClass generic;

   public MyGenericClass (MyGenericClass generic){

   this.generic = generic;

   }

}

并使CatService和DogService 扩展这个抽象服务。他们将在调用super(MyGenericClass generic)或super(MyGenericClass generic)的构造函数中初始化泛型字段。

但是在这种情况下，当我尝试调用 MyGenericClass 方法时，我收到“unchecked call”，当我尝试调用 T get() 时，我必须使用(Cat) generic.get() OR (Dog) generic.get()；

有可能避免吗？

更新：需要指定泛型类型：extends Service<Cat>

public class CatService extends Service<Cat> {

   public CatService(MyGenericClass<Cat> generic){

   super(generic);

   }

}

public abstract class Service<T> {

   MyGenericClass<T> generic;

   public MyGenericClass (MyGenericClass<T> generic){

   this.generic = generic;

   }

}

Answer 1

使Service类也通用。public abstract class Service<T> {&nbsp; &nbsp;MyGenericClass<T> generic;&nbsp; &nbsp;public MyGenericClass (MyGenericClass<T> generic){&nbsp; &nbsp; &nbsp; &nbsp;this.generic = generic;&nbsp; &nbsp;}}