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> {

   MyGenericClass<T> generic;

   public MyGenericClass (MyGenericClass<T> generic){

       this.generic = generic;

   }

}