我有通用類：public class MyGenericClass<T> {   T get(){     return T;    }   ...}有2個類：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;   }}我認為最好創建public abstact class Service：public abstract class Service {   MyGenericClass generic;   public MyGenericClass (MyGenericClass generic){   this.generic = generic;   }}并使CatService和DogService 擴展這個抽象服務。他們將在調用super(MyGenericClass generic)或super(MyGenericClass generic)的構造函數中初始化泛型字段。但是在這種情況下，當我嘗試調用 MyGenericClass 方法時，我收到“unchecked call”，當我嘗試調用 T get() 時，我必須使用(Cat) generic.get() OR (Dog) generic.get()；有可能避免嗎？更新：需要指定泛型類型：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;   }}