如何解決模棱兩可的方法參考？

Question

如何解決類Test中的兩條錯誤行，而無需修改類Case？

class Case { 
    public boolean isEmpty() { 
     return true; 
    } 

    public static boolean isEmpty(Case t) { 
     return true; 
    } 
} 

public class Test { 
    public static void main(String[] args) { 
     Predicate<Case> forNonStaticMethod = Case::isEmpty;//<--TODO: fix compile error: 
     Predicate<Case> forStaticMethod = Case::isEmpty;//<--TODO: fix compile error: 
     //Ambiguous method reference: both isEmpty() and isEmpty(Case) from the type Case are eligible   
    } 
} 

Answer 1

您可以使用lambda表達式而不是方法的引用：

Predicate<Case> forNonStaticMethod = c -> c.isEmpty(); 
Predicate<Case> forStaticMethod = c -> Case.isEmpty(c);