为什么要实现 Comparator<t> 而不是简单的 Comparator

Question

class problemsolver implements Comparator<Student> {

   public int compare(Student obj1,Student obj2) {
       return obj1.fname.compareTo(obj2.fname);
   } 
}

当我简单地写 class problemsolver implements Comparator 时，它显示了这个错误。

prog.java:25: error: problemsolver is not abstract and does not override abstract method compare(Object,Object) in Comparator

为什么？

Answer 1

隐式 Comparator 是 Comparator<Object>，然后编译器希望您实现 compare(Object, Object).

您需要的是：

class problemsolver implements Comparator<Student>

为什么要实现 Comparator<t> 而不是简单的 Comparator

why to implements Comparator<t> not simply Comparator

java

comparator