Java新特性解读JDK8之流操作max和min函数

/**
*Returns the maximum element of this stream according to the provided
*即返回最大元素
*/
Optional<T> max(Comparator<? super T> comparator);


/**
* Comparator是一个函数式接口
*/
@FunctionalInterface
public interface Comparator<T> {
    int compare(T o1, T o2);
}

package com.example.streamdemo;


import java.util.Arrays;
import java.util.List;
import java.util.Optional;


public class MaxDemo {
  public static void main(String[] args) {
    List<Integer> list = Arrays.asList(1,2,3);
    Optional<Integer> optional = list.stream().max((a,b)->Integer.compare(a, b));
    System.out.println("max: "+optional.get());
    Optional<Integer> optional2 = list.stream().min((a,b)->Integer.compare(a, b));
    System.out.println("min: "+optional2.get());
  }
}