stream其他操作

package com.ydlclass.feature;

import org.junit.Before;
import org.junit.Test;

import java.util.*;
import java.util.function.*;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.stream.Stream;

public class LambdaTest {
    List<Person> personList = new ArrayList<>();
    List<Integer> simpleList = Arrays.asList(15,22,9,11,33,52,14);
    @Before
    public void initData(){
        personList.add(new Person("张三",3000,23,"男","太原"));
        personList.add(new Person("李四",7000,34,"男","西安"));
        personList.add(new Person("王五",5200,22,"女","西安"));
        personList.add(new Person("小黑",1500,33,"女","上海"));
        personList.add(new Person("狗子",8000,44,"女","北京"));
        personList.add(new Person("铁蛋",6200,36,"女","南京"));
    }

    @Test
    public void otherTest(){
        personList.stream().sorted((o1, o2) -> o2.getSalary() - o1.getSalary()).
                limit(3).forEach(System.out::println);

        //首先去除了重复，跳过之后使用
        List<Integer> list = Arrays.asList(1, 2, 3, 4, 4, 5, 1);
        list.stream().distinct().skip(2).forEach(System.out::println);

        //找出男员工和女员工中工资最高的人

        Map<String, List<Person>> collect = personList.stream().collect(Collectors.groupingBy(new Function<Person, String>() {
            @Override
            public String apply(Person person) {
                return person.getSex();
            }
        }));
        collect.get("女").stream().sorted((o1, o2) -> o2.getSalary() - o1.getSalary()).limit(1).forEach(System.out::println);
        collect.get("男").stream().sorted((o1, o2) -> o2.getSalary() - o1.getSalary()).limit(1).forEach(System.out::println);

        //方式二
        Map<String, List<Person>> collect1 = personList.stream().collect(Collectors.groupingBy(person -> person.getSex()));

        Map<String,Integer> map = new HashMap<>(2);

        for (Map.Entry<String, List<Person>> stringListEntry : collect1.entrySet()) {
            String key = stringListEntry.getKey();
            IntStream intStream = stringListEntry.getValue().stream().mapToInt(new ToIntFunction<Person>() {
                @Override
                public int applyAsInt(Person value) {
                    return value.getSalary();
                }
            });
            int value = intStream.max().orElse(0);
            map.put(key,value);
        }
        System.out.println(map);
    }


}