Stream

package com.redisson;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.function.Supplier;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * @Description TODO
 * @Date 2020/7/28 9:09
 * @Author zsj
 */
public class StreamTest {
    public static void main(String[] args) throws Exception {
        List personList = new ArrayList();
        Person p1 = new Person();
        p1.setAge(10);
        p1.setName("zlx");
        personList.add(p1);
        p1 = new Person();
        p1.setAge(12);
        p1.setName("jiaduo");
        personList.add(p1);
        p1 = new Person();
        p1.setAge(5);
        p1.setName("ruoran");
        personList.add(p1);
        p1 = new Person();
        p1.setAge(5);
        p1.setName("rxxx");
        personList.add(p1);

        p1 = new Person();
        p1.setAge(10);
        p1.setName("iii");
        personList.add(p1);

        p1 = new Person();
        p1.setAge(22);
        p1.setName("iiizz");
        personList.add(p1);



//根据age对list分组
        Map> groupByAge = personList.parallelStream().collect(Collectors.groupingBy(Person::getAge));
//根据age进行排序（reserve倒序）

        List peopleListSorted = personList.parallelStream().sorted(Comparator.comparing(Person::getAge).reversed()).collect(Collectors.toList());


//提取age,并排序
        List ageList = personList.stream().map(Person::getAge).distinct().sorted().collect(Collectors.toList());

        //提取年龄大于20的people
        List olderThan20 = personList.parallelStream().filter(e->e.getAge() > 20).collect(Collectors.toList());

        String str = Stream.of("A", "B", "C", "D").reduce("-", String::concat);
        String str2 = Stream.of("A", "B", "C", "D").collect(Collectors.joining("-"));

        int sum = Stream.of(1, 2, 3, 4).reduce(Integer::sum).get();
        int sum2 = Stream.of(1, 2, 3, 4).reduce(7, Integer::sum);

        List names = personList.parallelStream().filter(person -> person.getAge() > 9)
                .map(person -> person.getName()).collect(Collectors.toList());
        names.forEach(ii -> {
            System.out.println(ii);
        });

    }


}