package com.wangms;

import java.time.Duration;

import java.time.LocalDate;

import java.time.LocalDateTime;

import java.time.Period;

import java.time.temporal.ChronoUnit;

import java.util.*;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import static java.util.stream.Collectors.toCollection;

/**

* @author: wangms

* @date: 2020-08-28 14:36

*/

public class Lambda {

public static void main(String[] args) {

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

map.put("1", "张三");

map.put("2", "李四");

map.put("3", "王五");

Collection<String> s1 = map.values();

System.out.println(s1);

for (String s : map.keySet()) {

System.out.println(s);

}

map.forEach((a, b) -> {

System.out.println(b);

});

List<String> list = new ArrayList<String>();

list.add("a");

list.add("b");

list.add("c");

list.forEach(v -> {

System.out.println(v);

});

String str = list.stream().findFirst().toString();

System.out.println(str);

Runnable runnable = new Runnable() {

@Override

public void run() {

System.out.println("1");

}

};

Runnable runnable1 = () -> System.out.println("1");

Stream stream = Stream.of("a", "b", "c");

System.out.println("limit:");

stream.limit(2).forEach(System.out::println);

List<Integer> list11 = new ArrayList<Integer>();

list11.add(4);

list11.add(3);

list11.add(2);

list11.add(3);

list11.stream().sorted(Comparator.reverseOrder()).forEach(System.out::println);

long count = list11.parallelStream().filter(a -> a == 3).count();

System.out.println("count:"+count);

list11.stream().distinct().forEach(a-> System.out.println("aa:"+a));

List<Integer> numbers = Arrays.asList(1, 5, 7, 3, 9);

IntSummaryStatistics stats = numbers.stream().mapToInt((x) -> x).summaryStatistics();

System.out.println("列表中最大的数 : " + stats.getMax());

System.out.println("列表中最小的数 : " + stats.getMin());

System.out.println("所有数之和 : " + stats.getSum());

System.out.println("平均数 : " + stats.getAverage());

System.out.println(LocalDate.now());

System.out.println(LocalDateTime.now());

System.out.println(new Date());

LocalDateTime ld = LocalDateTime.parse("2020-09-01T11:11:30.222Z");

LocalDateTime ld2 = LocalDateTime.parse("2020-09-01T11:11:30.111Z");

System.out.println("相差毫秒 : " + Duration.between(ld, ld2).toMillis());

System.out.println("相毫秒 : " + Duration.between(ld, ld2).getSeconds());

String[] strArray = new String[] { "a", "b", "c" };

stream = Stream.of(strArray);

stream = Arrays.stream(strArray);

//List<String> list = Arrays.asList(strArray);

// stream = list.stream();

try {

Stream<String> stream2 = Stream.of("a", "b", "c");

// 转换成 Array

String[] strArray1 = stream2.toArray(String[]::new);

// 转换成 Collection

List<String> list1 = stream2.collect(Collectors.toList());

List<String> list2 = stream2.collect(toCollection(ArrayList::new));

Set set1 = stream2.collect(Collectors.toSet());

Stack stack1 = stream2.collect(toCollection(Stack::new));

// 转换成 String

// String str = stream.collect(Collectors.joining()).toString();

} catch (Exception e) {

e.printStackTrace();

}

}

}