Java8一些特效2021-01-04

package com.cm.cmdc.module.web;

import java.time.LocalDate;

import java.time.LocalDateTime;

import java.time.LocalTime;

import java.time.ZonedDateTime;

import java.time.format.DateTimeFormatter;

import java.util.ArrayList;

import java.util.List;

public class Test {

public static void main(String[] args) {

List<Person> personList = creatPersonList();

personList.stream().filter(p -> p.getName().indexOf("菲") > 0).forEach(p -> System.out.println(p.getName()));

personList.stream().forEach(p -> System.out.println(p.toString()));

double hight =  personList.stream().filter(p -> p.getName().indexOf("菲") > 0).mapToDouble(p-> p.getHight()).average().getAsDouble();

System.out.println(hight);

    int i = personList.stream().mapToInt(p->p.getAge()).max().getAsInt();

    System.out.println("最大年龄" + i);

    LocalDate localDate = LocalDate.now();

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

    LocalDate.of(2020, 12, 12).getYear();

    localDate.getMonth();

    LocalTime localTime = LocalTime.now();

    localTime.getHour();

    localTime.getMinute();

    localTime.getSecond();

    LocalDateTime localDateTime = LocalDateTime.now();//上两个类的结合

    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

    LocalDateTime date = LocalDateTime.parse("2020-12-12 13:23:03", formatter);

    System.out.println(date.toString());

    ZonedDateTime zonedDateTime = ZonedDateTime.now();

    String strDate = zonedDateTime.format(formatter);

    System.out.println(strDate+"ddddddddddddd");

}

public static List<Person> creatPersonList() {

List<Person> personList = new ArrayList<Person>();

Person person = new Person("张飞", 33, Person.Sex.MAN, 1.77);

personList.add(person);

person = new Person("王菲", 32, Person.Sex.WOMAN, 1.51);

personList.add(person);

person = new Person("刘亦菲", 18, Person.Sex.WOMAN, 1.49);

personList.add(person);

person = new Person("韩非", 29, Person.Sex.MAN, 1.77);

personList.add(person);

return personList;

}

}
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package com.cm.cmdc.module.web;

public class Person {

public  static enum Sex{

MAN, WOMAN;

}

private String name;

private int  age;

private Sex gender;

private Double hight;

public Person() {

}

public Person(String name, int age, Sex gender, Double hight) {

super();

this.name = name;

this.age = age;

this.gender = gender;

this.hight = hight;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public Sex getGender() {

return gender;

}

public void setGender(Sex gender) {

this.gender = gender;

}

public Double getHight() {

return hight;

}

public void setHight(Double hight) {

this.hight = hight;

}

@Override

public String toString() {

return "Person [name=" + name + ", age=" + age + ", gender=" + gender + ", hight=" + hight + "]";

}

}