关于lambda表达式一些用法

直接给个例子吧，复制过去就能运行看效果的

package com.rogrand.highsunproperty.test.lambda;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import java.util.function.Consumer;
import java.util.function.Predicate;

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

public class Person {
private String firstName, lastName, job, gender;

private int salary, age;

public Person(String firstName, String lastName, String job,
String gender, int age, int salary) {
this.firstName = firstName;
this.lastName = lastName;
this.gender = gender;
this.age = age;
this.job = job;
this.salary = salary;
}

public String getFirstName() {
return firstName;
}

public void setFirstName(String firstName) {
this.firstName = firstName;
}

public String getLastName() {
return lastName;
}

public void setLastName(String lastName) {
this.lastName = lastName;
}

public String getJob() {
return job;
}

public void setJob(String job) {
this.job = job;
}

public String getGender() {
return gender;
}

public void setGender(String gender) {
this.gender = gender;
}

public int getSalary() {
return salary;
}

public void setSalary(int salary) {
this.salary = salary;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

public static void main(String[] args) {
List<Person> javaProgrammers = getJavaPersons();
List<Person> phpProgrammers = getPhpPersons();
System.out.println("*********所有程序员的姓名****:");
javaProgrammers.forEach(p -> System.out.printf("%s %s; ", p.getFirstName(), p.getLastName()));
phpProgrammers.forEach(p -> System.out.printf("%s %s; ", p.getFirstName(), p.getLastName()));

System.out.println("给程序员加薪 5% :");
Consumer<Person> giveRaise = e -> e.setSalary(e.getSalary() / 100 * 5 + e.getSalary());
javaProgrammers.forEach(giveRaise);
phpProgrammers.forEach(giveRaise);

System.out.println("下面是月薪超过 $1,400 的PHP程序员:");
phpProgrammers.stream()
.filter((p) -> (p.getSalary() > 1400))
.forEach((p) -> System.out.printf("%s %s; ", p.getFirstName(), p.getLastName()));

// 定义 filters
Predicate<Person> ageFilter = (p) -> (p.getAge() > 25);
Predicate<Person> salaryFilter = (p) -> (p.getSalary() > 1400);
Predicate<Person> genderFilter = (p) -> ("female".equals(p.getGender()));

System.out.println("下面是年龄大于 24岁且月薪在$1,400以上的女PHP程序员:");
phpProgrammers.stream()
.filter(ageFilter)
.filter(salaryFilter)
.filter(genderFilter)
.forEach((p) -> System.out.printf("%s %s; ", p.getFirstName(), p.getLastName()));

System.out.println("最前面的3个女性 Java programmers:");
javaProgrammers.stream().filter(genderFilter).limit(3).forEach((p) -> System.out.printf("%s %s; ", p.getFirstName(), p.getLastName()));

System.out.println("根据 name 排序,并显示前5个 Java programmers:");
List<Person> sortedJavaProgrammers = javaProgrammers.stream().sorted((p, p2) -> (p.getFirstName().compareTo(p2.getFirstName())))
.limit(5).collect(toList());
sortedJavaProgrammers.forEach((p) -> System.out.printf("%s %s; %n", p.getFirstName(), p.getLastName()));

System.out.println("获取java程序员所有的年龄（去掉重复的）:");
Set<Integer> collect = javaProgrammers.stream().map(Person::getAge).collect(toSet());//降年龄装换成set集合,如果不需要去重可以使用List
collect.stream().sorted().forEach(info -> System.out.printf("%s; ", info));//升序
collect.stream().sorted((p, p2) -> (p2 - p)).forEach(info -> System.out.printf("%s; ", info));//降序

System.out.println("工资最低的 Java programmer:");
Person pers = javaProgrammers.stream().min((p1, p2) -> (p1.getSalary() - p2.getSalary())).get();
System.out.printf("Name: %s %s; Salary: $%,d.", pers.getFirstName(), pers.getLastName(), pers.getSalary());
System.out.println();
System.out.println("工资最高的 Java programmer:");
Person person = javaProgrammers.stream().max((p, p2) -> (p.getSalary() - p2.getSalary())).get();
System.out.printf("Name: %s %s; Salary: $%,d.", person.getFirstName(), person.getLastName(), person.getSalary());
System.out.println();
System.out.print("将 PHP programmers 的 first name 拼接成字符串:");
String phpDevelopers = phpProgrammers.stream().map(Person::getFirstName).collect(joining(" ; ")); // 在进一步的操作中可以作为标记(token)
System.out.println(phpDevelopers);

System.out.print("将 Java programmers 的 first name 存放到 Set:");
Set<String> javaDevFirstName = javaProgrammers.stream().map(Person::getFirstName).collect(toSet());
javaDevFirstName.forEach(s -> System.out.println(s));
System.out.println("将 Java programmers 的 first name 存放到 TreeSet:");
TreeSet<String> javaDevLastName = javaProgrammers.stream().map(Person::getLastName).collect(toCollection(TreeSet::new));
javaDevLastName.forEach(s -> System.out.println(s));
}

private static List<Person> getPhpPersons() {
List<Person> phpProgrammers = new ArrayList<>();
phpProgrammers.add(new Person("Jarrod", "Pace", "PHP programmer", "male", 34, 1550));
phpProgrammers.add(new Person("Clarette", "Cicely", "PHP programmer", "female", 23, 1200));
phpProgrammers.add(new Person("Victor", "Channing", "PHP programmer", "male", 32, 1600));
phpProgrammers.add(new Person("Tori", "Sheryl", "PHP programmer", "female", 21, 1000));
phpProgrammers.add(new Person("Osborne", "Shad", "PHP programmer", "male", 32, 1100));
phpProgrammers.add(new Person("Rosalind", "Layla", "PHP programmer", "female", 25, 1300));
phpProgrammers.add(new Person("Fraser", "Hewie", "PHP programmer", "male", 36, 1100));
phpProgrammers.add(new Person("Quinn", "Tamara", "PHP programmer", "female", 21, 1000));
phpProgrammers.add(new Person("Alvin", "Lance", "PHP programmer", "male", 38, 1600));
phpProgrammers.add(new Person("Evonne", "Shari", "PHP programmer", "female", 40, 1800));
return phpProgrammers;
}

private static List<Person> getJavaPersons() {
List<Person> javaProgrammers = new ArrayList<>();
javaProgrammers.add(new Person("Elsdon", "Jaycob", "Java programmer", "male", 23, 2000));
javaProgrammers.add(new Person("Tamsen", "Brittany", "Java programmer", "female", 23, 1500));
javaProgrammers.add(new Person("Floyd", "Donny", "Java programmer", "male", 23, 1800));
javaProgrammers.add(new Person("Sindy", "Jonie", "Java programmer", "female", 32, 1600));
javaProgrammers.add(new Person("Vere", "Hervey", "Java programmer", "male", 22, 1200));
javaProgrammers.add(new Person("Maude", "Jaimie", "Java programmer", "female", 27, 1900));
javaProgrammers.add(new Person("Shawn", "Randall", "Java programmer", "male", 30, 2300));
javaProgrammers.add(new Person("Jayden", "Corrina", "Java programmer", "female", 35, 1700));
javaProgrammers.add(new Person("Palmer", "Dene", "Java programmer", "male", 33, 2000));
javaProgrammers.add(new Person("Addison", "Pam", "Java programmer", "female", 34, 1300));
return javaProgrammers;
}
}