Java list排序

list排序：（转载）
源：https://blog.youkuaiyun.com/heliangb46/article/details/77188939

java的实体bean结构

import java.util.ArrayList;
import java.util.List;

public class Human {
private String name;
private int age;

public Human() {
}

public Human(String name, int age) {
    this.name = name;
    this.age = age;
}

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;
}

@SuppressWarnings("serial")
public static List<Human> getAInitHumanList() {
    return new ArrayList<Human>() {
        {
            add(new Human("guorao", 10));
            add(new Human("mako", 12));
            add(new Human("hel", 30));
            add(new Human("lin", 28));
        }
    };
}

@Override
public String toString() {
    return this.getName() + ":" + this.getAge();
}

}

第一种：实现Comparator接口的类的对象作为sort的入参
public class HumanComparetor implements Comparator {
@Override
public int compare(Human h1, Human h2) {
if (h1.getAge() > h2.getAge()) {
return 1;
} else if (h1.getAge() == h2.getAge()) {
return 0;
} else {
return -1;
}
}
}
public static void main(String[] args) {
List humans = Human.getAInitHumanList();
Collections.sort(humans, new HumanComparetor());
System.out.println(humans);
}
第二种：在方法的局部使用局部类，原理和第一种差不多
public static void main(String[] args) {
List humans = Human.getAInitHumanList();
//方法内-局部类
class HumanComparetor implements Comparator {
@Override
public int compare(Human h1, Human h2) {
return h1.getAge() - h2.getAge();
}
}
Collections.sort(humans, new HumanComparetor());
System.out.println(humans);
}

第三种：基于第二种方法，局部类改为匿名类
public static void main(String[] args) {
List humans = Human.getAInitHumanList();
//匿名类
Collections.sort(humans, new Comparator() {
@Override
public int compare(Human h1, Human h2) {
return h1.getAge() - h2.getAge();
}
});
System.out.println(humans);
}

第四种：使用lamdba表达式->这种形式
public static void main(String[] args) {
List humans = Human.getAInitHumanList();
//lamdba 表达式 ->
Collections.sort(humans, (Human h1, Human h2) -> h1.getAge() - h2.getAge());
System.out.println(humans);
}
第五种：借助Comparator和lamdba表达式多条件排序
public static void main(String[] args) {
List humans = Human.getAInitHumanList();
lamdba 表达式 ::
Collections.sort(humans, Comparator.comparing(Human::getAge).thenComparing(Human::getName));
System.out.println(humans);
}
第六种：调用方式和第五种有区别，原理一样
public static void main(String[] args) {
List humans = Human.getAInitHumanList();
//直接用list.sort
humans.sort(Comparator.comparing(Human::getAge).thenComparing(Human::getName));
System.out.println(humans);
}