java的實體bean結構
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();
}
}
第一種:實現Comparator接口的類的對象作爲sort的入參
public class HumanComparetor implements Comparator<Human> {
@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<Human> humans = Human.getAInitHumanList();
Collections.sort(humans, new HumanComparetor());
System.out.println(humans);
}
第二種:在方法的局部使用局部類,原理和第一種差不多
public static void main(String[] args) {
List<Human> humans = Human.getAInitHumanList();
//方法內-局部類
class HumanComparetor implements Comparator<Human> {
@Override
public int compare(Human h1, Human h2) {
return h1.getAge() - h2.getAge();
}
}
Collections.sort(humans, new HumanComparetor());
System.out.println(humans);
}
第三種:基於第二種方法,局部類改爲匿名類
public static void main(String[] args) {
List<Human> humans = Human.getAInitHumanList();
//匿名類
Collections.sort(humans, new Comparator<Human>() {
@Override
public int compare(Human h1, Human h2) {
return h1.getAge() - h2.getAge();
}
});
System.out.println(humans);
}
第四種:使用lamdba表達式->這種形式
public static void main(String[] args) {
List<Human> humans = Human.getAInitHumanList();
//lamdba 表達式 ->
Collections.sort(humans, (Human h1, Human h2) -> h1.getAge() - h2.getAge());
System.out.println(humans);
}
第五種:藉助Comparator和lamdba表達式多條件排序
public static void main(String[] args) {
List<Human> humans = Human.getAInitHumanList();
////lamdba 表達式 ::
Collections.sort(humans, Comparator.comparing(Human::getAge).thenComparing(Human::getName));
System.out.println(humans);
}
第六種:調用方式和第五種有區別,原理一樣
public static void main(String[] args) {
List<Human> humans = Human.getAInitHumanList();
//直接用list.sort
humans.sort(Comparator.comparing(Human::getAge).thenComparing(Human::getName));
System.out.println(humans);
}
原文:https://blog.csdn.net/heliangb46/article/details/77188939