时间:2021-01-13 09:50:36 | 栏目:JAVA代码 | 点击:次
这篇文章主要介绍了Java8 Comparator排序方法实例详解,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
Java8 中 Comparator 接口提供了一些静态方法,可以方便于我们进行排序操作,下面通过例子讲解下如何使用
对整数列表排序(升序)
List<Integer> list = Arrays.asList(1, 4, 2, 6, 2, 8); list.sort(Comparator.naturalOrder()); System.out.println(list);
对整数列表排序(降序)
List<Integer> list = Arrays.asList(1, 4, 2, 6, 2, 8); list.sort(Comparator.reverseOrder()); System.out.println(list);
根据对象属性(年龄)进行排序
public class Test { public static void main(String[] args) { List<Person> personList = new ArrayList<>(); personList.add(new Person("a", 2)); personList.add(new Person("b", 4)); personList.add(new Person("c", 7)); // 升序 personList.sort(Comparator.comparingInt(Person::getAge)); // 降序 personList.sort(Comparator.comparingInt(Person::getAge).reversed()); System.out.println(personList); } public static class Person { private String name; private Integer age; public Person(String name, Integer age) { this.name = name; this.age = age; } public Integer getAge() { return age; } // ... toString 方法 } }
根据对象属性(价格、速度)进行排序,需要注意的是,排序有先后之分,不同的顺序会导致不同的结果
public class Test { public static void main(String[] args) { List<Computer> list = new ArrayList<>(); list.add(new Computer("xiaomi",4000,6)); list.add(new Computer("sony",5000,4)); list.add(new Computer("dell",4000,5)); list.add(new Computer("mac",6000,8)); list.add(new Computer("micro",5000,6)); // 先以价格(升序)、后再速度(升序) list.sort(Comparator.comparingInt(Computer::getPrice).thenComparingInt(Computer::getSpeed)); // 先以速度(降序)、后再价格(升序) list.sort(Comparator.comparingInt(Computer::getSpeed).reversed().thenComparingInt(Computer::getPrice)); // 先以价格(降序)、后再速度(降序) list.sort(Comparator.comparingInt(Computer::getPrice).thenComparingInt(Computer::getSpeed).reversed()); System.out.println(list); } public static class Computer { private String name; private Integer price; private Integer speed; public Computer(String name, Integer price, Integer speed) { this.name = name; this.price = price; this.speed = speed; } public Integer getPrice() { return price; } public void setPrice(Integer price) { this.price = price; } public Integer getSpeed() { return speed; } public void setSpeed(Integer speed) { this.speed = speed; } // ... toString 方法 } }