实体类：

public class Person {public String getCode() {return code;}public void setCode(String code) {this.code = code;}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 String getAddress() {return address;}public void setAddress(String address) {this.address = address;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public Person(String code,String name,int age,String address,String sex){this.code = code;this.name = name;this.age = age;this.address = address;this.sex = sex;}private String code;private String name;private int age;private String address;private String sex; public String toString(){return this.code + "-" + this.name + "-" + this.age + "-" + this.address + "-" +this.sex;}
}

 

一、Comparator接口排序

import java.util.Comparator;/*** 根据年龄排序* @author wangxc**/
public class ageCompare implements Comparator<Person>{@Overridepublic int compare(Person person1, Person person2) {// TODO Auto-generated method stubreturn (person1.getAge() - person2.getAge());}
}

import java.util.Comparator;/*** 根据姓名排序* @author wangxc**/
public class nameCompare implements Comparator<Person>{@Overridepublic int compare(Person person1, Person person2) {// TODO Auto-generated method stubreturn person1.getName().compareTo(person2.getName());}
}

 

import java.util.*;public class Sort{public static void main(String[] args) throws Exception {ArrayList<Person> persons = new ArrayList<Person>();persons.add(new Person("001", "tom", 55, "NewYork","w"));persons.add(new Person("042", "jack", 25, "China","w"));persons.add(new Person("035", "allice", 39, "japan","m"));persons.add(new Person("023", "lili", 21, "England","m"));ageCompare ac = new ageCompare();Collections.sort(persons, ac);System.out.println("sort by age" + persons);nameCompare nc = new nameCompare();Collections.sort(persons, nc);System.out.println("sort by name" + persons);}		
}

 

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 二、Comparable接口排序，需要重写Comparable接口

修改实体类如下图所示，先根据年龄进行排序，再根据名字长度进行排序：

public class Person implements Comparable<Person>{public String getCode() {return code;}public void setCode(String code) {this.code = code;}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 String getAddress() {return address;}public void setAddress(String address) {this.address = address;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public Person(String code,String name,int age,String address,String sex){this.code = code;this.name = name;this.age = age;this.address = address;this.sex = sex;}private String code;private String name;private int age;private String address;private String sex; public String toString(){return this.code + "-" + this.name + "-" + this.age + "-" + this.address + "-" +this.sex;}@Overridepublic int compareTo(Person o) {// TODO Auto-generated method stubif (this.age < o.age) {  //return -1;}else if(this.age > o.age){return 1;}else {return this.name.compareTo(o.name);}}
}

import java.util.*;public class hehe {public static void main(String[] args) throws Exception {ArrayList<Person> persons = new ArrayList<Person>();persons.add(new Person("001", "tom", 55, "NewYork","w"));persons.add(new Person("042", "jack", 25, "China","w"));persons.add(new Person("035", "allice", 39, "japan","m"));persons.add(new Person("023", "lili", 21, "England","m"));Collections.sort(persons);System.err.println(persons);}		
}

 

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三、ArrayList.sort()  排序 

实体类无需修改代码，无需继承任何接口。

import java.util.*;public class hehe {public static void main(String[] args) throws Exception {ArrayList<Person> persons = new ArrayList<Person>();persons.add(new Person("001", "tom", 55, "NewYork","w"));persons.add(new Person("042", "jack", 25, "China","w"));persons.add(new Person("035", "allice", 39, "japan","m"));persons.add(new Person("023", "lili", 21, "England","m"));persons.sort((p1,p2) -> (p1.getAge() - p2.getAge()));//根据年龄进行排序System.out.println(persons);}		
}

 

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四、Comparator.comparing() 排序

import java.util.*;public class hehe {public static void main(String[] args) throws Exception {ArrayList<Person> persons = new ArrayList<Person>();persons.add(new Person("001", "tom", 55, "NewYork","w"));persons.add(new Person("042", "jack", 25, "China","w"));persons.add(new Person("035", "allice", 39, "japan","m"));persons.add(new Person("023", "lili", 21, "England","m"));//先根据年龄排序再根据名字排序最后反转序列persons.sort(Comparator.comparing(Person::getAge).thenComparing(Person::getName).reversed());System.out.println(persons);}		
}