comparable和comparator区别

import java.util.Iterator;
import java.util.TreeSet;

/**
 * @author WangShuang
 *
 */
public class Demo {
    public static void main(String[] args) {
        Person p0 = new Person("张三",3);
        Person p = new Person("张三",1);
        Person p1 = new Person("张三",2);
        Person p2 = new Person("张四",2);
        Person p3 = new Person("张四",2);

        TreeSet<Person> treeSet=new TreeSet<Person>();
        treeSet.add(p0);
        treeSet.add(p);
        treeSet.add(p1);
        treeSet.add(p2);
        treeSet.add(p3);

        Iterator<Person> iterator = treeSet.iterator();
        while(iterator.hasNext()){
            Person next = iterator.next();
            System.out.println(next);
        }
    }
}
class Person implements Comparable<Person>{//该接口强制让人具有比较性
    private String name;
    private int age;
    public Person(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;
    }
    @Override
    public int compareTo(Person o) {
        if(this.age>o.age){
            return 1;
        }else if(this.age<o.age){
            return -1;
        }else{
            return this.name.compareTo(o.name);
        }
    }
    @Override
    public String toString() {
        return "Person [name=" + name +  ", age=" + age + "]";
    }
}

通过comparator方式

import java.util.Comparator;
import java.util.Iterator;
import java.util.TreeSet;

/**
 *  
 * @author WangShuang
 *
 */
public class Demo {
    public static void main(String[] args) {
        Person p0 = new Person("张三",3);
        Person p = new Person("张三",1);
        Person p1 = new Person("张三",2);
        Person p2 = new Person("张四",2);
        Person p3 = new Person("张四",2);

        TreeSet<Person> treeSet=new TreeSet<>(new Com());
        treeSet.add(p0);
        treeSet.add(p);
        treeSet.add(p1);
        treeSet.add(p2);
        treeSet.add(p3);

        Iterator<Person> iterator = treeSet.iterator();
        while(iterator.hasNext()){
            Person next = iterator.next();
            System.out.println(next);
        }
    }
}
class Com implements Comparator<Person>{//该接口强制让集合具有比较性
    @Override
    public int compare(Person o1, Person o2) {
        if(o1.getAge()>o2.getAge()){
            return 1;
        }else if(o1.getAge()<o2.getAge()){
            return -1;
        }else{
            return o1.getName().compareTo(o2.getName());
        }
    }
}

class Person{
    private String name;
    private int age;
    public Person(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;
    }
    @Override
    public String toString() {
        return "Person [name=" + name +  ", age=" + age + "]";
    }
}

comparable和comparator区别

原文：http://blog.51cto.com/13579086/2070527