Java Set接口

 

 

class Person implements Comparable<Person>{
	private String name;
	private int age;
	
	public Person(String name, int age) {
		this.name = name;
		this.age = age;
	}

	@Override
	public String toString() {
		return "Poson [name=" + name + ", age=" + age + "]";
	}

	public int compareTo(Person o) {
		// TODO Auto-generated method stub
		if(this.age>o.age){
			return 1;
		}else if(this.age<o.age){
			return -1;
		}
		return 0;
	}

}
public class TreeDemo {
	public static void main(String[] args) {
		Set <Person> set=new TreeSet<>();
		set.add(new Person("张三", 58));
		set.add(new Person("李四", 12));
		set.add(new Person("晴儿", 45));
		set.add(new Person("赵三", 86));
		set.add(new Person("秦始皇", 15));
		System.out.println(set);
		
	}
}

 

class Person implements Comparable<Person>{
	String name;
	 int age;
	
	public Person(String name, int age) {
		this.name = name;
		this.age = age;
	}

	@Override
	public String toString() {
		return "Poson [name=" + name + ", age=" + age + "]";
	}

	public int compareTo(Person o) {
		// TODO Auto-generated method stub
		if(this.age>o.age){
			return 1;
		}else if(this.age<o.age){
			return -1;
		}
		return 0;//两个对象为同一个对象
	}

}
public class TreeDemo {
	public static void main(String[] args) {
		Set <Person> set=new TreeSet<>();
		set.add(new Person("张三", 58));
		set.add(new Person("李四物", 12));
		set.add(new Person("晴", 45));
		set.add(new Person("秦始皇2", 15));
		System.out.println(set);
		System.out.println("----------------------------------------------------");
		Set <Person> set1=new TreeSet<>(new nameLengthComparable());
		set1.add(new Person("张三", 58));
		set1.add(new Person("李四物", 12));
		set1.add(new Person("晴", 45));
		set1.add(new Person("秦始皇2", 15));
		System.out.println(set1);
		
	}
}
//名字长度比较器
class nameLengthComparable implements Comparator<Person>{

	@Override
	public int compare(Person o1, Person o2) {
		// TODO Auto-generated method stub
		if(o1.name.length()>o2.name.length()){
			return 1;
		}else if(o1.name.length()<o2.name.length()){
			return -1;
		}
		return 0;
	}