TreeSet类

1.自然排序

2.存储对象

对象实现Comparable接口

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

public class TreeSetDemo {
    public static void main(String[] args){
        TreeSet<Student> ts =new TreeSet<Student>();
        ts.add(new Student(21,"zhangsan"));
        ts.add(new Student(29,"lisi"));
        ts.add(new Student(23,"zhangsan"));
        Iterator<Student> it =ts.iterator();
        while(it.hasNext()){
            Student s = it.next();
            System.out.println(s.getAge()+"..."+s.getName());
        }
        
    }
}
class Student implements Comparable<Student>{
    public Student(int age, String name) {
        super();
        this.age = age;
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    private int age;
    private String name;
    @Override
    public int compareTo(Student s) {
        int num = this.name.compareTo(s.name);
        if(num==0)
            return new Integer(this.age).compareTo(new Integer(s.age));
        return num;
    }
    
}

实现Comparator接口

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

public class TreeSetDemo {
    public static void main(String[] args){
        TreeSet<Student> ts =new TreeSet<Student>(new MyComp());
        ts.add(new Student(21,"zhangsan"));
        ts.add(new Student(29,"lisi"));
        ts.add(new Student(23,"wangwu"));
        Iterator<Student> it =ts.iterator();
        while(it.hasNext()){
            Student s = it.next();
            System.out.println(s.getAge()+"..."+s.getName());
        }
        
    }
}
class Student  {
    public Student(int age, String name) {
        super();
        this.age = age;
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    private int age;
    private String name;
    
}
class MyComp implements Comparator<Student>{

    @Override
    public int compare(Student o1, Student o2) {
        int num = o1.getName().compareTo(o2.getName());
        if(num==0)
            return new Integer(o1.getAge()).compareTo(new Integer(o2.getAge()));
        return num;

    }
    
}

3.二叉树

4.TreeSet练习