TreeSet多字段排序

package st;

public class PersonBean implements Comparable<Object>{

    private String name;

    private int age;

    PersonBean(String name, int age) {

        this.name = name;

        this.age = age;

    }

    public String getName() {

        return name;

    }

    public int getAge() {

        return age;

    }

    @Override

    public int compareTo(Object obj) {

        if (!(obj instanceof PersonBean))

            throw new RuntimeException();

        /**

         * 在这里定义比较对象大小的方法

         * 先进行年龄的比较，年龄不相等再进行姓名的比较

         * 如果年龄与姓名都相等，那么就代表同一个对象

         */

        PersonBean pe = (PersonBean) obj;

        if (this.age > pe.age)

            return ;

        if (this.age == pe.age) {

            return this.name.compareTo(pe.name);

        }

        return -;

    }

}

import java.util.Iterator;

import java.util.TreeSet;

public class Dup {

        public static void main(String[] args) {

            // 向这个集合中存储自定义对象

            TreeSet<PersonBean> ts = new TreeSet<PersonBean>();

            ts.add(new PersonBean("lishi", ));

            ts.add(new PersonBean("lishi1", ));

            ts.add(new PersonBean("lishi56", ));

            ts.add(new PersonBean("lishi4", ));

            //获取迭代器，取出其中的元素

            Iterator<PersonBean> it = ts.iterator();

            while (it.hasNext()) {

                PersonBean pe = (PersonBean) it.next();

                System.out.println(pe.getAge() + "  " + pe.getName());

            }

}

}