TreeSet实现排序(一)

package cn.cp;import java.util.Iterator;import java.util.TreeSet;//存入TreeSet集合中的元素是无序的，但有方法给它排序//排序方式一：让元素自身具备比较性，需元素实现Comparable接口//核心：重写Comparable接口的方法compareTo(Object obj)//if (tea.age == this.age) //年纪相同时再按照姓名排序！！！//         return this.name.compareTo(tea.name);//因为String也类实现了此接口，当然就可以调用compareTo()方法class Teacher implements Comparable {private int age;private String name;public Teacher(int age, String name) {this.age = age;this.name = name;}public int getAge() {return age;}public String getName() {return name;}@Overridepublic String toString() {return "Teacher [age=" + age + ", name=" + name + "]";}@Overridepublic int compareTo(Object obj) {//按照年纪排序Teacher tea = (Teacher) obj;if (tea.age < this.age) {return -1;}if (tea.age == this.age) {//年纪相同时再按照姓名排序！！！核心return this.name.compareTo(tea.name);}if (tea.age > this.age) {return 1;}return 0;}}public class TreeSetTest1 {public static void main(String[] args) {        Teacher teac1=new Teacher(25, "lim");        Teacher teac2=new Teacher(26, "uim");        Teacher teac3=new Teacher(55, "zim");        Teacher teac4=new Teacher(55, "mim");        Teacher teac5=new Teacher(55, "cim");        TreeSet treeSet=new TreeSet();        treeSet.add(teac1);        treeSet.add(teac2);        treeSet.add(teac3);        treeSet.add(teac4);        treeSet.add(teac5);        Iterator iterator=treeSet.iterator();        while(iterator.hasNext()){        Teacher t=(Teacher) iterator.next();        System.out.println(t.getName()+"的年纪是"+t.getAge());        }}}