泛型2

import java.util.*;class Demo {public static void main(String[] args) {TreeSet<Student> ts=new TreeSet<Student>(new Comp());ts.add(new Student("zhangsan1"));ts.add(new Student("lisi2"));ts.add(new Student("wangwu3"));Iterator<Student> it=ts.iterator();while(it.hasNext()){System.out.println(it.next().getName());}TreeSet<Worker> ts1=new TreeSet<Worker>(new Comp());ts1.add(new Worker("wozhangsan1"));ts1.add(new Worker("wolisi2"));ts1.add(new Worker("wowangwu3"));Iterator<Worker> it1=ts1.iterator();while(it1.hasNext()){System.out.println(it1.next().getName());}}}class Comp implements Comparator<Person>{public int compare(Person s1,Person s2){return s1.getName().length()-s2.getName().length();}}class Person{private String name;public Person(String name){this.name=name;}public String getName(){return name;}}class Student extends Person{public Student(String name){super(name);}}class Worker extends Person{public Worker(String name){super(name);}}