detailed reference to http://blog.youkuaiyun.com/longronglin/archive/2008/05/17/2454652.aspx
public abstract class Person implements PersonProperity, Cloneable,
Comparable<Person>
/**
* implements compareTo
*/
public int compareTo(Person p) {
if (this.age > p.age) {
return 1;
} else if (this.age < p.age) {
return -1;
} else {
if(this.name.compareTo(p.name) > 0)
{