public class Person implements Comparable {

    private String name;
    private int age;
    
    public Person() {
        super();
    }
    public Person(String name, int age) {
        super();
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    
    /**
     * 建立了Person对象判断是否相同的依据。只要是同姓名同年龄就是同一个人
     * @param obj
     * @return
     */
    @Override
    public boolean equals(Object obj) {
        if(this == obj)
            return true;
        
        if(!(obj instanceof Person)){
            throw new ClassCastException("类型错误");
        }
        Person p = (Person)obj;
        
        return this.name.equals(p.name) && this.age == p.age;
    }
    /**
     * 比较年龄大小的方法。
     */
    
    
    @Override
    public String toString() {
        return "Person [name=" + name + ", age=" + age + "]";
    }
    @Override
    public int compareTo(Object o) {
        
        if(!(o instanceof Person)){
            throw new ClassCastException("类型错误");
        }
        
        Person p = (Person)o;
        /*
        if(this.age > p.age)
            return 1;
        if(this.age < p.age)
            return -1;
        return 0;*/
        return this.age - p.age;
        
    }
}

public class PersonDemo {

    /**
     * @param args
     */
    public static void main(String[] args) {
        
        Person p1 = new Person("lisi", 20);
        Person p2 = new Person("wangcai", 23);
        
        System.out.println(p1.compareTo(p2));
    }
}