/*
object类，所有的类都继承object类
tostring()对象的字符串的描述
hashcode（）返回对象的哈希码
equals()判断两个对象内容是否相等
重写equals()方法，必须重写hashcode（）方法
clone()创建并返回此对象的副本
要想一个类的对象能够克隆，必须实现两点
1：实现Cloneable接口（声明式接口，没要实现的方法）
2：重写object继承的clone()方法
*/
class people implements Cloneable{    private String name;    private int age;    public people()    {    }    public people(String name,int age)    {        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;    }    public String toString() {  //重写父类的tostring(),不然返回对象名+哈希码（十六进制）        return "name:"+this.getName()+",age"+this.getAge();    }    /*    public String toString() {        // TODO Auto-generated method stub        return super.toString();    }*/    @Override    public boolean equals(Object obj) {        if (obj instanceof people) { //是否为people            people people=(people) obj;            if (this.getName().equals(people.getName())&&(this.getAge()==people.getAge())) {                return true;            }            else {                return false;            }        }        else {            return false;        }    }    @Override    public int hashCode() {        // TODO Auto-generated method stub        return this.getName().hashCode()+this.getAge();    }    @Override    protected Object clone() throws CloneNotSupportedException {        // TODO Auto-generated method stub        return super.clone();    }        }public class main {    public static void main(String[] args) {        people aPeople=new people("jack", 23);        System.out.println(aPeople); //people@59ec59df,没重写tostring()        System.out.println(aPeople); //name:jack,age23,重写tostring()        System.out.println("aPeople的hashCode"+aPeople.hashCode());//aPeople的hashCode1508661727        //打印出的是十进制的哈希码，和没重写tostring()方法的十六进制值相等        //两个对象equales,他们的hashcode一定相等        //两个对象不相等，他们的hangcode有可能相等        people aPeople1=new people("jack", 23);//new的话是一个新对象        System.out.println("aPeople1的hashCode"+aPeople1.hashCode());//aPeople1的hashCode1343958201        System.out.println(aPeople==aPeople1);//地址不相同，返回false        System.out.println(aPeople.equals(aPeople1));//返回false ？        //说明：equals比较两者的内容是否相等，看上去两者内容相等，当没有重写它的equals方法时候，        //默认比较的是他们的hashcode，对于上面2个对象，hashcode肯定不同，故返回false        System.out.println(aPeople.equals(aPeople1));//重写equals后return true        String a=new String("jack");        String b=new String("jack");        System.out.println(a==b); //return false;        System.out.println(a.equals(b)); //return true;  ?        System.out.println(a.hashCode()==b.hashCode()); //return true; ?        //这边为什么又是true呢？因为String类(特殊的类)重写了hachcode和equals方法        System.out.println(System.identityHashCode(a));        System.out.println(System.identityHashCode(b)); //重写前的hashcode值是不同的                //people p3=aPeople1; //这样clone的话p3改变的话对apeople1也有影响        try {            people p4=(people) aPeople1.clone();            p4.setName("xiaoming");            System.out.println(p4);  //这样的话是copy的副本，输出结果不一样            System.out.println(aPeople1); //clone，改变p4对apeople1没影响        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }            }}