深度克隆的两种方式 （1）通过clone，并且克隆内部元素 - 克隆对象需要实现Cloneable接口 - 内部对象也要实现这个接口 - 克隆的时候要克隆内部对象
public class Person implements Cloneable { public Holder holder = new Holder(); @Override protected Object clone() throws CloneNotSupportedException { Person p= (Person) super.clone(); Holder holder=(Holder) holder.clone(); p.holder= holder; return p; } } class Holder implements Cloneable{ public String key = null; public Object value = null; @Override protected Object clone() throws CloneNotSupportedException { return super.clone(); } }（2）通过序列化克隆 - 实现序列化Serializable接口 - 内部对象也要实现Serializable接口 - 对所有对象序列化
public class Worker implements Serializable { public Holder2 holder = new Holder2(); @Override protected Object clone() throws CloneNotSupportedException { try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream outputStream = new ObjectOutputStream(bos); outputStream.writeObject(this); ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray()); ObjectInputStream ois = new ObjectInputStream(bis); return ois.readObject(); } catch (IOException e) { return null; } catch (ClassNotFoundException e) { return null; } } } class Holder2 implements Serializable { public String key = null; public Object value = null; }to be continue
