浅拷贝：根本类型间接拷贝，援用类型拷贝内存地址！ 【能够间接通过 impliment Cloneable 来实现浅拷贝】
public class AddressEntity implements Cloneable {
private String city;private String country;public AddressEntity(String city, String country) { this.city = city; this.country = country;}// 省略get、set@Overridepublic Object clone() { try { return super.clone(); } catch (CloneNotSupportedException e) { e.printStackTrace(); } return null;}}
public class PersonEntity implements Cloneable {
private String username;private int age;private AddressEntity address;@Overridepublic PersonEntity clone() { try { return (PersonEntity) super.clone(); } catch (CloneNotSupportedException e) { return null; }}}
public static void cloneQian() {
AddressEntity address = new AddressEntity("杭州", "中国");PersonEntity p1 = new PersonEntity("骆佳俊", 24, address);// 拷贝对象PersonEntity p2 = p1.clone();// 原始对象和拷贝对象是否一样：System.out.println("原始对象和拷贝对象是否一样: " + (p1 == p2));// 原始对象和拷贝对象的name属性是否一样System.out.println("原始对象和拷贝对象的name属性是否一样: " + (p1.getUsername() == p2.getUsername()));// 原始对象和拷贝对象的subj属性是否一样System.out.println("原始对象和拷贝对象的subj属性是否一样: " + (p1.getAddress() == p2.getAddress()));p2.setUsername("ccc");p2.getAddress().setCity("宁波");System.out.println("更新后的原始对象: " + p1.getUsername() + " - " + p1.getAddress().getCity());System.out.println("更新原始对象后的克隆对象: " + p2.getUsername() + " - " + p2.getAddress().getCity());}
深拷贝：在对援用数据类型进行拷贝的时候，创立了一个新的对象，并且复制其内的成员变量。
实现形式:
- 实现cloneable接口
持续利用 clone()办法，对其内的援用类型的变量，再进行一次clone()，或者在clone()创立新的援用变量赋值和新的对象
public PersonEntity deepClone() throws CloneNotSupportedException { PersonEntity personClone = (PersonEntity) super.clone(); personClone.address = (AddressEntity) this.address.clone(); return personClone;}public static void deepClone() throws CloneNotSupportedException { AddressEntity address = new AddressEntity("杭州", "中国"); PersonEntity p1 = new PersonEntity("骆佳俊", 24, address); PersonEntity p2 = p1.deepClone(); p1.setAddress(new AddressEntity("宁波", "中国")); System.out.println(p2.getAddress()); System.out.println(p1.getAddress()); //AddressEntity{city='杭州', country='中国'} //AddressEntity{city='宁波', country='中国'}}最重要的代码就在 PersonEntity.clone() 中，它对其内的address ，再进行了一次 clone() 操作!
- 序列化与反序列化
序列化后将二进制字节流内容写到一个媒介（文本或字节数组），而后是从这个媒介读取数据，原对象写入这个媒介后拷贝给clone对象，原对象的批改不会影响clone对象，因为clone对象是从这个媒介读取。
public class AddressSearizableEntity implements Serializable {
private String city;private String country;@Overridepublic String toString() { return "AddressSearizableEntity{" + "city='" + city + '\'' + ", country='" + country + '\'' + '}';}// 省略get、set}
public class PersonSerializableEntity implements Serializable {
private String username;private int age;// 省略get、setpublic PersonSerializableEntity myClone() throws IOException, ClassNotFoundException { //序列化 ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = null; try { oos = new ObjectOutputStream(bos); oos.writeObject(this); } catch (IOException e) { e.printStackTrace(); } //反序列化 ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray()); ObjectInputStream ois = null; try { ois = new ObjectInputStream(bis); } catch (IOException e) { e.printStackTrace(); } return (PersonSerializableEntity) ois.readObject();}}
public static void main(String[] args) throws CloneNotSupportedException {
SpringApplication.run(HouseManageMentApplication.class, args); PersonSerializableEntity p1 = new PersonSerializableEntity("roger", 24, new AddressSearizableEntity("杭州", "中国")); try { PersonSerializableEntity p2 = p1.myClone(); p2.setAddress(new AddressSearizableEntity("宁波", "中国")); //AddressSearizableEntity{city='杭州', country='中国'},AddressSearizableEntity{city='宁波', country='中国'} System.out.println(p1.getAddress() + "," + p2.getAddress()); } catch (IOException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); }}