protected Object clone()
        throws CloneNotSupportedException

//原始类型
int a = 1;
int b = a;

//引用类型
String[] weekdays = new String[5];
String[] gongzuori = weekdays;//仅拷贝引用

public interface Cloneable {
}

static class CloneableImp implements Cloneable {
 public int count;
 public Child child;
   
   
 @Override
 public Object clone() throws CloneNotSupportedException {
   return super.clone();
 }
}

CloneableImp imp1 = new CloneableImp();
imp1.child = new Child("Andy");
try {
 Object obj = imp1.clone();
 CloneableImp imp2 = (CloneableImp)obj;
 System.out.println("main imp2.child.name=" + imp2.child.name);
} catch (CloneNotSupportedException e) {
 e.printStackTrace();
}

CloneableImp imp1 = new CloneableImp();
imp1.child = new Child("Andy");
try {
 Object obj = imp1.clone();
 CloneableImp imp2 = (CloneableImp)obj;
 imp2.child.name = "Bob";
     
 System.out.println("main imp1.child.name=" + imp1.child.name);
} catch (CloneNotSupportedException e) {
 e.printStackTrace();
}

main imp1.child.name=Bob

public class Child implements Cloneable{

 public String name;

 public Child(String name) {
   this.name = name;
 }

 @Override
 public String toString() {
   return "Child [name=" + name + "]";
 }

 @Override
 protected Object clone() throws CloneNotSupportedException {
   return super.clone();
 }
}

static class CloneableImp implements Cloneable {
 public int count;
 public Child child;
   
   
 @Override
 public Object clone() throws CloneNotSupportedException {
   CloneableImp obj = (CloneableImp)super.clone();
   obj.child = (Child) child.clone();
   return obj;
 }
}

public class Car {
 Wheel wheel;
 String manufacturer;
 
 public Car(Wheel wheel, String manufacturer) {
   this.wheel = wheel;
   this.manufacturer = manufacturer;
 }
 
 //copy constructor
 public Car(Car car) {
   this(car.wheel, car.manufacturer);
 }
 
 public static class Wheel {
   String brand;
 }
}

//copy constructor
public Car(Car car) {
 Wheel wheel = new Wheel();
 wheel.brand = car.wheel.brand;
   
 this.wheel = wheel;
 this.manufacturer = car.manufacturer;
}

public static Car newInstance(Car car) {
 return new Car(car);
}

public class DeepCopyExample implements Serializable{
 private static final long serialVersionUID = 6098694917984051357L;
 public Child child;
 
 public DeepCopyExample copy() {
   DeepCopyExample copy = null;
   try {
     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     ObjectOutputStream oos = new ObjectOutputStream(baos);
     oos.writeObject(this);
 
     ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
     ObjectInputStream ois = new ObjectInputStream(bais);
     copy = (DeepCopyExample) ois.readObject();
   } catch (IOException e) {
     e.printStackTrace();
   } catch (ClassNotFoundException e) {
     e.printStackTrace();
   }
   return copy;
 }
}

public class Child implements Serializable{
 private static final long serialVersionUID = 6832122780722711261L;
 public String name = "";

 public Child(String name) {
   this.name = name;
 }

 @Override
 public String toString() {
   return "Child [name=" + name + "]";
 }
}

DeepCopyExample example = new DeepCopyExample();
example.child = new Child("Example");
   
DeepCopyExample copy = example.copy();
if (copy != null) {
 copy.child.name = "Copied";
 System.out.println("example.child=" + example.child + ";copy.child=" + copy.child);
}
//输出结果：example.child=Child [name=Example];copy.child=Child [name=Copied]