Java & 混型

#include <string>
#include <ctime>
#include <iostream>
using namespace std;

template<class T> class TimeStamped : public T {
  long timeStamp;
public:
  TimeStamped() { timeStamp = time(0); }
  long getStamp() { return timeStamp; }
};

template<class T> class SerialNumbered : public T {
  long serialNumber;
  static long counter;
public:
  SerialNumbered() { serialNumber = counter++; }
  long getSerialNumber() { return serialNumber; }
};

// Define and initialize the static storage:
template<class T> long SerialNumbered<T>::counter = 1;

class Basic {
  string value;
public:
  void set(string val) { value = val; }
  string get() { return value; }
};    

int main() {
  TimeStamped<SerialNumbered<Basic> > mixin1, mixin2;    //这就是我想要的
  mixin1.set("string1");
  mixin2.set("string2");
  cout << mixin1.get() << " " << mixin1.getStamp() << " " << mixin1.getSerialNumber() << endl;
  cout << mixin2.get() << " " << mixin2.getStamp() << " " << mixin2.getSerialNumber() << endl;
}

string1 1129840250 1
string2 1129840250 2

 1 interface TimeStamped { 
 2   long getStamp(); 
 3 }
 4 
 5 
 6 interface SerialNumbered {
 7     long getSerialNumber(); 
 8 }
 9 
10 
11 interface Basic {
12   public void set(String val);
13   public String get();
14 }

 1 class TimeStampedImp implements TimeStamped {
 2   private final long timeStamp;
 3   public TimeStampedImp() {
 4     timeStamp = new Date().getTime();
 5   }
 6   public long getStamp() { return timeStamp; }
 7 }
 8 
 9 
10 class SerialNumberedImp implements SerialNumbered {
11   private static long counter = 1;
12   private final long serialNumber = counter++;
13   public long getSerialNumber() { return serialNumber; }
14 }
15 
16 
17 
18 class BasicImp implements Basic {
19   private String value;
20   public void set(String val) { value = val; }
21   public String get() { return value; }
22 }

 1 class Mixin extends BasicImp implements TimeStamped, SerialNumbered {   
 2   private TimeStamped timeStamp = new TimeStampedImp();
 3   private SerialNumbered serialNumber =  new SerialNumberedImp();
 4 
 5   public long getStamp() { return timeStamp.getStamp(); }     //代理
 6   public long getSerialNumber() {                             //代理
 7     return serialNumber.getSerialNumber();
 8   }
 9 }
10 
11 public class Mixins {
12   public static void main(String[] args) {
13     Mixin mixin1 = new Mixin(); 
14     Mixin mixin2 = new Mixin();
15     mixin1.set("string1");
16     mixin2.set("string2");
17     System.out.println(mixin1.get() + " " + mixin1.getStamp() +  " " + mixin1.getSerialNumber());
18     System.out.println(mixin2.get() + " " + mixin2.getStamp() +  " " + mixin2.getSerialNumber());
19   }
20 }

 1 class Basic {
 2   private String value;
 3   public void set(String val) { value = val; }
 4   public String get() { return value; }
 5 }
 6 
 7 class Decorator extends Basic {
 8   protected Basic basic;
 9   public Decorator(Basic basic) { this.basic = basic; }
10   public void set(String val) { basic.set(val); }
11   public String get() { return basic.get(); }
12 }    
13 
14 class TimeStamped extends Decorator {
15   private final long timeStamp;
16   public TimeStamped(Basic basic) {
17     super(basic);
18     timeStamp = new Date().getTime();
19   }
20   public long getStamp() { return timeStamp; }
21 }
22 
23 class SerialNumbered extends Decorator {
24   private static long counter = 1;
25   private final long serialNumber = counter++;
26   public SerialNumbered(Basic basic) { super(basic); }
27   public long getSerialNumber() { return serialNumber; }
28 }    
29 
30 public class Decoration {
31   public static void main(String[] args) {
32     TimeStamped t = new TimeStamped( new Basic() );
33     TimeStamped t2 = new TimeStamped( new SerialNumbered( new Basic() ));
34     //! t2.getSerialNumber(); // Not available
35     SerialNumbered s = new SerialNumbered(new Basic());
36     SerialNumbered s2 = new SerialNumbered( new TimeStamped( new Basic() ));
37     //! s2.getStamp(); // Not available
38   }
39 }