Core Java instance-interface Abstraction

 

Interface Usage:

 

1. Use the interface with Polymorphism: It is divided into the status at compile time and runtime.

2. Pay attention to the consistency of objects.

3. Forced conversion.

 

 

1. Package com;
3. Public interface animal {
5. }

 

1. Package com;
3. /***
4. *
5. * Birds
6. *
7. * @ Author Administrator
8. *
9. */
10. Public class bird implements animal {
12. Public bird (){
14. }
16. Public String color;
17. Private int age;
19. Public int getage (){
20. Return age;
21. }
23. Public void setage (INT age ){
24. This. Age = age;
25. }
27. Public String getcolor (){
28. Return color;
29. }
31. Public void setcolor (string color ){
32. This. Color = color;
33. }
36. }

 

1. Package com;
3. Public class samllbird extends bird {
5. }

 

 

1. Package com;
3. Import java. Lang. Reflect. invocationtargetexception;
6. Public class test {
9. Public static void main (string [] ARGs) throws classnotfoundexception, securityexception, nosuchfieldexception, illegalargumentexception, illegalaccessexception, nosuchmethodexception, invocationtargetexception {
11. Animal B = new bird ();
12. B. tostring ();
14. Bird = (BIRD) B;
15. Bird. setcolor ("red ");
17. System. Out. println (bird. getcolor ());
19. System. Out. println (B = bird );
21. Animal sb = new samllbird ();
22. Bird BB = (BIRD) Sb;
23. System. Out. println (SB = bb );
25. System. Out. println (B instanceof animal );
26. System. Out. println (bird instanceof animal );
27. System. Out. println (SB instanceof animal );
32. }
34. }

Running result:

Red True True True True True