Spring 中的 IoC 的實現原理就是工廠模式加反射機制。

1. interface Fruit {

2. public abstract void eat();

3. }

4. class Apple implements Fruit {

5. public void eat(){

6. System.out.println("Apple");

7. }

8. }

9. class Orange implements Fruit {

10. public void eat(){

11. System.out.println("Orange");

12. }

13. }

14. class Factory {

15. public static Fruit getInstance(String ClassName) {

16. Fruit f=null;

17. try {

18. f=(Fruit)Class.forName(ClassName).newInstance();

19. } catch (Exception e) {

20. e.printStackTrace();

21. }

22. return f;

23. }

24. }

25. class Client {

26. public static void main(String[] a) {

27. Fruit f=Factory.getInstance("io.github.dunwu.spring.Apple");

28. if(f!=null){

29. f.eat();

30. }

31. }

32. }

Spring IoC 的實現機制