The document outlines the evolution from Java 1.4 to Java 1.6, focusing on code enhancements, autoboxing features, and generics. It discusses various coding practices, such as using enhanced for loops, static imports, and varargs, while addressing potential pitfalls like class cast exceptions and inheritance issues with generics. Additionally, it touches on the transition from EJB 2 to EJB 3 in terms of session bean requirements.

1. 1

2. Plan
1. Example: from Java 1.4 to Java 1.6
2. Problems
3. Additional features
2

3. Code before Java 5/6
3

4. Simple for loop
4

5. Enhanced for loop
5

6. After the first enhancement
Untouched
part
Enhanced
part
6

7. Creating instances of Integer
7

8. Autoboxing
Works for:
 Boolean
 Byte
 Short
 Character
 Integer
 Long
 Float
 Double
8

9. Autoboxing usage
9

10. What about…
10

11. …type-safety
11

12. ClassCastException
12

13. Generics
13

14. Ensuring type-safety
14

15. Compilation exception
15

16. Enhanced for + generics
16

17. Code getting better…
17

18. Can it be shortened?
18

19. Simple usage
19

20. Static import
20

21. Static import of the System class
21

22. Creating a list
Code duplication
22

23. Desired outcome
23

24. First thought
24

25. Varargs
25

26. Creating a list with varargs
26

27. Generics + varargs
27

28. Time for a comparison
…
28

29. Before
After
29

30. Problems
1. Inheritance and generics
2. Class to be used with the enhanced for loop
3. Watch out! Autoboxing in a loop
4. When use the static import?
5. Rules for Varargs
30

31. Inheritance and generics
31

32. Iterating over domain class
32

33. Iterable<T> interface
33

34. Watch out! Autoboxing in a loop
34

35. How it really works…
35

36. 36

37. When use the static import?
 …firstly, try not to overuse it
 it works well if it makes your code more readable and
DRY, i.e.:
 JUnit 4 (org.junit.Assert.*);
 Mockito (org.mockito.Mockito.*);
37

38. Static import (JUnit 4)
38

39. Static import (Mockito)
39

40. Rules for varargs
40

41. Additional features
 Enums
 Annotations
41

42. Simple enum
42

43. Enum is a class
43

44. Annotations
…first lets get back to EJB 2…
…what is needed for a session bean in EJB 2?
44

45. Component interface
45

46. Home interface
46

47. Component class
47

48. ejb-jar.xml – dependencies
48

49. ejb-jar.xml – transactions
49

50. The same thing, but with EJB 3
50

51. The End
51