Moder Java-WeAreDevelopers - Berlin - 2024.pdf

My presentation at WADWC in Berlin in July 2024 featuring the new additions and changes to the Java programming language

1. 

Modern Java
Ron Veen
Berlin, July 2024
WeAreDevelopers
World Congress

2. Agenda
1.Virtual threads
2.Structured Concurrency
3.Scoped Values
12. Unnamed class and instance main methods.
13. Module Imports
14. Launch multi-file source code programs
15. Markdown Documentation
Faster
4. Record patterns
5. Unnamed patterns and variables
6. Unnamed patterns
7. Primitive patterns
8. Sequenced Collections
9. Statements before super
10. Stream Gatherers
11. Generational ZGC
Better Easier

3. Virtual Threads

4. Java Threads

5. Virtual Threads

6. Factory methods

7. Virtual Thread Per Task Executor

8. Structured Concurrency

9. Structured Concurrency

10. Structured Concurrency

11. Invoke All pattern

12. Invoke Any pattern

13. Scoped Values

14. Thread Locals
1.Share information between different components of your application
2.Create a ThreadLocal instance that is reachable from anywhere
3.You can provide an initial value on creation
4.Or set a value using set (T value)
5.Retrieve the value anywhere via get( )

15. The problem with Thread Locals
1.Mutable
2.Resource intensive
3.Leaking

16. Enter Scoped Values
1.Exist for a limited time (lifetime of the Runnable)
2.Only the thread that wrote the value can read it
3.Immutable
4.Passed by reference

17. Scoped Values

18. Record Pattern Matching

19. Switch Pattern Matching

20. Switch Pattern Matching

21. Switch Pattern Matching

22. Switch Pattern Matching

23. Record Pattern Matching

24. Record Pattern Matching
•Checks if the object is of type BlueWingRec
•If so:
•Create 4 local variables
•Long id
•String name
•String email
•Boolean active
•Assigns the value if BlueWingRec.id to id
•Assigns the value of BlueWingRec.name to name
•Assigns the value of BlueWingRec.email to email
•Assigns the value of BlueWingRec.active to active

25. Unnamed Patterns And Variables

26. Unnamed Patterns And Variables

27. Unnamed Patterns And Variables

28. Unnamed Patterns And Variables

29. Primitive Patterns, InstanceOf, And Switch

30. Primitive In Patterns, InstanceOf, And Switch

31. Sequenced Collections

32. Sequenced Collections

33. Sequenced Collections

34. Flexible Constructor Bodies
(Statements Before Super)

35. Statements Before Super
Child
Parent
Object
super( )
super( )

36. Statements Before Super

37. Stream Gatherers

38. Stream setup
List.of("One", "Two", "Three", "Four", "Five")
.stream()
.filter(e -> !e.startsWith("T"))
.map(e -> e.toUpperCase())
.collect(Collectors.toList());

39. Stream sources
•Collections types
•Stream.of

40. Terminal Operations
•findFirst, findAny, etc.
•min, max
•Collectors.toCollection
•Collectors.toMap, Collectors.toList
•toList
•Implement your own via implementing the Collector interface

41. Intermediate Operations
•limit
•filter
•map
•flatMap
•takeWhile
•dropWhile
•skip
•sorted
•distinct

42. New Intermediate Operations
•mapConcurrent
•fold
•scan
•windowFixed
•windowSliding

43. Stream Gatherers

44. Stream Gatherers
●Initializer
●Integrator
●Finisher
●Combiner

45. Gatherer API

46. Create our own Map operation (stateless)

47. Generational ZGC

48. Generational ZGC
●Based on ZGC
●Pause times lower than one millisecond
●Support for heap sizes up yo many terabytes
●Minimal manual configuration
●Reduced risk of allocation stalls
●Decreased heap memory overhead requirements
●Lowered garbage collection CPU overhead

49. Generational ZGC
●Weak generational hypothesis
●Two-generation heap structure
●Young generation
●Old generation
●Now the default GC
●java -XX:+ZGenerational

50. Unnamed Classes and Instance Main Methods
(Implicitly Declared Classes And Instance Main Methods)

51. Unnamed Classes And Instance Main Methods

52. Unnamed Classes And Instance Main Methods

53. Module Imports

54. Module Imports
●Explicitly import classes -> import java.Util.List
●Import with wildcards -> import java.util.*
●Import everything in a module
●Import module java.base would import 54 on-demand package imports

55. Module Imports

56. Module Imports

57. Launch Multi-File Source Code Program

58. Launch Multi-File Source Code Program
●Running source file from java was introduced in Java 11
●Does not require the source code to be compiled into byte code upfront
●Compiles the source code to memory and executes the main method
●Only direct java directly referenced java files are included

59. Markdown Documentation Comments

60. Markdown Documentation Comments

61. Who is Ron Veen
@ronveen
ronveen @[email protected]
●Java developer for 20+ years
●Special Agent @ Team Rockstars IT
●Author:
●Migrating to cloud-native Jakarta EE
●Project Loom
@ronveen
.bsky.social