The document summarizes a Java developer's experience learning .NET over 5 days. On day 1, they define .NET Framework, .NET Core, and .NET Standard. On day 2, they discuss C# as the main .NET language. On day 3, they cover .NET frameworks like ASP.NET Core. On day 4, they examine the .NET ecosystem compared to Java. On day 5, they propose the idea of a JHipster-like framework called JHipster.NET to enhance .NET Core and focus on developer experience.

1. Diary of a Java dev lost in
the .Net world
JHipsterConf, 27/06/2019
1

2. Who are you?
● .Net (core)
○ C#?
● Java
○ Java?
○ Kotlin?
○ Groovy?
○ Scala?
○ Golo??
● JHipster?
● Vert.x?
2

3. @gaultierlarge + @FlorianGourdeau
3

4. @danielpetisme
@lavajug
@golo_lang
@vertx_project
@java_hipster
@Michelin
4

5. JVM
5

6. 6

7. 7

8. Day#1: The definitions
8

9. What the hell is .Net?
9

10. .Net Framework vs .Net Core vs .Net Standard
10

11. Day#2: The language
11

13. 13

14. My Top3

15. Data Objects
var userDto = new UserDto {
Login = "not-used",
FirstName = "firstname",
LastName = "lastname",
Email = "save-existing-email-and-login@example.com",
Activated = false,
ImageUrl = "http://placehold.it/50x50",
LangKey = Constants.DefaultLangKey,
Roles = new HashSet<string> {
RolesConstants.USER
}
};
https://try.dot.net/?fromGist=c9fa9087655d352b5a4d594bb228e948
15

16. Async native (1/2)
public async Task<User> CreateUser(UserDto userDto)
{
var user = new User {
UserName = userDto.Login.ToLower(),
FirstName = userDto.FirstName,
LastName = userDto.LastName,
Email = userDto.Email.ToLower(),
ImageUrl = userDto.ImageUrl,
LangKey = userDto.LangKey ?? Constants.DefaultLangKey,
PasswordHash = "..."
ResetKey = RandomUtil.GenerateResetKey(),
ResetDate = DateTime.Now,
Activated = true
};
await _userManager.CreateAsync(user);
await CreateUserRoles(user, userDto.Roles);
_log.LogDebug( $"Created Information for User: {user}");
return user;
}
https://try.dot.net/?fromGist=c9fa9087655d352b5a4d594bb228e948
16

17. Reactive eXtensions
17

18. Extensions (1/3)
https://try.dot.net/?fromGist=aa789fa70bcd0e5db2aac00018be0c5f
public static class StringExtension
{
public static string Capitalize(this string str) {
return char.ToUpper(str[0]) + str.Substring(1);
}
public static string Decorate(this string str, string decoration) => $"{decoration} {str} {decoration}";
}
public class Program
{
public static void Main()
{
Console.WriteLine("java".Capitalize());
Console.WriteLine("Java + C#".Decorate("🧡"));
}
}
18

19. Extensions (2/3)
public static class WebConfiguration {
public static IServiceCollection AddWebModule( this IServiceCollection @this)
{
@this.AddHttpContextAccessor();
//https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/health-checks?view=aspnetcore-2.2
@this.AddHealthChecks();
@this.AddMvc(options => {
options. ModelBinderProviders.Insert(0, new PageableBinderProvider());
})
.SetCompatibilityVersion(CompatibilityVersion. Version_2_2)
.AddJsonOptions(options => {
options. SerializerSettings.NullValueHandling = NullValueHandling. Ignore;
});
return @this;
}
}
19

20. Extensions (3/3)
public void ConfigureServices(IServiceCollection services)
{
services
.AddDatabaseModule( Configuration)
.AddSecurityModule()
.AddProblemDetailsModule()
.AddAutoMapperModule()
.AddWebModule()
.AddSwaggerModule();
}
20

21. Type inference 2007 2018
Data objects 2007 N/A
Extensions 2007 N/A
Traits 2018 2014
String Interpolation 2015 N/A
C# > Java ?

22. JVM rulezz

23. CLR ???

24. https://www.jetbrains.com/rider/
24

25. Day#3 Frameworks
25

26. 26

27. 27

28. “Just enough to not start from scratch,
not enough to be enterprise-friendly”
28

30. Issues
Action/Headers weird with HTTP APIs
Pagination
DbConcurrencyException (catch’em all)
Manual DI
Configure file Management
Audit
Testing fixtures
30

31. Day#4: The ecosystem
31

32. 32

33. https://octoverse.github.com/projects#repositories
33

34. .Net Developper in 2019
34

35. 4years...
Fancy a PR?
https://github.com/aspnet/EntityFrameworkCore/issues/1368#issuecomment-473521834
35

36. Java, open by nature
36

37. Java-ish foundations
37

38. .Net Foundation
��
38

39. Day#5: JHipster.Net
39

40. 40

41. Objectives
● Enhance (Asp.Net|Entity Framework) Core
○ Pagination
○ Security|identity
○ Audit trail
● Focus on Developer eXperience
○ Opinionated standards based on community proposals
○ CRUD generation
○ Binary packaging
○ Environment management
○ Docker
● Reuse frontend generation
○ Angular|React|Vue.js
41

42. 42

43. 43

44. 44

45. CGI (Grenoble) and open source
45

46. CGI (Grenoble) and Jhipster
46

47. EF Core vs Hibernate
● Eager loading
● Many to many
47

48. Demo !
48

49. What’s next?
● Client
○ React/Vue.js
● Entity Server
○ Testing Generation
● Entity Client
○ Code Generation
○ Testing Generation
● Global
○ Blueprint test
○ DX (docker, quality, etc.)

50. Join us to develop Jhispter .Net
https://github.com/jhipster/jhipster-dotnetcore
https://github.com/jhipster/jhipster-net-sample-app-template
50

51. Q&A
51