1
00:00:00,000 --> 00:00:02,590
[No Audio]

2
00:00:02,590 --> 00:00:04,112
In this video we're going to start to think

3
00:00:04,112 --> 00:00:06,694
about how we can code up a layered architecture.

4
00:00:06,694 --> 00:00:08,204
So in other words, an architecture with

5
00:00:08,204 --> 00:00:09,956
respects the three layers you have in

6
00:00:09,956 --> 00:00:12,488
a web application, that's presentation layer, service

7
00:00:12,488 --> 00:00:14,878
layer, and a data or persistence layer.

8
00:00:14,878 --> 00:00:16,771
And what we're going to do with this, is

9
00:00:16,771 --> 00:00:19,184
it will enable us to describe basically how

10
00:00:19,184 --> 00:00:21,416
we approach testing with mock objects, how we

11
00:00:21,416 --> 00:00:23,566
apply that to this layered architecture.

12
00:00:23,566 --> 00:00:25,726
So the next few videos might not seem so relevant

13
00:00:25,726 --> 00:00:28,076
to unit testing, but they are because it's important to

14
00:00:28,076 --> 00:00:31,083
understand how the lead architecture is coded, because

15
00:00:31,083 --> 00:00:33,223
then we can explain how we apply Mockito to that.

16
00:00:33,223 --> 00:00:35,072
So just hang in there for these next few videos.

17
00:00:35,072 --> 00:00:36,536
Bear with us while we cover this up,

18
00:00:36,536 --> 00:00:38,434
and then we'll pick up the Mockito testing

19
00:00:38,434 --> 00:00:40,784
aspect of it in a few videos time.

20
00:00:40,784 --> 00:00:43,006
So let's jump in now, and look at the controller.

21
00:00:43,006 --> 00:00:44,564
So we've got our project set up now,

22
00:00:44,564 --> 00:00:46,846
we can use Mockito and we've got JUnit installed.

23
00:00:46,846 --> 00:00:49,575
Let's just remove this code here because

24
00:00:49,575 --> 00:00:51,644
we don't really need this. That was just a test,

25
00:00:51,644 --> 00:00:53,827
we had everything set up okay.

26
00:00:53,827 --> 00:00:56,510
that's gone. Now it's plugging

27
00:00:56,510 --> 00:00:57,874
a couple of classes which interact

28
00:00:57,874 --> 00:01:00,536
with each other that we can demonstrate Mockito with.

29
00:01:00,536 --> 00:01:03,154
So if I go into here in the production source

30
00:01:03,154 --> 00:01:07,480
folder here and we'll just create a LoginController.

31
00:01:07,480 --> 00:01:11,170
So let's suppose this LoginController is responsible

32
00:01:11,170 --> 00:01:13,460
for serving web requests in a web application.

33
00:01:13,460 --> 00:01:16,724
So Http request comes in which passes the username and

34
00:01:16,724 --> 00:01:19,664
password to the users entered into HTML form.

35
00:01:19,664 --> 00:01:21,872
And this class is responsible for either

36
00:01:21,872 --> 00:01:23,624
presenting the user with the homepage if

37
00:01:23,624 --> 00:01:24,886
it's been logged in successfully.

38
00:01:24,886 --> 00:01:26,876
In other words, the password is what we expect and

39
00:01:26,876 --> 00:01:29,096
we've got a valid user, or if that isn't the

40
00:01:29,096 --> 00:01:31,652
case, it's going to reject the user and redirect him

41
00:01:31,652 --> 00:01:33,903
to go back to the login screen. So that's

42
00:01:33,903 --> 00:01:35,468
roughly what the LoginController is going to do.

43
00:01:35,468 --> 00:01:36,884
So let's write some code for that.

44
00:01:36,884 --> 00:01:39,870
[No Audio]

45
00:01:39,870 --> 00:01:41,616
Let's say that the controller returns back a

46
00:01:41,616 --> 00:01:42,828
string, which is either going to be a

47
00:01:42,828 --> 00:01:44,556
reference to the home page or some kind

48
00:01:44,556 --> 00:01:46,932
of instruction to redirect to the login page.

49
00:01:46,932 --> 00:01:47,988
Let's just keep it simple.

50
00:01:47,988 --> 00:01:50,004
We'll just return one of two strings, either

51
00:01:50,004 --> 00:01:52,224
slash home or slash login, depending on whether

52
00:01:52,224 --> 00:01:54,470
tha the user logged in successfully or didn't.

53
00:01:54,470 --> 00:01:57,087
Let's give it a service method, say.

54
00:01:57,087 --> 00:01:59,153
[No Audio]

55
00:01:59,153 --> 00:02:02,534
with a String username and a String password.

56
00:02:02,534 --> 00:02:04,633
Now obviously there are different types of framework

57
00:02:04,633 --> 00:02:07,117
out there to be able to code web apps in Java to the

58
00:02:07,117 --> 00:02:11,433
Spring MVC, for example, Java Servlets, JavaServer Faces

59
00:02:11,433 --> 00:02:13,716
we are going way back in time, Struts and those

60
00:02:13,716 --> 00:02:15,204
kinds of framework, and each one has

61
00:02:15,204 --> 00:02:16,896
its own different way of doing things.

62
00:02:16,896 --> 00:02:18,168
But don't worry about that now.

63
00:02:18,168 --> 00:02:19,538
Just focus on the fact that we're creating

64
00:02:19,538 --> 00:02:22,176
a LoginController which is hypothetical, and that

65
00:02:22,176 --> 00:02:24,276
LoginController sits on the web layer of

66
00:02:24,276 --> 00:02:26,534
the application and just purely deals with logic

67
00:02:26,534 --> 00:02:28,676
of working out where to send a user.

68
00:02:28,676 --> 00:02:30,346
In reality this method is just going

69
00:02:30,348 --> 00:02:32,376
to be dealing with http requests and

70
00:02:32,376 --> 00:02:34,080
http responses and that kind of thing.

71
00:02:34,080 --> 00:02:35,076
But we don't want to get bogged down

72
00:02:35,076 --> 00:02:36,540
with that because the principle is the same

73
00:02:36,540 --> 00:02:38,676
and indeed these two parameters using them and

74
00:02:38,676 --> 00:02:41,066
password could be annotated parameters which are bound

75
00:02:41,066 --> 00:02:43,274
to the controller upon servicing the web request.

76
00:02:43,274 --> 00:02:44,736
So don't worry about that for now.

77
00:02:44,736 --> 00:02:46,369
Just focus on the fact that the LoginController

78
00:02:46,369 --> 00:02:48,230
has one purpose and that one purpose.

79
00:02:48,230 --> 00:02:50,424
The thing it's supposed to know about, the thing it

80
00:02:50,424 --> 00:02:52,893
knows about that it's an expert and if you will,

81
00:02:52,893 --> 00:02:54,579
is to

82
00:02:54,579 --> 00:02:57,562
send the user to the home page

83
00:02:57,562 --> 00:03:01,681
or send the user to the login page. In

84
00:03:01,681 --> 00:03:04,104
other words, this class, this method specifically just

85
00:03:04,104 --> 00:03:06,444
knows about the home and the login pages and

86
00:03:06,444 --> 00:03:08,728
that's as it should do. Because the controller classes

87
00:03:08,728 --> 00:03:10,980
in the presentation there, so it doesn't know anything

88
00:03:10,980 --> 00:03:13,166
about how to actually authenticate a user and that's

89
00:03:13,166 --> 00:03:14,964
because to do so we need to actually start

90
00:03:14,964 --> 00:03:17,498
thinking about the layer underneath and that's the

91
00:03:17,498 --> 00:03:19,382
authentication service because the controller

92
00:03:19,382 --> 00:03:21,036
needs an authentication service to do

93
00:03:21,036 --> 00:03:22,476
its work as we'll see in the next video.

94
00:03:22,476 --> 00:03:24,218
So let's start flushing out the controller

95
00:03:24,218 --> 00:03:26,713
with the authentication service up next.