1
00:00:00,780 --> 00:00:06,420
Let's take a look at the mediator interface first, so we have two minutes here at college and send

2
00:00:06,420 --> 00:00:11,630
a message, send messages for sending the respective message to their respective user.

3
00:00:11,820 --> 00:00:19,780
But the ad will be important because we need to make sure that the mediator knows about the colonics,

4
00:00:19,800 --> 00:00:22,430
knows about all the users of the chat application.

5
00:00:23,190 --> 00:00:28,560
On the other hand, a colleague interface has two minutes to send and receive message.

6
00:00:28,600 --> 00:00:30,780
So these are pretty straightforward.

7
00:00:31,110 --> 00:00:35,450
The first one is used for sending the message and the other one for receiving it.

8
00:00:35,730 --> 00:00:42,210
The concrete mediator has a list of colleagues that is used for storing all the users of the chat application

9
00:00:42,970 --> 00:00:44,060
in the constructor.

10
00:00:44,070 --> 00:00:52,770
The list is instantiated to an array and as you can see, the ad will be used for adding those users

11
00:00:52,770 --> 00:00:55,030
of the application to this list.

12
00:00:55,290 --> 00:01:03,630
Also, this same message method will make sure that the message won't be received by the user that has

13
00:01:03,630 --> 00:01:06,960
sent the message, otherwise it won't be sent.

14
00:01:06,980 --> 00:01:14,280
So all the other colleagues, all the other users will receive the message that was sent by by end user.

15
00:01:14,700 --> 00:01:16,160
The concrete call.

16
00:01:16,170 --> 00:01:22,740
The class has mediator object and the name for for the respective user.

17
00:01:23,170 --> 00:01:30,210
As you can see, we instantiate those in the constructor to send a method here will output the name

18
00:01:30,210 --> 00:01:36,210
of the user that has sent the message and also the message itself and will call the mediator for sending

19
00:01:36,210 --> 00:01:42,960
the message from the perspective of this of this user and receive, as you can see, it will output

20
00:01:42,960 --> 00:01:50,760
only a system out print and then a message which will tell the name of the of the person of the user

21
00:01:50,940 --> 00:01:54,750
and also the message that was received.

22
00:01:55,530 --> 00:01:58,080
Let's take a look now at the main method.

23
00:01:58,080 --> 00:02:05,280
So here we instantiate the mediator we instantiate to a concrete mediator because this is the implementation

24
00:02:05,760 --> 00:02:13,200
of this interface and also calling one colleague to we give them a name and also we assign the mediator

25
00:02:13,200 --> 00:02:15,210
forum for both of these users.

26
00:02:15,870 --> 00:02:26,190
Then we add the two users to the mediators underlying areolas in order for it to to make it aware that

27
00:02:26,190 --> 00:02:28,850
there are two users in the application.

28
00:02:29,160 --> 00:02:34,590
And here we just send a message from the perspective of the user one.

29
00:02:34,980 --> 00:02:39,110
And this should be seen by all the users of the application.

30
00:02:39,120 --> 00:02:41,060
So let's see this in practice.

31
00:02:41,070 --> 00:02:42,780
Let's run this main method.

32
00:02:44,030 --> 00:02:51,290
So as you can see, the name of the person that has sent the message is is displayed here with with

33
00:02:51,320 --> 00:02:54,320
the content of the screen that contains the message.

34
00:02:54,530 --> 00:03:00,730
And also you can see that the other participants in the chat received the message.

35
00:03:01,010 --> 00:03:03,860
So this is the implementation of this pattern.

36
00:03:04,550 --> 00:03:10,640
As you can see, the objects are not communicating between each other, but they are relying on an external

37
00:03:10,640 --> 00:03:13,940
object on a mediator to mediate the dialogue between them.

38
00:03:14,090 --> 00:03:22,190
So this can be very, very useful in situations when you have multiple, multiple objects that are communicating

39
00:03:22,190 --> 00:03:22,830
with each other.

40
00:03:23,000 --> 00:03:31,370
So instead of having a very, very complex scenario where you have to exchange various messages between

41
00:03:31,370 --> 00:03:36,830
various objects, you just send those messages to a mediator and the mediator will take care of the

42
00:03:36,830 --> 00:03:40,090
message and we'll send it to the relevant colleague.

43
00:03:41,300 --> 00:03:43,280
So that's it for this tutorial.

44
00:03:43,790 --> 00:03:45,020
Join me in the next one.

45
00:03:45,140 --> 00:03:47,750
We are going to discuss about the momento pattern.