WEBVTT 00:00.110 --> 00:00.650 Hi everyone. 00:00.650 --> 00:01.190 Welcome back. 00:01.190 --> 00:06.740 In this lecture we are going to learn about how to have another module reference a code from module 00:06.740 --> 00:07.040 one. 00:07.040 --> 00:12.020 So in this case we are going to use module two which is going to be referencing the module one service 00:12.020 --> 00:17.120 class by adding this project which is module one as a dependency to the module two. 00:17.150 --> 00:21.260 So in this case let's go ahead and open the module two Build.gradle file. 00:21.260 --> 00:24.020 So this is a build.gradle file for module two. 00:24.050 --> 00:25.700 So in this case we are going to be. 00:25.730 --> 00:28.130 You might notice this code also in your project. 00:28.130 --> 00:29.390 So let's uncomment this one. 00:29.390 --> 00:34.820 So what we are trying to do is we are trying to add the module one as a dependency to the module two, 00:34.850 --> 00:38.360 so that we get to access the source code from module one. 00:38.390 --> 00:43.730 So think of this as a client library which is going to use some of the code from module one. 00:43.730 --> 00:48.920 So now what I'm going to do I'm going to build a client package in the module two and try to reference 00:48.920 --> 00:51.020 the module one service from it. 00:51.050 --> 00:51.410 Okay. 00:51.440 --> 00:54.050 So here we are going to create a package. 00:54.080 --> 00:56.510 The package name is going to be client. 00:56.510 --> 01:01.250 And then I'm going to name this client class as module one client okay. 01:01.280 --> 01:07.560 Module one client, and in the module one client, I'm going to reference a module one service because 01:07.560 --> 01:09.090 I added this as a dependency. 01:09.090 --> 01:12.210 So I expect this module one service to be visible. 01:12.210 --> 01:21.960 So in this case let's go ahead and add private final module one service and module one service okay 01:21.990 --> 01:25.650 so I added this but still I have some compilation issues going on. 01:25.650 --> 01:28.200 Let's mouse over on that one add constructor parameter. 01:28.230 --> 01:28.860 There you go. 01:28.860 --> 01:30.480 So this code works as expected. 01:30.480 --> 01:33.540 What I'm going to do I'm going to introduce a function similar to this one. 01:33.570 --> 01:37.950 So in this case let's copy this function and then add it over here. 01:38.010 --> 01:40.890 But this function is not going to return the module directly. 01:40.920 --> 01:45.960 This is going to be using the module one service and call that specific function. 01:45.960 --> 01:49.290 So module one service dot retrieve data okay. 01:49.320 --> 01:50.970 And then add the semicolon over here. 01:50.970 --> 01:53.670 So this works as expected without any issues. 01:53.670 --> 02:00.060 So what we did so far is that we added a modular project into our project which doesn't use any modules 02:00.060 --> 02:00.720 concept. 02:00.720 --> 02:06.460 If you're using a setup like this, your code still gets executed in a module named Unnamed Module. 02:06.460 --> 02:11.110 I'll cover that in the future part of the section, but for now, what I'm going to do is I'm going 02:11.110 --> 02:17.200 to make this module two also to be modular and then show you the difference in the behavior. 02:17.200 --> 02:20.620 So what I'm going to do I need to create another module info file. 02:20.620 --> 02:22.750 So right click on this Java directory. 02:22.750 --> 02:25.210 So I'm in module two right now click on the file. 02:25.240 --> 02:29.920 It's going to be module hyphen info dot Java okay. 02:29.950 --> 02:34.000 So we can use that module info that we created from module one as a reference here. 02:34.000 --> 02:35.890 So in this case I'm going to put it on the right. 02:36.220 --> 02:36.940 There we go. 02:36.940 --> 02:41.560 And then what I'm going to do I'm going to create something similar. 02:41.560 --> 02:45.430 But in the case of this one this is going to be module two okay. 02:45.460 --> 02:47.470 So I'm going to remove all these things. 02:47.470 --> 02:50.290 It doesn't require any HTTP module two. 02:50.320 --> 02:52.690 So in this case after adding this right. 02:52.690 --> 02:55.870 So now let's go ahead and take a look at the module one client. 02:55.870 --> 03:00.520 So as soon as I go into the module one client I have issues over here. 03:00.520 --> 03:01.840 So what is the issue. 03:01.870 --> 03:09.330 It says like package comm dot module one dot service is declared in module module one, but module module 03:09.360 --> 03:10.950 two does not read it. 03:10.950 --> 03:16.770 So it is asking us to add the requires module one directive to the module-info.java file. 03:16.770 --> 03:18.690 In this case I'm going to add that one. 03:18.690 --> 03:19.920 So when I add that. 03:19.920 --> 03:25.290 Now if you go to the module info file which is part of the module two, you'll be able to see that requires 03:25.290 --> 03:25.710 directory. 03:25.710 --> 03:28.050 So as soon as you add this requires directive. 03:28.080 --> 03:30.720 This particular package gets resolved. 03:30.750 --> 03:37.170 Now the next thing is the module one also has something called secret something called HTTP client. 03:37.200 --> 03:37.800 Right. 03:37.800 --> 03:40.020 But these are not part of the exports. 03:40.020 --> 03:42.030 That is part of the module info file. 03:42.030 --> 03:43.680 That is part of module one. 03:43.680 --> 03:46.560 So in this case we are just exporting these two packages right. 03:46.560 --> 03:48.810 So what will happen if you try to access it. 03:48.810 --> 03:51.660 So in this case I'm going to open the module one client. 03:51.660 --> 03:57.270 And in this client I'm going to try to add the secret class in this case private secret. 03:57.270 --> 04:03.450 If you type secret there is no reference of that one because we are not even exporting that specific 04:03.450 --> 04:05.490 class as part of the module one. 04:05.490 --> 04:08.560 So now let's say if I go ahead and add that right. 04:08.590 --> 04:11.590 So in this case, if we add the secret package what will happen? 04:11.620 --> 04:15.820 So as soon as I add the secret package you'll be able to see that it is going to resolve. 04:15.820 --> 04:16.180 Fine. 04:16.210 --> 04:16.510 You see. 04:16.540 --> 04:16.810 Right. 04:16.810 --> 04:19.870 I'm able to get access to that secret package. 04:19.870 --> 04:22.240 So this is a behavior of exports. 04:22.240 --> 04:24.190 So now I'm going to remove the secret. 04:24.190 --> 04:27.460 And then you'll start to see the compilation issues showing up. 04:27.760 --> 04:30.040 So let's go ahead and remove the secret from here. 04:30.040 --> 04:33.190 So this is the advantage of using the modules concept. 04:33.190 --> 04:38.710 So you have complete control on what kind of packages you want to export and what kind of packages you 04:38.710 --> 04:40.060 don't want to export. 04:40.090 --> 04:40.450 Okay. 04:40.480 --> 04:48.040 So this is how you connect to different modules together using the Jpms concepts, which is also called 04:48.040 --> 04:49.210 modules concept. 04:49.210 --> 04:54.220 So we have created module one module file and module two module file. 04:54.220 --> 04:59.560 And this particular module specifically just uses a module one and implements this logic. 04:59.560 --> 05:03.190 So this is how you connect to modular projects. 05:03.220 --> 05:06.670 If you want to reference one code from the other module. 05:06.700 --> 05:08.260 This marks the end of this lecture. 05:08.260 --> 05:09.310 Thank you for watching.