WEBVTT 00:00.720 --> 00:01.230 Hi everyone. 00:01.230 --> 00:02.460 Welcome back to this tutorial. 00:02.460 --> 00:08.190 In this tutorial we will code and explore the counting Collector as part of this tutorial. 00:09.410 --> 00:16.760 The name counting collector returns the total number of elements the collector collected as a result. 00:17.030 --> 00:18.470 Let's go ahead and explore this. 00:19.320 --> 00:21.120 Using our example app. 00:21.150 --> 00:23.820 Then you open here what I'm going to do. 00:23.850 --> 00:30.420 I'm going to create a class called Streams Counting example. 00:31.860 --> 00:39.390 Make this class executable by adding public static void main method and then put this in presentation 00:39.390 --> 00:39.960 mode. 00:39.990 --> 00:45.480 So here what I'm going to do, I'm going to create a method called public static. 00:45.510 --> 00:52.800 The counting method returns a type long and then I'm going to name this one as count. 00:53.580 --> 01:00.030 The first call that I'm going to make is student database dot get all students. 01:00.270 --> 01:02.460 The next one is let's call the stream method. 01:03.620 --> 01:08.260 Want to give us a stream of students for us and then we're going to use the collect. 01:09.440 --> 01:11.180 And we are going to use counting. 01:13.220 --> 01:17.030 Basically, we have to do a static import of counting. 01:17.510 --> 01:18.270 There you go. 01:18.290 --> 01:19.610 Collectors dot counting. 01:20.600 --> 01:21.920 We do a return. 01:23.060 --> 01:28.340 This is going to return total number of elements that reach the collect method. 01:28.790 --> 01:32.510 But we are we know by now here we don't have any conditions. 01:32.510 --> 01:37.910 Whatever the values that are written here, whatever the number of students that are returned here will 01:37.910 --> 01:40.050 be, the value that the count is going to return. 01:40.070 --> 01:42.620 You might be wondering, okay, there is no special case. 01:42.620 --> 01:47.180 I can do that by using the get all student dot size that is going to do the same, Right? 01:47.180 --> 01:53.210 But we can add some enhancements to it so that it will make more sense on scenarios when you can use 01:53.210 --> 01:53.930 counting. 01:54.920 --> 01:56.600 So I'm going to print this. 01:57.110 --> 02:00.620 Let's call this count method run. 02:00.620 --> 02:08.690 This is going to give me the result as six because the get all student has a total of six students. 02:08.990 --> 02:11.330 Now let's enhance this use case. 02:11.540 --> 02:12.890 How can we enhance this? 02:13.100 --> 02:18.950 Let's say I want to filter the students by their GPA. 02:19.370 --> 02:21.060 Student dot. 02:21.060 --> 02:22.380 Student dot. 02:22.890 --> 02:25.890 Get GPA greater than or equal to 3.9. 02:26.040 --> 02:33.030 The students who are as the GPA greater than 3.9 are the students, which will cross this filter layer 02:33.030 --> 02:35.340 and reach the collect method. 02:35.520 --> 02:41.140 Let's run this example and then check what is the result of the count method. 02:41.160 --> 02:42.150 The result is three. 02:42.180 --> 02:45.710 So under what scenarios you might use counting. 02:45.720 --> 02:48.030 Let's say you have a use case you want to check. 02:48.360 --> 02:51.240 You have this many number of elements. 02:52.060 --> 02:55.510 Filter this many number of elements matching this criteria. 02:55.510 --> 02:59.320 In those kind of scenarios, you can use the counting method. 03:00.480 --> 03:03.240 So this is all about the counting collector method. 03:03.270 --> 03:05.350 With this, we came to the end of this tutorial. 03:05.370 --> 03:06.390 Thank you for watching.