1 00:00:01,630 --> 00:00:08,530 In this step, let's look at my favorite feature. The application is up and running and I would be making a change 2 00:00:08,530 --> 00:00:13,420 here. So I'm changing the mastering spring 5.0 to 5.1. 3 00:00:13,600 --> 00:00:15,940 What would happen, when I execute the service? 4 00:00:15,940 --> 00:00:18,770 The service is still returning 5.0. 5 00:00:18,840 --> 00:00:26,560 The service does not pick the change up because to pick up the change I would need to stop the server and restart 6 00:00:26,620 --> 00:00:29,940 it again. And that's cumbersome, isn't it? 7 00:00:29,950 --> 00:00:30,740 Starting up the 8 00:00:30,760 --> 00:00:33,480 server would take a few steps. 9 00:00:33,490 --> 00:00:38,010 I meanit would take a few seconds and that would waste my time. 10 00:00:38,050 --> 00:00:44,350 How can I get the whole thing to be loaded automatically as soon as I make a code change? 11 00:00:44,380 --> 00:00:45,450 How do I do that? 12 00:00:45,670 --> 00:00:46,300 That's where 13 00:00:46,390 --> 00:00:49,580 Spring Boot developer tools come in. 14 00:00:49,640 --> 00:00:51,730 It's an awesome dependency. 15 00:00:51,730 --> 00:00:52,870 I love it. 16 00:00:52,910 --> 00:01:03,210 I'll copy spring boot starter actuator and I'll put it below test. Spring Boot, it's called spring boot 17 00:01:03,380 --> 00:01:05,310 dev tools. 18 00:01:05,620 --> 00:01:09,060 I just added our dependency on to spring boot dev tools. 19 00:01:09,140 --> 00:01:10,620 It's as simple as that. 20 00:01:11,000 --> 00:01:18,420 I'll wait the whole thing to build. So you can see that it's downloading that dependencies. The project is redthe project 21 00:01:18,430 --> 00:01:23,180 is ready and now I execute it. When I start the server, 22 00:01:23,230 --> 00:01:29,460 You can see that the server is loaded or server started. And now as you did I would get 5.2 23 00:01:29,470 --> 00:01:33,120 obviously because I've restarted the server. But 24 00:01:33,160 --> 00:01:39,960 the great thing from now on is any Java changes that you make would be automatically picke up. So I'm 25 00:01:40,000 --> 00:01:44,490 going back to 5.0. What would happen if I execute this? 26 00:01:44,530 --> 00:01:51,190 One of the things you would see in the logs is that the application is restarting automatically and 5.0 27 00:01:51,550 --> 00:01:54,200 This time let's focus on what's happening in the log. 28 00:01:54,370 --> 00:01:58,310 I'll just clear off whatever log is there. And I'm making a change. 29 00:01:58,450 --> 00:01:59,410 Mastering spring. 30 00:01:59,410 --> 00:02:00,570 5.1. 31 00:02:00,620 --> 00:02:08,920 Let's say. 5.1 is not yet here at the time of creating this video but just having fun. So you can 32 00:02:08,920 --> 00:02:14,520 see that this specific thing is also very efficient at the way it restarts. 33 00:02:14,620 --> 00:02:17,890 You can see that this actually started in two seconds. 34 00:02:17,890 --> 00:02:25,570 The change was picked up in two seconds. I'll stop the application and restart it. 35 00:02:25,680 --> 00:02:33,580 You would see that actually the typical restart when I do a fresh restart on spring boot is about 8 to 36 00:02:33,580 --> 00:02:35,010 10 seconds. 37 00:02:35,050 --> 00:02:40,560 So this is taking about 9 seconds. So if I stop and restart the application it's taking about 9 seconds. 38 00:02:40,780 --> 00:02:50,320 However, if I just make a change directly here. I'llwhat I'll do. actually turn this off. And also let's look at how much 39 00:02:50,320 --> 00:02:51,980 time it takes. So now 40 00:02:52,060 --> 00:02:53,970 how much time did it take? 41 00:02:54,070 --> 00:02:57,340 You can see that this actually takes two and a half seconds. 42 00:02:57,340 --> 00:02:58,690 Pretty cool! Isn't it? 43 00:02:58,690 --> 00:03:03,850 So one of the things that Spring Boot does, Spring Boot dev tools does very effectively, 44 00:03:03,850 --> 00:03:10,780 is it knows that everything in Maven dependencies will not change at all. So it will not load things which 45 00:03:10,780 --> 00:03:17,530 are dependent on these again. It will only load those beans which arewhich are the application beans 46 00:03:17,570 --> 00:03:19,760 again. That's why it takes lesser time 47 00:03:19,810 --> 00:03:25,340 when you make a change. When you restart the server, everything including whatever is in here is loaded 48 00:03:25,600 --> 00:03:32,440 but when you when you make a change in the application only that specific things which are application 49 00:03:32,440 --> 00:03:39,310 related are reloaded again. And that's the reason why you see that it only takes 2 seconds and imagine 50 00:03:39,640 --> 00:03:43,050 the amount of productivity you would gain with this. 51 00:03:43,180 --> 00:03:47,920 So this is almost 10 seconds saved for every change you make. 52 00:03:47,980 --> 00:03:53,920 If you are maintaining any kind of application that's a big productivity boost. So if you are using a Spring 53 00:03:53,920 --> 00:03:59,680 Boot application and if you are not using to Spring Boot developer tools then go ahead and try it. 54 00:03:59,730 --> 00:04:06,370 That's a pretty cool addition, I would think, to Spring Boot. In the step, we looked at Spring Boot dev tools which 55 00:04:06,370 --> 00:04:10,780 is one of my favorite additions to Spring Boot. Until the next video, bye-bye.