WEBVTT 0 00:01.450 --> 00:02.530 Hey, in this video, 1 00:02.530 --> 00:05.163 we're going to find out why should we use Spring. 2 00:07.900 --> 00:09.930 So, Spring in a nutshell. 3 00:09.930 --> 00:12.450 Basically, Spring is a very popular framework 4 00:12.450 --> 00:15.630 for building enterprise Java applications. 5 00:15.630 --> 00:16.960 When Spring first came out, 6 00:16.960 --> 00:21.510 it was initially a simpler, lightweight alternative to J2EE. 7 00:21.510 --> 00:24.440 They basically give you a large number of helper classes 8 00:24.440 --> 00:26.913 to make enterprise development easier. 9 00:28.810 --> 00:32.980 But now, you may wonder, well, what about J2EE or Java EE? 10 00:32.980 --> 00:35.960 And here, they have client-side presentation, 11 00:35.960 --> 00:38.040 they talked about server-side presentation 12 00:38.040 --> 00:41.640 with JSP, servlets, XML, and Web Services. 13 00:41.640 --> 00:44.640 They also discussed the idea of server-side business logic 14 00:44.640 --> 00:48.380 using Enterprise JavaBeans, Web Services, and so on. 15 00:48.380 --> 00:50.970 And all talk into a backend database. 16 00:50.970 --> 00:52.880 And this all looks really good on paper 17 00:52.880 --> 00:54.220 and as the developers, 18 00:54.220 --> 00:58.280 we were very excited when we saw this, viewing it on paper, 19 00:58.280 --> 00:59.790 but what happened is that when we actually got 20 00:59.790 --> 01:02.980 into the implementation details, it was another story, 21 01:02.980 --> 01:05.080 and I'll talk more about that in a second. 22 01:07.600 --> 01:09.750 All right, so how did J2EE grow up? 23 01:09.750 --> 01:11.920 Well, in the early days, it started out really nice. 24 01:11.920 --> 01:14.930 You had servlets, JSPs back in 1999. 25 01:14.930 --> 01:18.070 You also had Enterprise JavaBeans, Java Message Service, 26 01:18.070 --> 01:20.130 and RMI, Remote Method Invocation. 27 01:20.130 --> 01:20.963 And then over the years, 28 01:20.963 --> 01:24.050 they added more support for EJB with 1.3. 29 01:24.050 --> 01:28.212 They added, in J2EE 1.4, they added Web Services. 30 01:28.212 --> 01:31.200 In Java EE 5, they kind of renamed it a bit, 31 01:31.200 --> 01:33.020 so it's Java Enterprise Edition 5. 32 01:33.020 --> 01:35.070 They dropped the J2EE thing. 33 01:35.070 --> 01:37.603 And then they added some ease of use for EJB 3, 34 01:38.721 --> 01:42.920 JPA, JSF, JAXB, and JAX-WS or Web Services. 35 01:42.920 --> 01:45.450 And then with EE 6 again, they pruned, 36 01:45.450 --> 01:48.330 meaning they got rid of some stuff that didn't work, 37 01:48.330 --> 01:51.000 mainly some of the EJB problems, 38 01:51.000 --> 01:54.160 and also, they made it easier to use so on and so forth. 39 01:54.160 --> 01:58.173 They had a support for CDI, Context Dependency Injection. 40 01:59.720 --> 02:01.390 And then finally, in Java EE 7, 41 02:01.390 --> 02:03.940 they added support for JMS version two, 42 02:03.940 --> 02:07.490 Batch, Concurrency, Web Sockets, and so on. 43 02:07.490 --> 02:10.920 So, that's kind of how J2EE grew up over time. 44 02:10.920 --> 02:15.100 So, servlets and JSPs were like the initial popular items 45 02:15.100 --> 02:18.193 and then they started adding other things along the way. 46 02:20.200 --> 02:22.040 Now, the one thing they added along the way 47 02:22.040 --> 02:23.980 was Enterprise JavaBeans. 48 02:23.980 --> 02:26.670 And so, EJB is like your cousin 49 02:26.670 --> 02:29.120 or your family member that you just don't really like 50 02:29.120 --> 02:31.740 because they just mess things up for everybody. 51 02:31.740 --> 02:35.290 So, the early versions of Enterprise JavaBeans, 52 02:35.290 --> 02:39.410 versions one and two, were extremely complexly developed. 53 02:39.410 --> 02:43.070 You had to create these XML deployment descriptors. 54 02:43.070 --> 02:46.060 You had to define multiple interfaces. 55 02:46.060 --> 02:48.220 So, like we have on this diagram here, 56 02:48.220 --> 02:52.150 to create a Bean Class, we had to have a Home Interface 57 02:52.150 --> 02:53.990 and then a Component Interface, 58 02:53.990 --> 02:57.200 and you basically had, like, three or three .java files 59 02:57.200 --> 03:00.380 just for an actual Bean implementation. 60 03:00.380 --> 03:01.650 So, just a lot of work. 61 03:01.650 --> 03:03.830 It was really clunky for a developer 62 03:03.830 --> 03:05.850 to write all of this code. 63 03:05.850 --> 03:08.390 It was very tedious and very error prone. 64 03:08.390 --> 03:10.710 But once you've finally got the Bean developed 65 03:10.710 --> 03:13.730 and deployed it, and you deployed it in production, 66 03:13.730 --> 03:17.830 then you are slapped with another problem: poor performance. 67 03:17.830 --> 03:19.690 So, these Entity Beans, 68 03:19.690 --> 03:23.210 basically mappings between Java classes and database tables, 69 03:23.210 --> 03:25.970 ah, just awful slow, just terribly slow. 70 03:25.970 --> 03:27.570 Like, we actually had to do, 71 03:27.570 --> 03:31.460 on one deployment, we actually had to pull our code 72 03:31.460 --> 03:33.300 back out of the production 73 03:33.300 --> 03:35.590 and actually remove the EJB functionality 74 03:35.590 --> 03:38.260 because it slowed everything down. 75 03:38.260 --> 03:41.260 And so, what happened over time is that a lot of developers 76 03:41.260 --> 03:44.500 started to continue to do J2EE 77 03:44.500 --> 03:48.403 but they actually would do it without Enterprise JavaBeans. 78 03:49.650 --> 03:50.860 And so, this kind of caught on 79 03:50.860 --> 03:52.680 with other development teams too 80 03:52.680 --> 03:55.000 and pretty much, a lot of folks are doing it. 81 03:55.000 --> 03:56.960 So, this one fellow, Rod Johnson, 82 03:56.960 --> 03:58.250 he actually wrote this great book 83 03:58.250 --> 04:02.350 called J2EE Development without EJB. 84 04:02.350 --> 04:04.320 So, EJB was very popular at one point, 85 04:04.320 --> 04:06.010 then it fell out of favor. 86 04:06.010 --> 04:07.420 And so, he pushed that out 87 04:07.420 --> 04:09.840 and they also started working on the Spring Framework. 88 04:09.840 --> 04:11.810 And so, they released another book, 89 04:11.810 --> 04:15.180 Java Development with the Spring Framework. 90 04:15.180 --> 04:17.980 So, EJB was kind of like that bad cousin 91 04:17.980 --> 04:20.110 or that bad uncle that you just didn't want in the family 92 04:20.110 --> 04:23.943 because they mess it up for everybody.