Getting Started

[MUSIC] 0:00 Hello and welcome. 0:04 I'm Craig, and I'm a developer. 0:06 In this course, we're going to build a RESTful API using Spring. 0:07 It's going to support HATEOAS, 0:11 or Hypermedia as the Engine of Application State. 0:13 It's gonna integrate with Spring data and Spring security, and 0:16 provide self-documenting schema generation, almost seamlessly. 0:19 Now, word of warning. 0:24 You're probably going to get your mind blown by how much you can do with such 0:25 little code, and that's the beauty of Spring Boot at work. 0:28 But, before we take off, 0:32 please take a moment to check out the teacher's notes and make sure that you've 0:33 completed the prerequisites, just to make sure we're talking the same language. 0:36 Don't forget to check the notes on each video. 0:40 I usually drop helpful hints, tricks, and knowledge nuggets down there for 0:42 your consumption. 0:46 And, always remember the speed controls. 0:47 Feel free to speed me up or slow me way down. 0:49 I don't mind at all. 0:53 So let's talk about the project that we're gonna build together. 0:54 Now first off, imagine, if you will, that we work on an international team 0:57 that produces applications as requested by clients, you know, like an agency. 1:01 So we have a very well established client who has come to us and 1:05 asked us to build a course review system. 1:09 They want a single-page application website, an iPhone and Android app, and 1:11 of course, they want it yesterday, and our sales team told them it'd be no problem. 1:15 So, here we go. 1:20 So first off, a course review system is reviewing online courses, you know, 1:22 like this one you're watching here. 1:25 It'll be used to gather public opinion on those courses, so 1:27 people can make an educated decision on what they should watch. 1:30 Our team huddled together and 1:33 decided that we should tackle building out all the prototypes at the same time. 1:34 The approach that we came up with to do this joint team rapid development 1:38 is to produce a REST API, that all clients, you know, 1:42 the site and the different phone and tablet apps can consume. 1:44 So you've landed on the API creation team, arguably, 1:47 the most important team on getting this project launched, so good job. 1:50 So together, 1:54 we're going to build an API that allows anyone to submit courses to it, then we'll 1:55 also allow anyone to add reviews about the courses that have been submitted. 1:59 So, for instance, if someone wanted to add a review 2:03 to this workshop that you're watching right now, they'd do something like this. 2:06 So we have the client let us know the title and the URL. 2:09 Our project manager, her name's Hannah, 2:11 has assured us that that should be enough to get us started. 2:14 And now that this course that you are currently watching exists already, 2:17 we could have people submit reviews to it. 2:20 Now I know you haven't seen this yet, so these probably won't make too much sense, 2:22 but here are some reviews it's gotten. 2:25 So this has a rating of four out of a possible five and 2:27 a more detailed description, and someone else submitted this one. 2:29 That's not how you pronounce HATEOAS! 2:33 Well, hatters gonna hat, I guess. 2:35 So side note, if you feel like you're having deja vu, don't worry, 2:37 you might have seen this project used in another one of our courses here on 2:40 Treehouse, on a different web framework. 2:43 We're producing several workshops and courses in various other frameworks so you 2:45 can compare and contrast their approaches to building the same end product. 2:49 So the relationship is one course to many reviews. 2:53 One to many. 2:57 We'll also add the ability to walk from the review back to the course. 2:59 So that's many to one, right, from the perspective of the review. 3:03 It's many reviews to one course. 3:06 Now not only will our resource endpoints support all the HTTP verbs, 3:09 it will also be hypermedia driven. 3:14 It will be HATEOAS compliant. 3:16 Again, that's the Hypermedia as the Engine of Application State. 3:18 It's gonna be discoverable. 3:21 Someone can make a request, and our API will produce a list of all of its defined 3:22 relationships so that it can see what other actions are possible and 3:27 make a new request to other related resources. 3:31 For instance, when looking at a specific review, 3:34 it would have a relation link back to the course resource. 3:36 Now with the skills that you've picked up thus far, you could definitely build 3:40 a Spring MVC application that took care of all of this, right? 3:43 For example, we could build out our CourseController, and then we'd write some 3:46 handlers, and we could have some code that respond to an HTTP getRequest 3:50 to the courses endpoint, which would return a list of all available courses. 3:56 Yeah, we'd also need to convert those Java objects to JSON, 3:59 or JavaScript Object Notation, you know, the standard, so 4:03 that our clients can consume them. 4:05 And we'd also add one that creates a new course when the courses collection 4:07 is posted to. 4:11 We'll have to parse the JSON that was sent in and there's plenty of great tools for 4:12 that, many embedded in the Spring framework. 4:16 Now, as you've probably experienced from working with Spring, 4:18 it's the framework that keeps on giving. 4:21 Since this is a pretty repetitive task, 4:23 there are a lot of tools in Spring that help ease these monotonous tasks. 4:25 For instance, 4:30 there's an annotation that allows you to mark a controller as a REST controller. 4:30 It is, as you might expect. 4:34 So now, by default, you can return domain objects and they will be converted to 4:36 JSON, using a tool included in your Spring installation called Jackson. 4:41 We'll take a look at that here in a bit. 4:45 So that's great, but still, those controllers are probably going to end up 4:47 looking a lot like each other, right? 4:50 I mean, just about every application you can think of would work 4:53 pretty much like this, wouldn't it? 4:55 List of stuff, get the details of the stuff, 4:57 add more stuff, add some stuff that's related to that stuff, delete some stuff. 4:59 Sure, why not. 5:03 That's pretty repetitive, and believe me, code like this actually exists, and 5:05 you'll encounter it all over the place in all sorts of frameworks. 5:09 REST API Creation is usually a repetitive error prone task, and 5:12 when you introduce the concept of resource linking, 5:15 it quickly starts to become overwhelming in complexity. 5:18 There's so much to remember! 5:22 What standard should I adhere to? 5:24 There's got to be a better way, right? 5:26 I mean, if it's all doing the same process, 5:28 which is basically just exposing your data model to a client in the same format, 5:30 why should we developers have to write that over and over again? 5:34 I mean, we have better stuff to do. 5:38 We've got to change the world with our awesome app. 5:39 Now, what if I told you that Spring developers agreed with that 5:41 thought process and created a way to make sure that you 5:44 actually don't even have to write the controller piece at all. 5:47 Wouldn't that be awesome? 5:50 Well you've come to the right workshop, my friend. 5:51 Sit tight, here it comes. 5:53