Welcome to Amigos Code.

My name is Nelson.

And in this crash course, I'm gonna teach you everything you need to know about Spring Spring.

But it's an amazing framework for building Java applications very fast.

Recently, Netflix just announced that they will be switching their entire back end to spring book.

And this is because bring boo is so solid that there's no need for you to reinvent the wheel so they provide things such as connected to two databases jetty, servers, metrics, configuration and privileges Review.

Having to configure the low level code to get up and running, you can simply use spring book and get off the ground very quick.

So first I'm gonna show you exactly how to do Sprinkle the prentiss injection and how to implement to an interface where we will have any memory database.

And then I'm gonna show you exactly how to connect to a real database running on Docker.

So went out further ado.

Let's get started.

All right, amigos.

Welcome to amigos code in this video on a teacher Exactly how to use spring put 2.0, Spring bow is by far one of the best frameworks for building applications in the Java world.

So you gonna build an enterprise application?

You can use spring book or if you want to prototype on idea and see whether on and, you know, it works that you can use spring but because it makes it very easy toe build applications and basically springboard provides you a platform for building back and applications and on Lee that you can also build Web applications as well.

So in this video, let's go ahead and build this awesome A p I where any clients can submit a request.

So these requests could be a get request post the lead and put.

And then we're gonna take that request and within the AP, I layer or control layer.

So this is where we received the requests.

We're gonna send that to the service layer, and basically, the service layer is responsible to handle all the business logic that you may have within your application.

After you perform some business logic, then you might decide to use a database to perform some various current operations and basically so this layer right here so this layer is responsible to connect tow any database off your choice So the coating about spring book on Depends injection is that you can start with an implementation.

And then if you want to switch to a different database, you simply have to change one line of code, and I'm gonna show you exactly how to do that with the pendency injection.

So after you submit the actual request from any clients of the clients could be an IOS app, a react, or even an 100 up.

The request will go through all these layers and then go back with a response to the client.

So the response could actually be, for example, a Jason payload or an image or a status code off 205 100 so on and so forth.

So if you know, land the best framework for building job applications, stick to this video because there is a lot to cover.

And I'm pretty sure that after this video you will be very comfortable building back and applications with Sprinkles.

So let's go ahead and get started.

So the very first thing that I want you to do is to navigate to this website started spring.

Though I owe and basically this website, you can see that it's its title.

Spring initialize er it basically allows you to Butch trap your application by picking dependencies and configuring the actual project.

So go ahead and generate a project with maven.

We can see that it could be great.

It'll and then you have the option to code with Java chortling all groovy.

So I'm gonna sit with Java and then for the actual version, make sure that it is above two point.

Oh, so I've got a video on 1.5, and basically I just wanna make sure that you guys have the latest version so that you can use it within your latest projects.

So then go ahead and click on this link right here, So switch to the full version basically right here You can configure your project matter data, so go ahead and change these according to your company or project name.

But for this tutorial, I'm gonna leave everything as is apart from the Java version.

So I'm gonna pick driver 11 because I do have installed.

But if you don't have to have 11 and go ahead and pick Java eight because it will also work, then if it's called down you can see that right here.

We have a bunch off the penance ease.

And this is why springboard is pretty much one of the best job of frameworks for building applications.

So they give you a lot of flexibility with these appendices, which simply means that you can install one of these appendices and start coding right away instead of you having to configuring and, you know, setting up things.

So, basically, you just have to install these dependencies and then start implementing whatever you want, so you can see that they have a bunch of sections right here.

So web.

So service Web applications with spring envision Tomcat, Jersey Web sockets, template engines, security.

So they make it very easy for you to configure security within your applications.

So you know, it saves you the hassle of having to implement security that right ways.

So basically, they're doing the difficult job, which is implementing the security and and then giving you this nice package that you can just plug and play.

And then you have SQL.

So my sequel, a studio, BBC, post grass, fly away for database migrations, mongo.

And then you can scroll down.

You could see that they have a lot of great things.

So for this video right here, let's go ahead and focus on picking this dependency right here.

So Web server, web applications, wheat springing greasy on Tomcat so much that and then generate a project.

So right here you see the off court, this demo zip, which I'm gonna open in my desktop.

There we go.

So now I'm going to quick on this zip folder.

And if I the late the actual zip, you can see that now I have this folder right here.

So for this video, I'm gonna be easy intelligent, which is by far the best i d.

And if you want to learn about intelligent, go ahead and check my video on YouTube, which I show you how to download, install and configure intelligent it properly.

And if you are using net beans or eclipse, this will also work.

So insider Intel A J.

So I actually recommended to download and install intelligent if you don't have it to follow along.

And I'm pretty sure that you're gonna learn great things with intelligent throughout this video.

So what I'm gonna do now is pray much click on, open and then navigate.

Would that stop and then open up this damn a folder and then open up the actual palm thought XML So I'm gonna open that up and then open ice project, so I'm gonna allow and just keep a second maven A's resolve indeed.

Appendices for this project.

There we go.

So that's nice and done.

So let's go ahead and explore this project.

So open up demo and inside them or you can see they have couple of folders.

But the ones that we really care about are the palm dot xml So if I open it up and see that this is what you saw when configuring the project with spring initialize er so you saw the group I D artifact, um, name and then version.

So this is the version right here.

And then this is job 11.

Basically, the actual dependency that we picked was this one right here.

So springboard start a web, and by default springboards ships with spring ball started test for writing unit on integration tests.

So go ahead and close this because we don't need it and open up the source folder so open up, source and then Maine, and you can see that you have a job, and then inside you should have a, um, class called demo application.

And inside of this glass, you have this public static void main method.

And this is how you pretty much just run your spring application.

And if I play so make sure you play this, Just give me a second.

You should see that I have spring up and running and you can see that it say that tomcat started on poor 80 80.

So right here, we could change the sport.

But this is a D for port for Tomcat.

So I'm gonna stop this, and you can see that everything is up and running.

Fine.

Come on, stop this and then collapse this And then inside of resources, you have static templates and application that properties.

So static is where all the web resources live for Web applications, and then you have templates.

And this is where you have all the templates for your wear application.

So usually you would use something like most ash or E j s.

And then you have this application that properties.

So this is where all the properties for your application do live.

And the coating about properties is that you can define properties for different environments, so you could have a demo environment, a test environment and a production environment with different values for the actual properties.

So it's pretty cool.

So I'm gonna counsel out of that.

And now that you know the actual structure and make sure that you can start the application, you've successfully managed to start a Tomcat server with spring book.

So now let's go ahead and implement our A p I with all of those resources controllers Service's and finding a database as well.

So if I go back to this diagram, so remember that I said we had the AP layer controller or control that layer and then we have a service later for business logic and then database for data access.

So let's go ahead and start things right here.

So we're gonna start right here, and in fact, let me put a dot right here so you know what we're doing.

So if I remove that, basically, let's put just a dot so we know where we are, um, with things.

So right here and then if I collapsed That So basically, we're going to implement this section first and then move our way up.

So basically, we're going to implement one step at the time and then see everything working, fine, and then implement some other functionality.

So let's go ahead and go back to intelligently.

And the first thing that I want you to do is to create a MME a package.

So let's go and create package and right here simply call it a P I.

So this is where the FBI will live.

Go ahead and create a second package and simply say model.

Go ahead and create 1/3 package.

Call it service.

Go ahead and create 1/5 package, actually, fourth package and call it so we need the actual d A.

L.

And I think this is it.

So we have a B i D e o model and service.

And basically these packages are representing this diagram.

So if I go back and perhaps you haven't seen me, like right clicking so new and then package.

So basically, I tend to use a lot of keeper shortcuts and this is how I am productive with intelligent.

So if I press control and then enter.

You can see the keyboard shortcut down below, and basically, then that gives me the ability to create a new package.

So the same if I'm, for example, create a variable.

So if I say far and then a low equals to two, um and then if I press command and then why you can see the keyboard down below?

Right, So I've just deleted that line.

So also, let me go ahead and say, OK, so now what we need to do is actually the fine our model.

So what is the actual model for this application?

So if I go back to this diagram so it's going and define a model, someone copy this stereotype and you can grab this diagram, you can find a link in the description below.

We can download and see exactly you know, everything that we're doing here.

So basically the actual model soaps.

So the model for this, um, tutorial will be a person, and basically a person will have an i D.

So when I d and let's keep things simple and half like, let's say fool.

Oh, actually name just like that.

So obviously you could have more properties, but I want to keep it simple.

So you see exactly what's happening.

And so things you know become really obvious to you.

So we have this model right here called person.

Let's go ahead and define this in actual quote.

So go back to intelligence and inside off the model package.

Go ahead and create in your class and simply call this person, right?

So the kind it's a class and then press enter.

So now simply go ahead and say private final, and then the i d will be off, type you it and simply call the I d.

Go ahead into Pacific private final and then string.

So this is the actual name, and then I'm gonna add these two instructors.

You can see I'm using keyboard shortcuts again, and then the getters.

So just like that, and there we go.

So now we have a model that we can work with.

So if I go back, so now we have to define the actual database section right here, right?

So let's define the actual interface that will allow us to have any implementation for our database.

So inside of the d A.

Oh, go ahead and create a class and then simply say person and then d A.

O So instead of a class changed this to an interface, and this is the actual interface where we're going to define the operations allowed, or the actual contract for anyone that wishes to implement this interface and the quilting about it is that we can then use the penance injection to switch between implementations with just one line of code.

So let's go ahead and define our very first method.

So for our database, we want toe insert a person into the actual database, so we will simply return an integer.

And basically we're gonna mark a database using like, a list.

And basically we will return zero or one, depending whether the actual data is persisted to the actual database.

So let's simply go ahead and say, insert and then person, and this will take you it, which is the actual I d.

And then a person just like that, and then end up with semi column.

Now let's also go ahead and create a default, um, method and basically this will be the same thing.

Actually.

Sorry.

This will be integer so will be the same thing.

And listen, we call this ad and then person and right here we will simply take person.

Right.

And what this allows us to do is to actually generate the Hewitt's ourselves or the actual i d.

So you would.

And then let's call it I d equals two, and then you it don't and then run them.