First ✈️

We need to make a new spring project the easiest way to do this is..... through .....

https://start.spring.io/

lets do a Maven Project this is the format we are going to use

Java

2.1.6

com.example you can change to edu.launchcode

Artifact -> your app name 

Dependencies 👽 I love these 

Lets grab 

H2 Database

Spring Web Starter

Spring Data JPA

Lombok 

Create the project

Next ❗️

Lets go ahead and open the project up in intellij

Now ⚜️

Lets go ahead and try to run it to make sure everything just checks out ok

Ok that should work 🍻

Now lets go ahead and set up the packages we are going to do to make this happen!

Packages 📦

Ok go into src/main/java/<whatever you named it>

at the same level as the main app class is where we want to create these packages for your classes

we need the following

model

repository

service

controller

Now we are getting really close to have this set up

First lets create a model class Labradoodle

This is represent a table in our H2 database

The @Data, @AllArgsConstructor, @NoArgsConstructor give us a constructor as well as setters and getters (lombok for the WIN 🙌🏻)

The @Table and @Entity are needed for JPA

@Data
@AllArgsConstructor
@NoArgsConstructor
@Table(name = "labradoodle")
@Entity
public class Labradoodle
{
    @Id
    @GeneratedValue
    @Column(name = "id")
    private Long id;

    @Column(name = "name")
    private String name;

    @Column(name = "owner")
    private String owner;
}

Now lets create the repository needed (its an interface)

This is used to communicate with the database its the main piece of Jpa at work here and as you can see its empty 😱

Check out the docs on this but it has method in the interface its extending so it all works out

@Repository
public interface LabradoodleRepository extends JpaRepository<Labradoodle, Long>
{
}

Now we need a service to add and get labradoodles

Notice the @Service and the other annotation

@Service
public class LabradoodleService {

    private LabradoodleRepository labradoodleRepository;


    public LabradoodleService(LabradoodleRepository labradoodleRepository)
    {
        this.labradoodleRepository = labradoodleRepository;
    }

    public List<Labradoodle> getAll()
    {
        return labradoodleRepository.findAll();
    }

    public Labradoodle addLabradoodle(Labradoodle labradoodle)
    {
        return labradoodleRepository.save(labradoodle);
    }
}

Ok the 🍞 and butter

Lets create our first rest end point

and then lets create our second 🤪

@RestController
@RequestMapping("/labradoodle")
public class LabradoodleController
{
    private LabradoodleService labradoodleService;

    public LabradoodleController(LabradoodleService labradoodleService)
    {
        this.labradoodleService = labradoodleService;
    }

    @GetMapping
    @ResponseStatus(HttpStatus.OK)
    public List<Labradoodle> getAll()
    {
        return labradoodleService.getAll();
    }

    @PostMapping("/new")
    @ResponseStatus(HttpStatus.OK)
    public Labradoodle addNew(@RequestBody Labradoodle labradoodle)
    {
        return labradoodleService.addLabradoodle(labradoodle);
    }
}

What are we doing here is saying that we have an endpoint that starts with /labradoodle that you can see at the top of the class.

Then we are setting up a getting mapping for the Labradoodle to get them all

Then we are allowing new labradoodles to be added through the /labradoodle/new end point.

Pretty neat 🤓

Now we need to set up the connections to H2

go to your src/main/resources/application.properties file

copy and paste this in

spring.h2.console.enabled=true
spring.h2.console.path=/h2-console
spring.datasource.url=jdbc:h2:~/liftoff-1;DB_CLOSE_ON_EXIT=TRUE
spring.datasource.username=sa
spring.datasource.password=

spring.datasource.platform=H2
server.port=8080

spring.datasource.driverClassName=org.h2.Driver

Sweet lets try to run it

You should be able to download postman to test it out

https://www.getpostman.com/downloads/

if you send a post to the following endpoint

http://localhost:8080/labradoodle/new

with this as the body (set it to be raw and change it from text to application/json)

this is the format for json

{
	"name": "Finn2",
	"owner": "Gavin222"
}

Its key value pairs

{
    key: value
}

It needs the " to make it proper json

Ok send that you should get back a response with whatever data you sent it if you changed my name for yours etc.

Ok now lets call a get request on

http://localhost:8080/labradoodle

We should get back our data

if you got stuck

here is the link to the repo with the code

https://github.com/gavinmeier25/liftoff-java-spring-service

What now?

Now you should be in a decent enough spot to be able to mess around with these things and have a flow in place that you can build from. If you get errors try to look at the errors stacktrace to see where it first occurs.