PersonController.CRUD

CRUDApplication

This repository provides a starter project for a CRUD application using Spring Boot, RestControllers, and H2 for an in memory database. When using the H2 console in the browser (eg: localhost:8080/console) be sure to set the JDBC URL to match the url defined in application-h2.properties. The default is jdbc:h2:mem:testdb.

Exercise

Using this project as a starter, you will create a Person class as an entity to persist to H2 with an autogenerated id, and provide access to CRUD operations on those entities using a Spring Rest Controller supporting GET, PUT, POST, and DELETE operations. Spring Boot will handle the actual HTTP traffic and database components for you, you just need to build the last few pieces of the puzzle described in this lab.

As you are working on this lab, you can demo the behavior of your GET endpoints using your browser. For PUT, POST, and DELETE you will need a more robust tool, such as Postman or curl.

Part 1:

Create a Person class with fields for first name, last name, and an id number.

Create a PersonController class with Person createPerson(Person p), Person getPerson(int id), List<Person> getPersonList(), Person updatePerson(Person p), and void DeletePerson(int id) methods, and let it track a list of Person objects.

Add the @RestController annotation to your PersonController class, and using the "Endpoints" list in the Reference section below, add the appropriate @RequestMapping annotations to each of your methods. Endpoints should be at /people and /people/{id} as appropriate. You will have to use @PathVariable for id numbers in the URI and @RequestBody for Person objects sent in the requests.

Part 2:

Add the @Entity and @Id annotations to your Person class as shown in the Reference section. These tell Spring how to convert your Person objects to database entities when you pass them to a repository.

Create a PersonRepository interface that extends the CrudRepository interface. Be sure to specify the Person type parameter on CrudRepository<>. You will not need to implement this interface as Spring automatically generates an implementation at runtime.

Update your controller logic to use the PersonRepository instead of manually tracking Person objects in a list. You will need a PersonRepository field marked with the @Autowired annotation -- again, Spring will provide an implementation here automatically. You will need to use the findAll(), findOne(id), save(Person) and delete(id) methods of PersonRepository to fetch and save Person objects.

Part 3:

Now that your CRUD application is working, it's time to make sure the correct HTTP response codes are sent. Check the list of endpoints in the Reference section for the correct responses and change your PersonController methods to produce ResponseEntity objects containing the appropriate values.

Reference

Endpoints:

• POST /people - create a new person
  • Response: 201 Created
• GET /people - get the list of all people
  • Response: 200 OK
• GET /people/{id} - Get the person with id number {id}
  • Response: 200 OK if found, else 404 Not Found
• PUT /people/{id} - Update the person with id number {id}
  • Response: 200 OK if updated, 201 Created if a new entity was created
• DELETE /people/{id} - delete the person with id number {id}
  • Response: 204 No Content

Person class and ID configuration for H2:

@Entity
public class Person {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    ...
}

Resources

• For more practice building RESTful web services, see the Spring Boot Guides
• For an example of how to properly test an app such as this one, see this example repo