Step 3: Implement

[tfesenko]

Here we create a new class that will contain our implementations of the various API methods. This class will live alongside the existing PetsApiDelegate class in the demo project.

Use Java 8

We use Java 8 features in our implementation, but the project is configured to Use Java 7.

Update pom.xml of the generated project: <java.version>1.8</java.version>.
As pom.xml is now manually modified, to prevent overriding it with codegen, we need to add it to the.openapi-generator-ignore file.

Note: if you do not see .openapi-geneator-ignore in your project, you need to disable the .* resources filter here:

After making these changes, right-click on the generated project and select Maven -> Update project... to activate the change to Java 8.

New PetsApiDelegateImpl Class

For simplicity, I am using a simple HashMap instead of a database.

Create this class, named PetsApiDelegateImpl, alongside the PetsApiDelegate generated class:

package com.reprezen.demo.springboot.api;

@Service
public class PetsApiDelegateImpl implements PetsApiDelegate {
 	private final Map<Long, Pet> pets = Maps.newHashMap();
	private long nextId = 0l;
 	@Override
	public ResponseEntity<Pet> addPet(NewPet newPet) {
		Pet petToAdd = new Pet();
		petToAdd.id(nextId++).name(newPet.getName()).tag(newPet.getTag());
		pets.put(petToAdd.getId(), petToAdd);
		return new ResponseEntity<>(petToAdd, HttpStatus.CREATED);
	}
 	@Override
	public ResponseEntity<Void> deletePet(Long id) {
		if (!pets.containsKey(id)) {
			return new ResponseEntity<>(HttpStatus.NOT_FOUND);
		}
		pets.remove(id);
		return new ResponseEntity<>(HttpStatus.NO_CONTENT);
	}
 	@Override
	public ResponseEntity<Pet> findPetById(Long id) {
		if (!pets.containsKey(id)) {
			return new ResponseEntity<>(HttpStatus.NOT_FOUND);
		}
		return new ResponseEntity<>(pets.get(id), HttpStatus.ACCEPTED);
	}
 	@Override
	public ResponseEntity<List<Pet>> findPets(List<String> tags, Integer limitObject) {
		int limit = limitObject == null ? Integer.MAX_VALUE : limitObject;
		List<Pet> filteredPets = pets.values().stream()//
				.filter(pet -> (tags == null || tags.isEmpty()) ? true : tags.contains(pet.getTag()))//
				.limit(limit)//
				.collect(Collectors.toList());
		return new ResponseEntity<>(filteredPets, HttpStatus.ACCEPTED);
	}
 }

You can use the usual "Organize Imports" feature after creating this file to add the necessary imports, after which you should see a clean build. (Choose java.util.List and com.google.common.collect.Maps for those classes.)

The result of step 3 is on branch step_2b.

Now, you can run the API locally using mvn spring-boot:run. You can create a new pet and view it, you can also view all pets. To exercise the API, you can use a utility like curl or open the service in Swagger-UI at http://localhost:8080 and use its Try It Out feature.