Spring Hateoas #WIP#

https://github.com/spring-boot-tutorials/spring-hateoas

In this article we will configure Spring Boot with Hateoas.

Create Initial Code Base

Go to https://start.spring.io/
Add the following dependencies:
- spring-boot-starter-hateoas
- spring-boot-starter-web
- lombok
Click Generate

Dependencies

Dependencies used in pom.xml

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-hateoas</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

Model

Let’s create a new POJO src/main/java/com/example/spring_hateoas/model/Customer.java

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Customer extends RepresentationModel<Customer> {
    private String customerId;
    private String customerName;
    private String companyName;
}

Controller

Create a stub repository with fake data src/main/java/com/example/spring_hateoas/controller/DefaultController.java:

@RestController
@RequestMapping(value = "/customers")
public class DefaultController {

    private final List<Customer> customers = List.of(
            new Customer("id-1", "name-1","company-name-1"),
            new Customer("id-2", "name-2","company-name-2"),
            new Customer("id-3", "name-3","company-name-3")
    );

    public DefaultController() {
        for (Customer c : customers) {
            c.add(linkTo(DefaultController.class).slash(c.getCustomerId()).withSelfRel());
        }
    }

    /**
     * http://localhost:8080/customers/id-1
     * @param customerId
     * @return
     */
    @GetMapping(value = "/{customerId}", produces = { "application/hal+json" })
    public Customer getCustomerById(@PathVariable String customerId) {
        return customers.stream().filter(c -> c.getCustomerId().equals(customerId)).findAny().orElse(null);
    }
}

Run & Verify Application

Open terminal at project root and execute the following:

mvn spring-boot:run

Goto:

http://localhost:8080/customers/id-1

TODO

continue from: https://www.baeldung.com/spring-hateoas-tutorial#relations