src/main/java/djmil/cashcard/CashCardController.java
package example.cashcard;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class CashCardController {
@GetMapping("/cashcards/{requestedId}")
public ResponseEntity<CashCard> findById(@PathVariable Long requestedId) {
if (requestedId.equals(99L)) {
CashCard cashCard = new CashCard(99L, 123.45);
return ResponseEntity.ok(cashCard);
} else {
return ResponseEntity.notFound().build();
}
}
}
@GetMapping
Needs the URI Path and tells Spring to route GET requests strictly to the findById method.
Alternative variant for providing URI mapping for @RestConttroller
@RestController
@RequestMapping("/cashcards")
public class CashCardController {
@GetMapping("/{requestedId}")
public ResponseEntity<String> findById() {
@PathVariable
Spring needs to know how to get the value of the requestedId parameter. This is done using the @PathVariable annotation. The fact that the parameter name matches the {requestedId} text (URI Path) within the @GetMapping parameter allows Spring to assign (inject) the correct value to the requestedId variable.
ResponseEntity
REST says that the Response needs to contain a Cash Card in its body, and a Response code of 200 (OK). Spring Web provides the ResponseEntity class for this purpose. It also provides several utility methods to produce Response Entities. Here ResponseEntity used to create a Response with code 200 (OK), and a body containing a CashCard.
Testing
Testing GET and other REST request is considerate to be IntegrationTests.
Also, after running the application, you can use browser (or any other web-testing tool) by visiting http://localhost:8080/cashcards/99