How to Submit a List of Entities to Spring Data Rest

How can I post a list of entities to Spring Data Rest in my application?

// Java code example for posting a list of entities to Spring Data REST
List<MyEntity> entities = Arrays.asList(new MyEntity(...), new MyEntity(...));
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<List<MyEntity>> requestEntity = new HttpEntity<>(entities, headers);
RestTemplate restTemplate = new RestTemplate();
restTemplate.postForEntity("http://localhost:8080/my-entities", requestEntity, Void.class);

Posting a list of entities to Spring Data REST allows clients to create multiple resources in a single request, which can significantly improve performance. Here's a step-by-step guide on how to effectively submit a list of entities to a Spring Data REST endpoint.

// Example code for posting a list of entities
List<MyEntity> entityList = Arrays.asList(new MyEntity(...), new MyEntity(...));
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<List<MyEntity>> request = new HttpEntity<>(entityList, headers);
ResponseEntity<Void> response = restTemplate.postForEntity("http://localhost:8080/my-entites", request, Void.class);

Causes

• The server may not handle lists appropriately without proper configuration.
• The provided list may not match the expected data structure for the endpoint.
• HTTP headers might not be set correctly, leading to content-type issues.

Solutions

• Ensure that the Spring Data REST endpoint is correctly set up to accept lists.
• Use the correct HTTP headers, particularly 'Content-Type: application/json'.
• Check that the entities' JSON format matches the expected structure defined in your Spring Data REST configuration.

Mistake: Forgetting to set the 'Content-Type' header when sending the request.

Solution: Always set the 'Content-Type' header to 'application/json' to inform the server about the data format.

Mistake: Sending an empty list or null instead of a properly structured list of entities.

Solution: Make sure the list contains valid entity objects before sending the request.

Mistake: Not handling the response correctly, assuming the post operation succeeded without checking the status code.

Solution: Always check the ResponseEntity to ensure the request was successful and handle any errors appropriately.