How to save many objects in the same request using Spring Boot Data Rest

Question

I'm try save a array of an Entity using POST method passing an array for rest resource, but I have an error:

org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not deserialize instance of br.com.servtech.almox.model.Item out of START_ARRAY token
 at [Source: org.apache.catalina.connector.CoyoteInputStream@2af1e451; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of br.com.servtech.almox.model.Item out of START_ARRAY token
 at [Source: org.apache.catalina.connector.CoyoteInputStream@2af1e451; line: 1, column: 1]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:228) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readInternal(AbstractJackson2HttpMessageConverter.java:205) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]

When's I send one object the data, the data is saved very well!

---

My Entity:

@Entity
public class Item implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Basic
    private String name;

    @Basic
    private Integer quantity;

    @Basic
    private Double cash;

    @ManyToOne
    private Requirement requirement;

    //getters and setters
}

My Repository:

@RepositoryRestResource
@CrossOrigin
public interface ItemDAO extends CrudRepository<Item, Long> {

}

The Data:

[{ 
    "name": "A1", 
    "quantity": 3, 
    "cash": 5.80
}, { 
    "name": "B2", 
    "quantity": 3, 
    "cash": 5.80
}]

I've tried to using the Content-Type application/json and using with text/uri-list. What is wrong? I do some more setup?

Answer 1

What is wrong is that is trying to read your request body as an Item, when it is in fact multiple Items.

I believe you have two choices here. What I would normally do in this situation would be to create another resource, such as ItemCollection, to wrap multiple Items. Then you could have standard REST functionality to take in an ItemCollection, which would essentially handle multiple Items.

Your second option would be to manually override a method to handle multiple itmes: http://docs.spring.io/spring-data/rest/docs/current/reference/html/#customizing-sdr.overriding-sdr-response-handlers