[FIXED] Spring Boot : Error :Cannot call sendError() after the response has been committed

Issue

I am getting this error . Cannot call sendError() after the response has been committed Can someone help me figure out why?.

    @Entity
    public class Product {

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private int id;

        @OneToOne(
                fetch = FetchType.LAZY,
                cascade = CascadeType.ALL
        )
        @JoinColumn(name = "details_id")
        private Details details;
//Getters and setters left out for brevity
    }


@Entity
public class Details {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String name;
    private String description;
    private float price;
    private float discount;
    @OneToOne(mappedBy = "details")
    private Product product;
}


@RestController
public class ProductController {
    @Autowired
    ProductRepository productRepository;

    @GetMapping("/getAllProducts")
    public Iterable<Product> getAllProducts(){
        return productRepository.findAll();
    }
}

   @RestController
public class DetialsController {
    @Autowired
    ProductRepository productRepository;

    @Autowired
    DetailsRepository detailsRepository;

    @PostMapping("/details")
    public Details addDetails(@RequestBody Details details) {
        Product newProduct = new Product();
        newProduct.setDetails(details);
        productRepository.save(newProduct);
        return detailsRepository.save(details);
    }
}

I am able to make the POST call to /details; for adding details successfully. But when i make GET call to /getAllProducts, I am getting this error Cannot call sendError() after the response has been committed

Solution

This is an issue with bidirectional relationships, as they hold references to each other, at deserialization, Jackson runs in an infinite loop. My first suggestion would be adding @JsonIgnore to one end of the relation.

@OneToOne(mappedBy = "details")
@JsonIgnore
private Product product;

Afterward, if that solved your issue, you can look over @JsonManagedReference/@JsonBackReference and @JsonIdentityInfo.

You can also look over this link for more insight

Answered By - Brad
Answer Checked By - Katrina (JavaFixing Volunteer)