[FIXED] 500 Internal Server Error in spring boot post API

Issue

I'm trying to create a post API in a spring boot app but it's not working and i can't find the issue in the code

This is service:

  @Transactional
    public Invoice saveInvoice(Invoice invoice) {
        Invoice newInvoice = invoiceRepository.save(invoice);
        return newInvoice;
    }

This is the controller:

@PostMapping("/save")
public ResponseEntity<Invoice> addInvoice(@RequestBody InvoiceDTO invoice) {
    try {
        Invoice newInvoice = invoiceService
                .saveInvoice(new Invoice(invoice.getSerialNumber(), invoice.getStatus(), invoice.getCreatedDate()));
        return new ResponseEntity<>(newInvoice, HttpStatus.CREATED);
    } catch (Exception e) {
        return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
    }
}

and this is the model :

@Entity
@Table(name = "invoice")
public class Invoice {

    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    private int id;
    @Column(name = "serial_number")
    private long serialNumber;
    @Column(name = "status")
    private String status;
    @Column(name = "created_date")
    private Timestamp createdDate;
    @Column(name = "is_deleted")
    private boolean isDeleted;

    @ManyToOne
    @JoinColumn(name = "customer_id")
    private Customer customer;

    @ManyToOne
    @JoinColumn(name = "employee_id")
    private Employee employee;

    @OneToMany
    private Set<InvoiceHistory> invoiceHistories;

    @ManyToMany
    private Set<Item> items;

    public Invoice(long serialNumber, String status, Timestamp createdDate) {
        this.serialNumber = serialNumber;
        this.status = status;
        this.createdDate = createdDate;
        this.isDeleted = false;
    }
}

But when I am running in in postman its returning 500 Internal Server Error

Update error message :

, message=Cannot invoke "com.example.invoices.repository.IInvoiceRepository.save(Object)" because "this.invoiceRepository" is null, path=/invoice/save}]

where's the problem ?

Solution

For your service class, how are you declaring and creating invoiceRepository? If it's like this:

private InvoiceRepository invoiceRepository;

Then you need to add an @Autowired:

@Autowired
private InvoiceRepository invoiceRepository;

If you do have it @Autowired, make sure your service class is annotated with @Service:

@Service
public class InvoiceService {...}

If you have that, make sure you aren't creating InvoiceService with "new" in your controller. Instead of:

private InvoiceService invoiceService = new InvoiceService();

or "new"ing it in a constructor, use @Autowire

@Autowire
private InvoiceService invoiceService;

Answered By - bmargoat
Answer Checked By - Clifford M. (JavaFixing Volunteer)