Jax-Rs + Jersey @Post of deeply nested objects throwing internal server error

Question

I'm trying to post a json using Postman and getting internal server error. I think the problem is while parsing json because while posting I'm passing an object which has variables which are nested as well.

Order Class:

public class Order {

        private long order_id;
        private long user_id;
        private List<OrderDetails> items;
        private Date order_date;
        private Double total;
        private String status;
        ......
}

OrderDetails Class:

public class OrderDetails {

    private Product product;
    private Integer quantity;
    ......
}

Product Class:

public class Product {

    private long prodId;
    private String prodName;
    private String prodDesc;
    private float price;
    .......
}

OrderResource class: it is not even calling this method I suppose because when I passed the data as string and changed the parameters to string, it is going inside the call and displaying it on console. But when I change it to Order again, it is throwing an MessageBodyWriter not found for media type=application/json, type=class java.util.HashMap, genericType=class java.util.HashMap.

@POST
    public Response insertorder(Order order, @Context UriInfo uriInfo) throws ApplicationException {
            if (!order.isValid()) {
            throw new ApplicationException("Order is invalid!");
        }

            System.out.println("Order details in Resource: "+order.getUser_id());

        Order response = new OrderDAO().InsertOrder(order);
        String newId = String.valueOf(response.getOrder_id());
        URI url = uriInfo.getAbsolutePathBuilder().path(newId).build();

        return Response.created(url)
                    .status(Status.CREATED)
                    .entity(response)
                    .build();
    }

OrderDAO class:

public Order InsertOrder(Order order) 
{
    Connection connection = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    connection = connect();
    double total=0;
    for(OrderDetails od: order.getItems()) {
        total += od.getProduct().getPrice() * od.getQuantity();
    }

    Order ret = null;

    try {
        pstmt = connection.prepareStatement("INSERT INTO main.orders_table(\n" + 
                "            user_id, order_date, total,status)\n" + 
                "    VALUES (?, ?, ?)",Statement.RETURN_GENERATED_KEYS);    
        pstmt.setLong(1, order.getUser_id());
        pstmt.setDate(2, (Date) order.getOrder_date());
        pstmt.setDouble(3,total);
        pstmt.setString(4,"pending");

        int affectedRows = pstmt.executeUpdate();

        if (affectedRows == 0) {
            throw new SQLException("Creating user failed, no rows affected.");
        }

        try (ResultSet generatedKeys = pstmt.getGeneratedKeys()) {
            if (generatedKeys.next()) {
                System.out.println("Inserted Order Id: "+generatedKeys.getLong(1));
                order.setOrder_id(generatedKeys.getLong(1)); //setting the Order ID to the inserted row Id
            }
            else {
                throw new SQLException("Creating user failed, no ID obtained.");
            }
        }

        ret = new Order(order.getOrder_id(),order.getUser_id(),order.getOrder_date(),order.getTotal(),order.getStatus());
    } 
    catch (Exception e) 
        {
            System.out.println("Error while inserting Order:" + e);
            e.printStackTrace();

        } finally {
            close(connection, pstmt, rs);
        }
    return ret;
}

Json String passing through Postman:

{
        "items": [
            {
                "product": {
                    "price": 2,
                    "prodDesc": "Pakistani Orange",
                    "prodId": 1002,
                    "prodName": "ORANGE"
                },
                "quantity": 5
            },
            {
                "product": {
                    "price": 3,
                    "prodDesc": "Kashmir Apple",
                    "prodId": 1001,
                    "prodName": "APPLE"
                },
                "quantity": 5
            }
        ],
        "order_date": "2008-07-06T00:00:00+08:00",
        "user_id": 2
    }

Can some one help me in solving this. TIA

Answer 1

Since you are using classes like Response, Order, you need to mention @consumes and @produces. Try using Put method, though Post will still work here.

Also configure postman properly, mention Content-Type, Accept as application/json each.

@POST
@Consumes(MediaType.APPLICATION_JSON)
@Produces(MediaType.APPLICATION_JSON)
public Response insertorder(Order order, @Context UriInfo uriInfo) throws ApplicationException {
        if (!order.isValid()) {
        throw new ApplicationException("Order is invalid!");
    }
..
}