Cannot deserialize value of type X from String

The fix

Tell Jackson the format. For a date, put @JsonFormat(pattern = "dd/MM/yyyy") on the field, as in the fixed code. Or have the sender use a format Jackson already reads, like 2026-10-14. For a number field, the sender has to send a number.

{
  "id": 7,
  "orderDate": "14/10/2026"
}

public class Order {
  public long id;
  public Date orderDate;
}

Order order = mapper.readValue(json, Order.class);

public class Order {
  public long id;

  @JsonFormat(pattern = "dd/MM/yyyy")
  public Date orderDate;
}

Order order = mapper.readValue(json, Order.class);

How the message appears

Jackson 2, then Jackson 3, then Spring (the same on 6.2 and 7.0). The last two are other cases: text in an int field, and an empty string in an int field, which only Jackson 3 rejects.

What causes it

1. 1

   A date format Jackson does not read

   The example sends "14/10/2026" to a java.util.Date. The message lists the formats Jackson tried: "yyyy-MM-dd'T'HH:mm:ss.SSSX", "yyyy-MM-dd'T'HH:mm:ss.SSS", "EEE, dd MMM yyyy HH:mm:ss zzz" and "yyyy-MM-dd". A day-first date is none of them.

2. 2

   Text in a number field

   "abc" for an int gives the same kind of message: from String "abc": not a valid, then the type. The end of the message names the field, quantity.

3. 3

   An empty string in a number field

   "" for an int depends on the version. Jackson 2 reads it with no error. Jackson 3 throws Cannot coerce and tells you to disable DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES if you want to allow it. So moving from Jackson 2 to 3 can turn a request that used to work into an error.

4. 4

   Spring shows the value but not where

   Spring prints JSON parse error: and the message above, without the at [Source: ...] line. The value is still there, so you can see what the client really sent. Other Spring messages are on the Spring page.

Worth knowing