@JsonAppend not following sort order specified in @JsonPropertyOrder

[markwoon]

@JsonAppend javadoc claims to respect @JsonPropertyOrder but I'm not seeing that in version 2.9.2:

Simple test case:

  @Test
  public void testAppendOrder() throws Exception {

    AppendOrder data = new AppendOrder();
    ObjectMapper om = new ObjectMapper();
    String json = om.writer().withAttribute("@id", "1").writeValueAsString(data);
    System.out.println(json);
    assertTrue(json.indexOf("foo") > json.indexOf("@id"));
  }

  @JsonAppend(attrs = {
      @JsonAppend.Attr(value="@id", include= JsonInclude.Include.NON_EMPTY),
  })
  @JsonPropertyOrder(value = {"@id", "foo"})
  private static class AppendOrder {
    public String foo = "foo";
  }

[cowtowncoder]

I think javadoc may be off, as my recollection was that they can only be either prepended (before all regular properties) or appended (after all regular properties).

[PeterMue]

I'm facing the same problem. Javadoc of version 2.14.2 says:

although their placement may be further changed by the usual property-ordering functionality (alphabetic sorting; explicit ordering)

Is this still a javadoc issue, which means this is not possible or do i miss something?

[JooHyukKim]

@PeterMue I just tested it, check below test from my branch. It still has the same behavior.

https://github.com/JooHyukKim/jackson-databind/blob/66fcd99fa6cd2b21d600b35fd98227fad9d68b81/src/test/java/com/fasterxml/jackson/databind/ser/TestVirtualProperties.java#L156-L167

What we can do here is either

• revise the JavaDoc to make it clear what it does and does not
• or support @JsonPropertyOrder to include virtual properties added by @JsonAppend --I suppose it was not added for a reason, maybe @JsonAppend is applied at a later stage in serialization.

[cowtowncoder]

Ok, @JsonAppend inserted properties WILL NOT obey any sorting; if Javadocs claims otherwise it is wrong. @JooHyukKim is correct in that it is due to technical reasons.

There are no plans to change this behavior so +1 for fixing Javadocs not to make false claims.

EDIT: FWTW I am not against making virtual properties be sortable if that turns out doable. But at this moment they are not so documentation is wrong.