Serializing List with null values leads to corrupt CSV

[sothmann]

If I serialize a List of objects, e.g. a list of POJOs and the list contains null values, the next line after the null value is corrupt.

Example:

List<MyPojo> list = Arrays.asList(
      new MyPojo("foo", "bar", 123),
      null,
      new MyPojo("test", "abc", 42)
);

gets serialized to

foo,bar,123
,abc,42

instead of the expected output of

foo,bar,123
test,abc,42

Tested with 2.5.4 and 2.6.0-rc4.

Here is a complete test case:

public class JacksonCsvNullInListTest {
  @Test
  public void testNullInList() throws JsonProcessingException {
    CsvMapper mapper = new CsvMapper();
    CsvSchema schema = mapper.schemaFor(MyPojo.class);
    final ObjectWriter writer = mapper.writer(schema);

    List<MyPojo> list = Arrays.asList(
      new MyPojo("foo", "bar", 123),
      null,
      new MyPojo("test", "abc", 42)
    );

    String expectedCsv = "foo,bar,123\ntest,abc,42\n";
    String actualCsv = writer.writeValueAsString(list);
    assertEquals(expectedCsv, actualCsv);
  }

  private static class MyPojo {
    private String prop1;
    private String prop2;
    private Integer prop3;

    public MyPojo(String prop1, String prop2, Integer prop3) {
      this.prop1 = prop1;
      this.prop2 = prop2;
      this.prop3 = prop3;
    }

    public String getProp1() {
      return prop1;
    }

    public String getProp2() {
      return prop2;
    }

    public Integer getProp3() {
      return prop3;
    }
  }
}

[cowtowncoder]

Thank you for reporting this. A nasty bug indeed, will hope to fix it ASAP.

[cowtowncoder]

Hmmh. Assuming this is related to #69 somehow. Investigating.

[cowtowncoder]

Seems like fix for #69 should be generalized slightly, to apply not only to root-level values but also to "wrap as array", or serializing arrays/Lists.

[sothmann]

Thanks for fixing this issue!

[cowtowncoder]

Np, thank you for reporting this. And right in time to be included in 2.6.0, to be released in a day or two.

[sothmann]

Perfect, good to hear that 👍
Waiting for the 2.6.0 Release (or another RC that contains the fix)