Clarify DataBase JSon type to Object

[axel3rd]

Context: Some data are stored with json type in database (Table: grand_slam_day, field: players).

mpg-grandslam-populator/src/test/resources/datas-test.sql

Lines 67 to 68 in 0fa932e

INSERT INTO `grand_slam_day` (`id`, `grand_slam_id`, `day`, `label`, `players`) VALUES

(77, 9, 1, 'J0 : L2j0 L1j0 PLj0', '[{"pos": 9, "pts": 0, "diff": 0, "player": 73}, {"pos": 9, "pts": 0, "diff": 0, "player": 74}, {"pos": 9, "pts": 0, "diff": 0, "player": 75}, {"pos": 9, "pts": 0, "diff": 0, "player": 76}, {"pos": 9, "pts": 0, "diff": 0, "player": 77}, {"pos": 9, "pts": 0, "diff": 0, "player": 78}, {"pos": 9, "pts": 0, "diff": 0, "player": 79}, {"pos": 9, "pts": 0, "diff": 0, "player": 80}]'),

A conversion is needed to map that in a representative Object:

mpg-grandslam-populator/src/main/java/org/blonding/mpg/model/db/GrandSlamDay.java

Lines 23 to 24 in 0fa932e

	@Convert(converter = PlayerDayJsonConverter.class)
	private List<PlayerDayJson> players;

I don't understand why this "double" mapper usage is mandatory here, seems strange:

mpg-grandslam-populator/src/main/java/org/blonding/mpg/model/db/converter/PlayerDayJsonConverter.java

Lines 28 to 36 in 0fa932e

	public List<PlayerDayJson> convertToEntityAttribute(String json) {
	try {
	// TODO: Why this kind of mapper ??? To understand
	String s = json;
	if (s.startsWith("\"")) {
	s = mapper.readValue(s, String.class);
	}
	return mapper.readValue(s, new TypeReference<List<PlayerDayJson>>() {
	});

The unit test DataBaseUpdateGrandSlamDaysTaskletTest is useful for execute this part of code.

@litteautr : If you have any idea (perhaps you have already implemented this use case), many thanks 😘.