Store to JSON a PropertyBusinessObject containing a ListProperty - codenameone

Question

I have difficult to store to JSON a PropertyBusinessObject containing a ListProperty. I created the following test case, that works fine on the first execution, but fails on the second. Is my code wrong?
My test case if composed by four classes:
TestCaseJSON
public void init(Object context) {
[...]
DB.initPersistenceDB();
}
public void start() {
if(current != null){
current.show();
return;
}
Form hi = new Form("Hi World", BoxLayout.y());
hi.add(new Label("Hi World"));
hi.show();
DB.userDB.uniqueID.set("1");
DB.userDB.authToken.set("myToken");
InjuryDAO newInjury = new InjuryDAO();
DB.userDB.injuries.add(newInjury);
DB.saveDB();
}
DB
public class DB {
// User Database
public static UserDB userDB = new UserDB();
/**
* Call this method in the init(), it allows the database persistence and
* automatically restores the saved DB.
*/
public static void initPersistenceDB() {
Log.p("DB.initPersistenceDB executing", Log.DEBUG);
restoreDB();
}
/**
* Saves the UserDB to the Storage
*/
public static void saveDB() {
Log.p("DB.saveUserDB executing", Log.INFO);
userDB.getPropertyIndex().storeJSON("UserDB");
}
/**
* Restore the UserDB from the Storage, if it was previously saved to; this
* method is called by initPersistenceDB()
*/
private static void restoreDB() {
Log.p("DB.restoreUserDB executing", Log.INFO);
if (Storage.getInstance().exists("UserDB")) {
userDB.getPropertyIndex().loadJSON("UserDB");
}
}
}
UserDB
public class UserDB implements PropertyBusinessObject {
public final Property<String, UserDB> uniqueID = new Property<>("uniqueID", null);
public final Property<String, UserDB> authToken = new Property<>("authToken", null);
public final ListProperty<InjuryDAO, UserDB> injuries = new ListProperty<>("injuries");
public final PropertyIndex idx = new PropertyIndex(this, "UserDB",
uniqueID, authToken,
injuries
);
#Override
public PropertyIndex getPropertyIndex() {
return idx;
}
}
InjuryDAO
public class InjuryDAO implements PropertyBusinessObject {
// extra info
public final LongProperty<InjuryDAO> injuryCreationTime = new LongProperty<>("injuryCreationTime", System.currentTimeMillis());
// mandatory info
public final Property<Date, InjuryDAO> dateInjury = new Property<>("dateInjury", Date.class);
private final PropertyIndex idx = new PropertyIndex(this, "InjuryDAO",
injuryCreationTime, dateInjury
);
#Override
public PropertyIndex getPropertyIndex() {
return idx;
}
}
Before executing in the Simulator, I cleared the .cn1 directory (that is equivalent to Simulator, Clean Storage).
After the first execution, this is the log:
[EDT] 0:0:0,110 - DB.initPersistenceDB executing
[EDT] 0:0:0,110 - DB.restoreUserDB executing
[EDT] 0:0:0,178 - DB.saveUserDB executing
and this is the content of the UserDB file inside the .cn1 directory:
{
"injuries": [{"injuryCreationTime": 1558202520667}],
"authToken": "myToken",
"uniqueID": "1"
}
That's correct.
After the second execution, the log is identical to the previous one, but this is the wrong content of the UserDB file (note that the previous time stamp is lost):
{
"injuries": [
{"injuries": []},
{"injuryCreationTime": 1558202625655}
],
"authToken": "myToken",
"uniqueID": "1"
}
The expected correct result should be:
{
"injuries": [
{"injuryCreationTime": 1558202520667},
{"injuryCreationTime": 1558202625655}
],
"authToken": "myToken",
"uniqueID": "1"
}
Thank you for your support.

Answer 1

I think this:
public final ListProperty<InjuryDAO, UserDB> injuries = new ListProperty<>("injuries");
Should be changed to:
public final ListProperty<InjuryDAO, UserDB> injuries = new ListProperty<>("injuries", InjuryDAO.class);
If this doesn't work try:
public final ListProperty<InjuryDAO, UserDB> injuries = new ListProperty<>("injuries", InjuryDAO.class, null);