public static <C> List<C> fetch(Class<C> cls, DatabaseObject filteredBy) {
Database database = filteredBy.getDatabase();
@SuppressWarnings("unchecked")
AnnotatedRecordMapper<DatabaseObject> parentMapper =
(AnnotatedRecordMapper<DatabaseObject>) create(filteredBy.getClass());
AnnotatedRecordMapper<?> mapper = create(cls);
List<String> relationColumnNames = mapper.getRelationColumnNames(filteredBy.getClass());
List<String> idColumnNames = parentMapper.getIdColumnNames();
Map<String, Object> values = parentMapper.extractIds(filteredBy);
String relationExpression = "";
Object[] parameters = new Object[relationColumnNames.size()];
for (int i = 0; i < relationColumnNames.size(); i++) {
relationExpression += relationColumnNames.get(i) + "=?";
parameters[i] = values.get(idColumnNames.get(i));
if (parameters[i] == null) {
return new ArrayList<>();
}
}
try (Transaction transaction = database.beginReadOnlyTransaction()) {
transaction.associate(filteredBy);
return transaction.select(cls, relationExpression, parameters);
}
}
@SuppressWarnings("unchecked")
public static <T extends DatabaseObject> T fetch(T instance) {
Database database = instance.getDatabase();
Object[] ids;
synchronized (STUBS) {
ids = STUBS.get(instance);
}
if (database == null || ids == null) {
return instance;
}
AnnotatedRecordMapper<? extends Object> mapper = create(instance.getClass());
String whereClause = "";
for (String fieldName : mapper.getIdColumnNames()) {
if (!whereClause.isEmpty()) {
whereClause += " AND ";
}
whereClause += fieldName + "=?";
}
try (Transaction transaction = database.beginReadOnlyTransaction()) {
return (T) transaction.selectUnique(instance.getClass(), whereClause, ids);
}
}