/**
* No checking on the annotations - client could get unpredictable behaviour if annotations aren't
* configured properly.
*
* @return
*/
public void discover() {
jpaEntity = entityClass.isAnnotationPresent(javax.persistence.Entity.class);
Table table = (Table) entityClass.getAnnotation(Table.class);
if (!jpaEntity || table == null)
throw new UnsupportedOperationException(); // throw a more appropriate exception
tableName = table.name();
// Absolutely no validation annotation parsing!!
// this will ALWAYS parse annotations in this order: ID, EmbeddedId, and Column
Field[] fields = entityClass.getDeclaredFields();
for (Field f : fields) {
// first Id annotation
Annotation fan = f.getAnnotation(Id.class);
if (fan != null) {
Column col = (Column) f.getAnnotation(Column.class);
idMapping = new ColumnMapping(col.name(), f);
continue;
}
// Embedded ID
fan = f.getAnnotation(EmbeddedId.class);
if (fan != null) {
ArrayList<ColumnMapping> emList = new ArrayList<>();
for (Field inF : f.getType().getDeclaredFields()) {
if (inF.getAnnotation(Column.class) != null) {
Column innerId = (Column) inF.getAnnotation(Column.class);
// put column name in lower case as driver does
emList.add(new ColumnMapping(innerId.name().toLowerCase(), inF));
}
}
// column name
embedded = new Embedded(f, emList.toArray(emptyColArr));
continue;
}
// finally get the column
// there's special handling for map type - which is a definite area for improvement
fan = f.getAnnotation(Column.class);
if (fan != null) {
Column col = (Column) fan;
ColumnMapping mapping = new ColumnMapping(col.name(), f);
// special consideration for map
if (Map.class.isAssignableFrom(f.getType())) {
mapping.isMap = true;
}
// put in lower case as the driver
colsToFields.put(col.name().toLowerCase(), mapping);
continue;
}
}
}
/**
* Populates and iterates through a {@link Row} using {@link ColumnDefinitions} provided by the
* driver.
*
* @param row
* @return
*/
public T get(Row row) {
// Entity and its associated id object
T entity = null;
Object idObj = null;
try {
entity = entityClass.newInstance();
idObj = null;
ColumnMapping idcolmap = null;
// Note that this early invocation means that
// you can't populate on #setId in your java bean method
if (embedded != null) {
idObj = embedded.field.getType().newInstance();
embedded.set(entity, idObj);
} else {
idObj = idMapping.field.getType().newInstance();
idMapping.set(entity, idObj);
}
} catch (InstantiationException | IllegalAccessException e) {
throw new IllegalAccessError(
"A configuration exception has occurred in creating entity: " + entityClass);
}
ColumnDefinitions metaData = row.getColumnDefinitions();
List<Definition> defList = metaData.asList();
for (Definition def : defList) {
ColumnMapping mapping = colsToFields.get(def.getName());
if (mapping == null) {
// it could be an id column
if (idMapping != null && def.getName().equals(idMapping.name)) {
idMapping.set(entity, getValue(row, idMapping, def));
continue;
}
// else: need to find it, possible point of refactor
ColumnMapping nembed = null;
if (embedded != null) nembed = embedded.get(def.getName());
if (nembed != null) nembed.set(idObj, getValue(row, nembed, def));
continue;
}
Object value = getValue(row, mapping, def);
// set it
if (value != null) mapping.set(entity, value);
}
return entity;
}