@SuppressWarnings("unchecked")
@Override
public <T> ResultIterator<T> iterator(Select<T> query) {
final ResultIterator<DataRow> rows = performIteratedQuery(query);
QueryMetadata md = query.getMetaData(getEntityResolver());
if (md.isFetchingDataRows()) {
return (ResultIterator<T>) rows;
} else {
// this is a bit optimized version of 'objectFromDataRow' with
// resolver cached for reuse... still the rest is pretty suboptimal
ClassDescriptor descriptor = md.getClassDescriptor();
final ObjectResolver resolver = new ObjectResolver(this, descriptor, true);
return new ResultIterator<T>() {
@Override
public Iterator<T> iterator() {
return new ResultIteratorIterator<T>(this);
}
@Override
public List<T> allRows() {
List<T> list = new ArrayList<>();
while (hasNextRow()) {
list.add(nextRow());
}
return list;
}
@Override
public boolean hasNextRow() {
return rows.hasNextRow();
}
@Override
public T nextRow() {
DataRow row = rows.nextRow();
List<T> objects =
(List<T>) resolver.synchronizedObjectsFromDataRows(Collections.singletonList(row));
return (T) objects.get(0);
}
@Override
public void skipRow() {
rows.skipRow();
}
@Override
public void close() {
rows.close();
}
};
}
}
/**
* Creates a new IncrementalFaultList using a given DataContext and query.
*
* @param dataContext DataContext used by IncrementalFaultList to fill itself with objects.
* @param query Main query used to retrieve data. Must have "pageSize" property set to a value
* greater than zero.
* @param maxFetchSize maximum number of fetches in one query
*/
public IncrementalFaultList(DataContext dataContext, Query query, int maxFetchSize) {
QueryMetadata metadata = query.getMetaData(dataContext.getEntityResolver());
if (metadata.getPageSize() <= 0) {
throw new CayenneRuntimeException(
"Not a paginated query; page size: " + metadata.getPageSize());
}
this.dataContext = dataContext;
this.pageSize = metadata.getPageSize();
this.rootEntity = metadata.getObjEntity();
if (rootEntity == null) {
throw new CayenneRuntimeException(
"Pagination is not supported for queries not rooted in an ObjEntity");
}
// create an internal query, it is a partial replica of
// the original query and will serve as a value holder for
// various parameters
this.internalQuery = new SelectQuery<Object>(rootEntity);
this.internalQuery.setFetchingDataRows(metadata.isFetchingDataRows());
this.internalQuery.setPrefetchTree(metadata.getPrefetchTree());
this.helper = createHelper(metadata);
this.idWidth = metadata.getDbEntity().getPrimaryKeys().size();
List<Object> elementsUnsynced = new ArrayList<>();
fillIn(query, elementsUnsynced);
this.elements = Collections.synchronizedList(elementsUnsynced);
this.maxFetchSize = maxFetchSize;
}
/** @since 3.0 */
IncrementalListHelper createHelper(QueryMetadata metadata) {
if (metadata.isFetchingDataRows()) {
return new DataRowListHelper();
} else {
return new PersistentListHelper();
}
}