private final void populateFieldFromFullyQualifiedColumn(
T entity, Field field, KijiColumn column, KijiRowData row)
throws IOException, IllegalAccessException {
if (column.maxVersions() == 1) {
// Field represents a single value from a fully-qualified column:
LOG.debug(
"Populating field '{}' from column '{}:{}'.",
field,
column.family(),
column.qualifier());
KijiCell<?> cell = row.getMostRecentCell(column.family(), column.qualifier());
if (cell == null) return;
Object value = cell.getData();
if (field.getType() == KijiCell.class) {
value = cell;
} else if (field.getType() == String.class && value != null) {
value = value.toString();
}
// If there is no cell for a field with a primitive type, use the default value:
if ((null == value) && field.getType().isPrimitive()) {
value = Defaults.defaultValue(field.getType());
}
field.set(entity, value);
} else {
// Field represents a time-series from a fully-qualified column:
if (column.pageSize() > 0) {
final ColumnVersionIterator<?> iterator =
new ColumnVersionIterator<Object>(
row, column.family(), column.qualifier(), column.pageSize());
field.set(entity, iterator);
} else {
Object value = null;
if (field.getType() == KijiCellValueIterator.class) {
value =
new KijiCellValueIterator<Object>(
row.iterator(column.family(), column.qualifier()));
} else if (field.getType() == TimeSeries.class) {
final TimeSeries<Object> timeseries = new TimeSeries<Object>();
for (final KijiCell<Object> cell :
row.asIterable(column.family(), column.qualifier())) {
timeseries.put(cell.getTimestamp(), cell.getData());
}
value = timeseries;
}
field.set(entity, value);
}
}
}
/**
* Populates an entity from a row.
*
* @param entity Entity object to populate from a row.
* @param row Kiji row to populate the entity from.
* @return the populated entity.
* @throws IllegalAccessException
* @throws IOException
*/
public T populateEntityFromRow(T entity, KijiRowData row)
throws IllegalAccessException, IOException {
// Populate fields from the row columns:
for (final Field field : mColumnFields) {
final KijiColumn column = field.getAnnotation(KijiColumn.class);
Preconditions.checkState(column != null);
if (column.qualifier().isEmpty()) {
// Field is populated from a map-type family:
populateFieldFromMapTypeFamily(entity, field, column, row);
} else {
// Field is populated from a fully-qualified column:
populateFieldFromFullyQualifiedColumn(entity, field, column, row);
}
}
// Populate fields from the row entity ID:
for (final Field field : mEntityIdFields) {
final EntityIdField eidField = field.getAnnotation(EntityIdField.class);
Preconditions.checkState(eidField != null);
final int index = mRowKeyComponentIndexMap.get(eidField.component());
field.set(entity, row.getEntityId().getComponentByIndex(index));
}
return entity;
}
/**
* Populates a KijiDataRequest from this entity specification.
*
* @param builder Builder for the KijiDataRequest to populate.
*/
public void populateColumnRequests(KijiDataRequestBuilder builder) {
for (final Field field : mColumnFields) {
final KijiColumn column = field.getAnnotation(KijiColumn.class);
Preconditions.checkState(column != null);
final ColumnsDef def =
ColumnsDef.create()
.withMaxVersions(column.maxVersions())
.withPageSize(column.pageSize());
if (column.qualifier().isEmpty()) {
def.addFamily(column.family());
} else {
def.add(column.family(), column.qualifier());
}
builder.addColumns(def);
}
}
/**
* Initializes a new specification for an Entity from an annotated Java class.
*
* @param klass Annotated Java class to derive an entity specification from.
* @param kiji Kiji instance where to fetch entities from.
* @throws IOException on I/O error.
*/
public EntitySpec(Class<T> klass, Kiji kiji) throws IOException {
mClass = klass;
final KijiEntity entity = klass.getAnnotation(KijiEntity.class);
Preconditions.checkArgument(
entity != null, "Class '{}' has no @KijiEntity annotation.", klass);
mTableName = entity.table();
final KijiTable table = kiji.openTable(mTableName);
try {
final KijiTableLayout layout = table.getLayout();
// TODO: Support deprecated RowKeyFormat?
final RowKeyFormat2 rowKeyFormat = (RowKeyFormat2) layout.getDesc().getKeysFormat();
final Map<String, RowKeyComponent> rkcMap = Maps.newHashMap();
final Map<String, Integer> rkcIndexMap = Maps.newHashMap();
for (int index = 0; index < rowKeyFormat.getComponents().size(); ++index) {
final RowKeyComponent rkc = rowKeyFormat.getComponents().get(index);
rkcMap.put(rkc.getName(), rkc);
rkcIndexMap.put(rkc.getName(), index);
}
mRowKeyComponentMap = ImmutableMap.copyOf(rkcMap);
mRowKeyComponentIndexMap = ImmutableMap.copyOf(rkcIndexMap);
// --------------------------------------------------------------------
// Parse fields with annotations from the entity class:
final List<Field> columnFields = Lists.newArrayList();
final List<Field> entityIdFields = Lists.newArrayList();
for (final Field field : mClass.getDeclaredFields()) {
final KijiColumn column = field.getAnnotation(KijiColumn.class);
final EntityIdField eidField = field.getAnnotation(EntityIdField.class);
if ((column != null) && (eidField != null)) {
throw new IllegalArgumentException(
String.format(
"Field '%s' cannot have both @KijiColumn and @EntityIdField annotations.",
field));
} else if (column != null) {
LOG.debug("Validating column field '{}'.", field);
field.setAccessible(true);
columnFields.add(field);
final FamilyLayout flayout = layout.getFamilyMap().get(column.family());
Preconditions.checkArgument(
flayout != null,
"Field '%s' maps to non-existing family '%s' from table '%s'.",
field,
column.family(),
mTableName);
if (column.qualifier().isEmpty()) {
// Request for a map-type family:
Preconditions.checkArgument(
flayout.isMapType(),
"Field '%s' maps to family '%s' from table '%s' which is not a map-type family.",
field,
column.family(),
mTableName);
// Validate field type:
if (column.pageSize() > 0) {
Preconditions.checkArgument(
MapFamilyVersionIterator.class.isAssignableFrom(field.getType()),
"Fields mapped to map-type family with paging enabled must be "
+ "MapFamilyVersionIterator, got '{}'.",
field.getType());
} else {
// TODO Validate type when no paging enabled on map-type family.
}
} else {
// Request for a fully-qualified column:
final ColumnLayout clayout = flayout.getColumnMap().get(column.qualifier());
Preconditions.checkArgument(
flayout != null,
"Field '%s' maps to non-existing column '%s:%s' from table '%s'.",
field,
column.family(),
column.qualifier(),
mTableName);
// Validate field type:
if (column.pageSize() > 0) {
Preconditions.checkArgument(
ColumnVersionIterator.class.isAssignableFrom(field.getType()),
"Fields mapped to column with paging enabled must be "
+ "ColumnVersionIterator, got '{}'.",
field.getType());
} else {
// TODO Validate type when no paging enabled on the column.
}
}
} else if (eidField != null) {
LOG.debug("Validating entity ID field '{}'.", field);
field.setAccessible(true);
entityIdFields.add(field);
final RowKeyComponent rkc = mRowKeyComponentMap.get(eidField.component());
Preconditions.checkArgument(
rkc != null,
"Field '%s' maps to unknown entity ID component '%s'.",
field,
eidField.component());
} else {
LOG.debug("Ignoring field '{}' with no annotation.", field);
}
}
mColumnFields = ImmutableList.copyOf(columnFields);
mEntityIdFields = ImmutableList.copyOf(entityIdFields);
} finally {
table.release();
}
}