Beispiel #1
0
    /**
     * 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;
    }
Beispiel #2
0
    /**
     * 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();
      }
    }