Application: gvSIG desktop

import org.gvsig.fmap.data.feature.FeatureIndex;

import org.gvsig.tools.evaluator.Evaluator;

		this.provider = this.getFeatureSetOverIndex();

	private FeatureSetProvider getFeatureSetOverIndex() {

		class ApplyIndex {

			FeatureIndex index;

			Object[] data;

			String attrName;

			ApplyIndex(FeatureIndex index, String attrName, Object[] data) {

				this.index = index;

				this.attrName= attrName;

				this.data = data;

			}

		}

		if (!query.hasFilter()) {

			return null;

		}

		Evaluator evaluator;

		try {

			evaluator = query.getFilter();

		} catch( ClassCastException e) {

			return null;

		}

		try {

			List applyIndex = new ArrayList();

			Iterator indexes = this.store.getIndexes().iterator();

			while (indexes.hasNext()) {

				FeatureIndex index = (FeatureIndex) indexes

						.next();

				String[] attrs = index.getAttributeNames();

				for (int i=0; i<attrs.length; i++) {

					String attrname = attrs[i];

					Object[] data = evaluator.getFieldValues(attrname);

					if (data != null) {

						applyIndex.add(new ApplyIndex(index, attrname, data));

						break;

					}

				}

			}

			switch (applyIndex.size()) {

			case 0:

				return null;

			default:

				// FIXME: not implemented

				this.store

						.getLogger()

						.info(

								"Mas de un indice applica para la consulta. Se escoge arbitrariamente el primero.");

			case 1:

				ApplyIndex x = (ApplyIndex) applyIndex.get(0);

				return x.index.getFeatureSet(x.attrName, x.data);

			}

		} catch (Exception e) {

			this.store.getLogger().error("Error buscando indice que aplicar.",

					e);

			return null;

		}

	}