IndexManager.java

/*
 * Copyright 2010 Impetus Infotech.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.impetus.kundera.index;

import java.util.List;

import javax.persistence.PersistenceException;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.util.Version;

import com.impetus.kundera.Constants;
import com.impetus.kundera.ejb.EntityManagerImpl;
import com.impetus.kundera.metadata.EntityMetadata;
import com.impetus.kundera.property.PropertyAccessorHelper;

/**
 * Manager responsible to co-ordinate with an Indexer. It is bound with
 * EntityManager.
 * 
 * @author animesh.kumar
 */
public class IndexManager {

    /** The indexer. */
    private Indexer indexer;

    /**
	 * The Constructor.
	 * 
	 * @param manager
	 *            the manager
	 */
    @SuppressWarnings("deprecation")
    public IndexManager(EntityManagerImpl manager) {
        indexer = new LucandraIndexer(manager.getClient(), 
        		new StandardAnalyzer(Version.LUCENE_CURRENT));
    }

    /**
     * Removes an object from Index.
     * 
     * @param metadata
     *            the metadata
     * @param entity
     *            the entity
     * @param key
     *            the key
     */
    public final void remove(EntityMetadata metadata, Object entity, String key) {
        try {
            indexer.unindex(metadata, key);
        } catch (Exception e) {
            throw new PersistenceException(e.getMessage());
        }
    }

    /**
     * Updates the index for an object.
     * 
     * @param metadata
     *            the metadata
     * @param entity
     *            the entity
     */
    public final void update(EntityMetadata metadata, Object entity) {
        try {
            String id = PropertyAccessorHelper.getId(entity, metadata);
            indexer.unindex(metadata, id);
            indexer.index(metadata, entity);
        } catch (Exception e) {
            throw new PersistenceException(e.getMessage());
        }
    }

    /**
     * Indexes an object.
     * 
     * @param metadata
     *            the metadata
     * @param entity
     *            the entity
     */
    public final void write(EntityMetadata metadata, Object entity) {
        indexer.index(metadata, entity);
    }

    /**
	 * Searches on the index. Note: Query must be in Indexer's understandable
	 * format
	 * 
	 * @param query
	 *            the query
	 * @return the list
	 */
    public final List<String> search(String query) {
        return search(query, Constants.INVALID, Constants.INVALID);
    }

    /**
	 * Search.
	 * 
	 * @param query
	 *            the query
	 * @param count
	 *            the count
	 * @return the list
	 */
    public final List<String> search(String query, int count) {
        return search(query, Constants.INVALID, count);
    }

    /**
	 * Search.
	 * 
	 * @param query
	 *            the query
	 * @param start
	 *            the start
	 * @param count
	 *            the count
	 * @return the list
	 */
    public final List<String> search(String query, int start, int count) {
        return indexer.search(query, start, count);
    }
}