indexstore.java

关于 Jaoso新闻文章发布系统 --- --- --- --- --- --- --- --- --- --- --- --- --- -- 版本信息：Jaoso新闻文章发布系统 0.9.1b

package jaoso.framework.core.search.lucene;

import jaoso.framework.exception.SearchException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;

import java.io.File;
import java.io.IOException;


/**
 * @author        Quake Wang
 * @since        2004-5-23
 * @version $Revision: 1.1 $
 *
 **/
public class IndexStore {

    //~ Static fields/initializers =============================================

    /**  DOCUMENT ME! */
    private static final Log log = LogFactory.getLog(IndexStore.class);

    //~ Instance fields ========================================================

    /**  DOCUMENT ME! */
    private String indexDir;

    //~ Constructors ===========================================================

    /**
     * Creates a new IndexStore object.
     */
    public IndexStore() {

        init();
    }

    //~ Methods ================================================================

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public IndexReader createReader() throws IOException {

        createIndexDirectory(false);

        return IndexReader.open(getDirectory(false));
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public IndexSearcher createSearcher() throws IOException {

        createIndexDirectory(false);

        return new IndexSearcher(getDirectory(false));
    }

    /**
     * DOCUMENT ME!
     *
     * @param analyzer DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    public IndexWriter createWriter(Analyzer analyzer)
        throws IOException {

        createIndexDirectory(false);

        return new IndexWriter(getDirectory(false), analyzer, false);
    }

    /**
     * DOCUMENT ME!
     *
     * @param createIt DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     */
    private Directory getDirectory(boolean createIt) throws IOException {

        return FSDirectory.getDirectory(getIndexDir(), createIt);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    private boolean isIndexCreated() {

        boolean created = false;

        try {

            created = IndexReader.indexExists(getDirectory(false));
        } catch (IOException e) {

            log.error("Error creating reader: " + e, e);
        }

        return created;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    private String getIndexDir() {

        //return "index";
        return this.indexDir;
    }

    /**
     * DOCUMENT ME!
     *
     * @param forceCreate DOCUMENT ME!
     */
    private void createIndexDirectory(boolean forceCreate) {

        if (forceCreate || !isIndexCreated()) {

            try {

                new IndexWriter(getDirectory(true), null, true).close();
            } catch (IOException ioe) {

                log.error(ioe);
                throw new SearchException("Cannot create index directory");
            }
        }
    }

    /**
     * 初始化,如果索引目录没有建立则建立之
     */
    private void init() {

        if (indexDir == null) {

            String path = IndexStore.class.getResource("/")
                                          .getPath()
                                          .substring(1);
            path = path.substring(0, path.indexOf("classes")) + "index";
            this.indexDir = path;
        }

        File f = new File(this.indexDir);

        if (!f.exists()) {

            f.mkdirs();
        }
    }
}