Java tutorial
/******************************************************************************* * Copyright (c) 2006-2012 * Software Technology Group, Dresden University of Technology * DevBoost GmbH, Berlin, Amtsgericht Charlottenburg, HRB 140026 * * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Software Technology Group - TU Dresden, Germany; * DevBoost GmbH - Berlin, Germany * - initial API and implementation ******************************************************************************/ package org.reuseware.sokan.index.solr; import static org.reuseware.sokan.index.solr.SolrConst.SYS_FIELD_ID; import java.util.ArrayList; import java.util.Collection; import java.util.List; import java.util.Set; import java.util.TreeSet; import java.util.Map.Entry; import java.util.logging.Level; import java.io.File; import org.apache.solr.client.solrj.SolrQuery; import org.apache.solr.client.solrj.SolrServer; import org.apache.solr.client.solrj.embedded.EmbeddedSolrServer; import org.apache.solr.client.solrj.response.QueryResponse; import org.apache.solr.common.util.NamedList; import org.apache.solr.core.CoreContainer; import org.apache.solr.core.CoreDescriptor; import org.apache.solr.core.SolrConfig; import org.apache.solr.core.SolrCore; import org.apache.solr.core.SolrResourceLoader; import org.apache.solr.schema.IndexSchema; import org.reuseware.sokan.ID; import org.reuseware.sokan.IndexRow; import org.reuseware.sokan.index.SokanIndexPlugin; import org.reuseware.sokan.index.util.CoreUtil; import org.reuseware.sokan.index.util.ResourceUtil; /** * Singleton that controls the Solr index. */ public final class SolrControler { /** * The singleton instance. */ public static final SolrControler INSTANCE = new SolrControler(); private static final String OR = " OR "; private static final int DEFAULT_ROWS = 100; private String solrHome; private String confDir; private String solrData; private SolrConfig solrConfig; private IndexSchema indexSchema; private SolrServer solrServer; private CoreContainer coreContainer; private SolrControler() { solrHome = SolrUtil.getSolrHome(); confDir = SolrUtil.getConfigurationDir(); solrData = SolrUtil.getDataDir(); SolrUtil.configureLogger(Level.SEVERE); setupSolrHome(); startSolrServer(); } /** * @return the Solr server */ public SolrServer getServer() { return solrServer; } /** * @return the indexSchema */ public IndexSchema getIndexSchema() { return indexSchema; } /** * Queries for all index rows. * * @return all index rows */ public List<IndexRow> query() { return query("*:*", -1); } /** * @return the names of all fields (columns) in the index */ public Set<String> getFieldNames() { NamedList<Object> list = adminQuery(); if (list == null) { return null; } Set<String> fields = new TreeSet<String>(); @SuppressWarnings("unchecked") NamedList<Object> fieldStatistic = (NamedList<Object>) list.get("fields"); for (Entry<String, ?> entry : fieldStatistic) { fields.add(entry.getKey()); } return fields; } /** * Queries for the index row of the artifact with the given ID. * * @param artifactID the artifact's ID * @return the artifact's index row */ public IndexRow query(ID artifactID) { String idString = ResourceUtil.idString(artifactID); idString = SolrUtil.prepareForQuery(idString); List<IndexRow> result = query(SYS_FIELD_ID + ":" + idString, 1); if (result == null || result.size() < 1) { return null; } return result.get(0); } /** * Queries for all index rows of the artifacts with the given IDs. * * @param artifactIDs the artifacts' IDs * @return the artifacts' index rows */ public List<IndexRow> query(Collection<ID> artifactIDs) { String idString; String queryString = ""; for (ID id : artifactIDs) { idString = ResourceUtil.idString(id); idString = SolrUtil.prepareForQuery(idString); queryString += SYS_FIELD_ID + ":" + idString + OR; } if (queryString.length() != 0) { queryString = CoreUtil.trimLastString(queryString, OR); } return query(queryString, artifactIDs.size()); } /** * Executes the query but limits the result to the given number of rows. * * @param queryString the query string * @param resultRows maximum number of result rows * @return the query result */ public List<IndexRow> query(String queryString, int resultRows) { if (queryString == null || queryString.equals("")) { return new ArrayList<IndexRow>(); } SolrQuery query = new SolrQuery(); query.setQuery(queryString); limit(query, resultRows); QueryResponse rsp = query(query); if (rsp == null) { return null; } else { return SolrUtil.toIndexRows(rsp.getResults()); } } /** * Executes the given Solr query. * * @param query the Solr query * @return the query result */ public QueryResponse query(SolrQuery query) { if (query == null) { return null; } QueryResponse rsp = null; query.add("debugQuery", "true"); try { rsp = solrServer.query(query); } catch (Exception e) { SokanIndexPlugin.logError("", e); } if (rsp == null) { return null; } return rsp; } /** * Stops the Solr server. */ public void stopServer() { if (coreContainer != null) { coreContainer.shutdown(); } } private boolean isCorrectSchema() { solrConfig = buildSolrConfig(); try { indexSchema = buildIndexSchema(solrConfig); } catch (RuntimeException e) { // schema.xml doesn't exist return false; } if (SolrUtil.wellFormed(indexSchema)) { return true; } solrConfig = null; indexSchema = null; return false; } /** * @return the size of the index. */ public int getSize() { NamedList<Object> list = adminQuery(); if (list == null) { return DEFAULT_ROWS; } @SuppressWarnings("unchecked") NamedList<Object> indexStatistic = (NamedList<Object>) list.get("index"); return (Integer) indexStatistic.get("numDocs"); // SolrQuery query = new SolrQuery().setQuery("*.*").setRows(0); // QueryResponse rsp = query(query); // long numFound = rsp.getResults().getNumFound(); // return new Integer((int) numFound); } /** * Limits the number of result rows in the given Solr query. * * @param query the Solr query * @param resultRows maximum number of result rows */ public void limit(SolrQuery query, int resultRows) { // Solr limits the number of result rows. // see solrconfig.xml '<requestHandler name="standard" (...)' if (resultRows < 0) { query.setRows(getSize()); } else { query.setRows(resultRows); } } private NamedList<Object> adminQuery() { SolrQuery query = new SolrQuery().setQuery("*.*").setQueryType("/admin/luke").setRows(0); QueryResponse rsp = query(query); return rsp.getResponse(); } private boolean setupSolrHome() { try { // create solreHome and configDir if needed File f = new File(confDir); if (!f.exists()) { f.mkdirs(); } } catch (Exception e) { SokanIndexPlugin.logError("", e); return false; } // copy configuration file if (!SolrUtil.copyIfNeeded(SolrConst.FILE_CONFIG, false)) { return false; } // schema file if (!SolrUtil.copyIfNeeded(SolrConst.FILE_SCHEMA, !isCorrectSchema())) { return false; } // // copy configuration file // if (!copyIfNeeded("protwords.txt")) // return false; // // // copy configuration file // if (!copyIfNeeded("stopwords.txt")) // return false; // // // copy configuration file // if (!copyIfNeeded("synonyms.txt")) // return false; return true; } private boolean startSolrServer() { if (solrConfig == null) { solrConfig = buildSolrConfig(); } if (indexSchema == null) { indexSchema = buildIndexSchema(solrConfig); if (indexSchema == null) { return false; } } coreContainer = new CoreContainer(new SolrResourceLoader(SolrResourceLoader.locateSolrHome())); CoreDescriptor dcore = new CoreDescriptor(coreContainer, "", solrConfig.getResourceLoader().getInstanceDir()); dcore.setConfigName(solrConfig.getResourceName()); dcore.setSchemaName(indexSchema.getResourceName()); SolrCore core = new SolrCore(SolrConst.CORE_NAME, solrData, solrConfig, indexSchema, dcore); coreContainer.register(core, false); solrServer = new EmbeddedSolrServer(coreContainer, SolrConst.CORE_NAME); return true; } private IndexSchema buildIndexSchema(SolrConfig solrConfig) { if (solrConfig == null) { return null; } IndexSchema indexSchema = new IndexSchema(solrConfig, SolrConst.FILE_SCHEMA, null); return indexSchema; } private SolrConfig buildSolrConfig() { SolrConfig solrConfig = null; try { solrConfig = new SolrConfig(solrHome, SolrConst.FILE_CONFIG, null); } catch (Exception e) { SokanIndexPlugin.logError("", e); } return solrConfig; } }