Java tutorial
/* * Copyright Robert Newson * * 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.github.rnewson.couchdb.lucene; import com.github.rnewson.couchdb.lucene.couchdb.Couch; import com.github.rnewson.couchdb.lucene.couchdb.Database; import com.github.rnewson.couchdb.lucene.couchdb.DesignDocument; import com.github.rnewson.couchdb.lucene.couchdb.View; import com.github.rnewson.couchdb.lucene.util.ServletUtils; import org.apache.commons.configuration.Configuration; import org.apache.commons.configuration.ConfigurationException; import org.apache.commons.configuration.HierarchicalINIConfiguration; import org.apache.commons.io.FileUtils; import org.apache.commons.lang.StringUtils; import org.apache.http.client.HttpClient; import org.apache.log4j.Logger; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.util.*; public final class LuceneServlet extends HttpServlet { private static final Logger LOG = Logger.getLogger(LuceneServlet.class); private static final long serialVersionUID = 1L; private final HttpClient client; private final Map<Database, DatabaseIndexer> indexers = new HashMap<Database, DatabaseIndexer>(); private final HierarchicalINIConfiguration ini; private final File root; private final Map<Database, Thread> threads = new HashMap<Database, Thread>(); public LuceneServlet() throws ConfigurationException, IOException { final Config config = new Config(); this.client = config.getClient(); this.root = config.getDir(); this.ini = config.getConfiguration(); } public LuceneServlet(final HttpClient client, final File root, final HierarchicalINIConfiguration ini) { this.client = client; this.root = root; this.ini = ini; } private void cleanup(final HttpServletRequest req, final HttpServletResponse resp) throws IOException, JSONException { final Couch couch = getCouch(req); final Set<String> dbKeep = new HashSet<String>(); final JSONArray databases = couch.getAllDatabases(); for (int i = 0; i < databases.length(); i++) { final Database db = couch.getDatabase(databases.getString(i)); final UUID uuid = db.getUuid(); if (uuid == null) { continue; } dbKeep.add(uuid.toString()); final Set<String> viewKeep = new HashSet<String>(); for (final DesignDocument ddoc : db.getAllDesignDocuments()) { for (final View view : ddoc.getAllViews().values()) { viewKeep.add(view.getDigest()); } } // Delete all indexes except the keepers. final File[] dirs = DatabaseIndexer.uuidDir(root, db.getUuid()).listFiles(); if (dirs != null) { for (final File dir : dirs) { if (!viewKeep.contains(dir.getName())) { LOG.info("Cleaning old index at " + dir); FileUtils.deleteDirectory(dir); } } } } // Delete all directories except the keepers. for (final File dir : root.listFiles()) { if (!dbKeep.contains(dir.getName())) { LOG.info("Cleaning old index at " + dir); FileUtils.deleteDirectory(dir); } } resp.setStatus(202); ServletUtils.sendJsonSuccess(req, resp); } private Couch getCouch(final HttpServletRequest req) throws IOException { final String sectionName = new PathParts(req).getKey(); final Configuration section = ini.getSection(sectionName); if (!section.containsKey("url")) { throw new FileNotFoundException(sectionName + " is missing or has no url parameter."); } return new Couch(client, section.getString("url")); } private synchronized DatabaseIndexer getIndexer(final Database database) throws IOException, JSONException { DatabaseIndexer result = indexers.get(database); Thread thread = threads.get(database); if (result == null || thread == null || !thread.isAlive()) { result = new DatabaseIndexer(client, root, database, ini); thread = new Thread(result); thread.start(); result.awaitInitialization(); if (result.isClosed()) { return null; } else { indexers.put(database, result); threads.put(database, thread); } } return result; } private DatabaseIndexer getIndexer(final HttpServletRequest req) throws IOException, JSONException { final Couch couch = getCouch(req); final Database database = couch.getDatabase(new PathParts(req).getDatabaseName()); return getIndexer(database); } private void handleWelcomeReq(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException, JSONException { final Package p = this.getClass().getPackage(); final JSONObject welcome = new JSONObject(); welcome.put("couchdb-lucene", "Welcome"); welcome.put("version", p.getImplementationVersion()); ServletUtils.sendJson(req, resp, welcome); } @Override protected void doGet(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException { try { doGetInternal(req, resp); } catch (final JSONException e) { resp.sendError(500); } } private void doGetInternal(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException, JSONException { switch (StringUtils.countMatches(req.getRequestURI(), "/")) { case 1: handleWelcomeReq(req, resp); return; case 5: final DatabaseIndexer indexer = getIndexer(req); if (indexer == null) { ServletUtils.sendJsonError(req, resp, 500, "error_creating_index"); return; } if (req.getParameter("q") == null) { indexer.info(req, resp); } else { indexer.search(req, resp); } return; } ServletUtils.sendJsonError(req, resp, 400, "bad_request"); } @Override protected void doPost(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException { try { doPostInternal(req, resp); } catch (final JSONException e) { resp.sendError(500); } } private void doPostInternal(final HttpServletRequest req, final HttpServletResponse resp) throws IOException, JSONException { switch (StringUtils.countMatches(req.getRequestURI(), "/")) { case 3: if (req.getPathInfo().endsWith("/_cleanup")) { cleanup(req, resp); return; } break; case 5: { final DatabaseIndexer indexer = getIndexer(req); if (indexer == null) { ServletUtils.sendJsonError(req, resp, 500, "error_creating_index"); return; } indexer.search(req, resp); break; } case 6: final DatabaseIndexer indexer = getIndexer(req); indexer.admin(req, resp); return; } ServletUtils.sendJsonError(req, resp, 400, "bad_request"); } }