Java tutorial
/* * Copyright 2010 The Fornax Project Team, including the original * author or authors. * * 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 org.sculptor.framework.accessimpl.mongodb; import com.mongodb.DB; import com.mongodb.DBAddress; import com.mongodb.DBCollection; import com.mongodb.Mongo; import com.mongodb.MongoOptions; import com.mongodb.ServerAddress; public class DbManager implements Cloneable { private static ThreadLocal<DbManager> threadInstance = new ThreadLocal<DbManager>(); private Mongo mongo; private DB db; private boolean initialized = false; private String dbname; private String dbUrl1; private String dbUrl2; private MongoOptions options = new MongoOptions(); public DbManager() { } public static DbManager getThreadInstance() { return threadInstance.get(); } public static void setThreadInstance(DbManager dbManager) { threadInstance.set(dbManager); } private boolean isAnotherThreadInstance() { DbManager other = getThreadInstance(); if (other == null) { return false; } return (other != this); } // lazy init @SuppressWarnings("deprecation") private synchronized void init() { if (initialized) { return; } if (dbname == null) { throw new IllegalStateException("MongoDB dbname not defined"); } try { if (dbUrl1 == null || dbUrl1.equals("")) { // default host/port, but with options mongo = new Mongo(new ServerAddress(), options); } else if (dbUrl2 != null && !dbUrl2.equals("")) { DBAddress left = new DBAddress(urlWithDbname(dbUrl1)); DBAddress right = new DBAddress(urlWithDbname(dbUrl2)); mongo = new Mongo(left, right, options); } else { DBAddress left = new DBAddress(urlWithDbname(dbUrl1)); mongo = new Mongo(left, options); } db = mongo.getDB(dbname); initialized = true; } catch (Exception e) { throw new RuntimeException(e.getMessage(), e); } } private String urlWithDbname(String dbUrl) { if (dbUrl == null) { return null; } if (!dbUrl.endsWith(dbname)) { return dbUrl + "/" + dbname; } return dbUrl; } public void requestStart() { getDB().requestStart(); } public void requestDone() { getDB().requestDone(); } public synchronized DB getDB() { if (isAnotherThreadInstance()) { return getThreadInstance().getDB(); } init(); return db; } public DBCollection getDBCollection(String name) { try { DBCollection coll = getDB().getCollection(name); return coll; } catch (Exception e) { throw new RuntimeException(e.getMessage(), e); } } public String getDbname() { return dbname; } public synchronized void setDbname(String dbname) { this.dbname = dbname; initialized = false; } public String getDbUrl1() { return dbUrl1; } public synchronized void setDbUrl1(String dbUrl1) { this.dbUrl1 = dbUrl1; initialized = false; } public String getDbUrl2() { return dbUrl2; } public synchronized void setDbUrl2(String dbUrl2) { this.dbUrl2 = dbUrl2; initialized = false; } public MongoOptions getOptions() { return options; } public synchronized void setOptions(MongoOptions options) { this.options = options; initialized = false; } @Override public Object clone() { try { return super.clone(); } catch (CloneNotSupportedException e) { // this shouldn't happen, since we are Cloneable throw new InternalError(); } } }