Java tutorial
/** * Licensed to JumpMind Inc under one or more contributor * license agreements. See the NOTICE file distributed * with this work for additional information regarding * copyright ownership. JumpMind Inc licenses this file * to you under the GNU General Public License, version 3.0 (GPLv3) * (the "License"); you may not use this file except in compliance * with the License. * * You should have received a copy of the GNU General Public License, * version 3.0 (GPLv3) along with this library; if not, see * <http://www.gnu.org/licenses/>. * * 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.jumpmind.symmetric.io; import java.net.UnknownHostException; import java.util.HashMap; import java.util.Map; import org.jumpmind.symmetric.SymmetricException; import org.jumpmind.symmetric.service.IParameterService; import com.mongodb.DB; import com.mongodb.MongoClient; import com.mongodb.WriteConcern; public class SimpleMongoClientManager implements IMongoClientManager { protected IParameterService parameterService; protected String name = "mongodb"; /* * This is static because the MongoClient is thread safe and wraps a pool of * connections */ protected static Map<String, MongoClient> clients = new HashMap<String, MongoClient>(); protected DB currentDB; public SimpleMongoClientManager(IParameterService parameterService, String name) { this.name = name; this.parameterService = parameterService; } @Override public MongoClient get() { MongoClient client = clients.get(name); if (client == null) { synchronized (clients) { if (client == null) { int port = 27017; String host = "localhost"; if (parameterService != null) { port = parameterService.getInt(name + MongoConstants.PORT, port); host = parameterService.getString(name + MongoConstants.HOST, host); } try { client = new MongoClient(host, port); clients.put(name, client); } catch (UnknownHostException e) { throw new SymmetricException(e); } } } } return client; } @Override public DB getDB(String name) { if (currentDB == null || !currentDB.getName().equals(name)) { currentDB = get().getDB(name); /** * TODO make this a property */ currentDB.setWriteConcern(WriteConcern.ACKNOWLEDGED); String username = null; char[] password = null; if (parameterService != null) { username = parameterService.getString(name + MongoConstants.USERNAME, username); String passwordString = parameterService.getString(name + MongoConstants.PASSWORD, null); if (passwordString != null) { password = passwordString.toCharArray(); } } if (username != null && !currentDB.authenticate(username, password)) { throw new SymmetricException("Failed to authenticate with the mongo database: " + name); } } return currentDB; } @Override public String getName() { return name; } }