JAVA单例MongoDB工具类
JAVA驱动版本：
<!-- MongoDB驱动 --> <dependency> <groupId>org.mongodb</groupId> <artifactId>mongo-java-driver</artifactId> <version>3.0.2</version> </dependency>
工具类代码如下：
package utils; import java.util.ArrayList; import java.util.List; import org.apache.commons.configuration.CompositeConfiguration; import org.apache.commons.configuration.ConfigurationException; import org.apache.commons.configuration.PropertiesConfiguration; import org.bson.Document; import org.bson.conversions.Bson; import org.bson.types.ObjectId; import com.mongodb.BasicDBObject; import com.mongodb.MongoClient; import com.mongodb.MongoClientOptions; import com.mongodb.MongoClientOptions.Builder; import com.mongodb.WriteConcern; import com.mongodb.client.MongoCollection; import com.mongodb.client.MongoCursor; import com.mongodb.client.MongoDatabase; import com.mongodb.client.MongoIterable; import com.mongodb.client.model.Filters; import com.mongodb.client.result.DeleteResult; /** * MongoDB工具类 Mongo实例代表了一个数据库连接池，即使在多线程的环境中，一个Mongo实例对我们来说已经足够了<br> * 注意Mongo已经实现了连接池，并且是线程安全的。 <br> * 设计为单例模式， 因 MongoDB的Java驱动是线程安全的，对于一般的应用，只要一个Mongo实例即可，<br> * Mongo有个内置的连接池（默认为10个） 对于有大量写和读的环境中，为了确保在一个Session中使用同一个DB时，<br> * DB和DBCollection是绝对线程安全的<br> * * @author zhoulingfei * @date 2015-5-29 上午11:49:49 * @version 0.0.0 * @Copyright (c)1997-2015 NavInfo Co.Ltd. All Rights Reserved. */ public enum MongoDBUtil { /** * 定义一个枚举的元素，它代表此类的一个实例 */ instance; private MongoClient mongoClient; static { System.out.println("===============MongoDBUtil初始化========================"); CompositeConfiguration config = new CompositeConfiguration(); try { config.addConfiguration(new PropertiesConfiguration("mongodb.properties")); } catch (ConfigurationException e) { e.printStackTrace(); } // 从配置文件中获取属性值 String ip = config.getString("host"); int port = config.getInt("port"); instance.mongoClient = new MongoClient(ip, port); // or, to connect to a replica set, with auto-discovery of the primary, supply a seed list of members // List<ServerAddress> listHost = Arrays.asList(new ServerAddress("localhost", 27017),new ServerAddress("localhost", 27018)); // instance.mongoClient = new MongoClient(listHost); // 大部分用户使用mongodb都在安全内网下，但如果将mongodb设为安全验证模式，就需要在客户端提供用户名和密码： // boolean auth = db.authenticate(myUserName, myPassword); Builder options = new MongoClientOptions.Builder(); // options.autoConnectRetry(true);// 自动重连true // options.maxAutoConnectRetryTime(10); // the maximum auto connect retry time options.connectionsPerHost(300);// 连接池设置为300个连接,默认为100 options.connectTimeout(15000);// 连接超时，推荐>3000毫秒 options.maxWaitTime(5000); // options.socketTimeout(0);// 套接字超时时间，0无限制 options.threadsAllowedToBlockForConnectionMultiplier(5000);// 线程队列数，如果连接线程排满了队列就会抛出“Out of semaphores to get db”错误。 options.writeConcern(WriteConcern.SAFE);// options.build(); } // ------------------------------------共用方法--------------------------------------------------- /** * 获取DB实例 - 指定DB * * @param dbName * @return */ public MongoDatabase getDB(String dbName) { if (dbName != null && !"".equals(dbName)) { MongoDatabase database = mongoClient.getDatabase(dbName); return database; } return null; } /** * 获取collection对象 - 指定Collection * * @param collName * @return */ public MongoCollection<Document> getCollection(String dbName, String collName) { if (null == collName || "".equals(collName)) { return null; } if (null == dbName || "".equals(dbName)) { return null; } MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName); return collection; } /** * 查询DB下的所有表名 */ public List<String> getAllCollections(String dbName) { MongoIterable<String> colls = getDB(dbName).listCollectionNames(); List<String> _list = new ArrayList<String>(); for (String s : colls) { _list.add(s); } return _list; } /** * 获取所有数据库名称列表 * * @return */ public MongoIterable<String> getAllDBNames() { MongoIterable<String> s = mongoClient.listDatabaseNames(); return s; } /** * 删除一个数据库 */ public void dropDB(String dbName) { getDB(dbName).drop(); } /** * 查找对象 - 根据主键_id * * @param collection * @param id * @return */ public Document findById(MongoCollection<Document> coll, String id) { ObjectId _idobj = null; try { _idobj = new ObjectId(id); } catch (Exception e) { return null; } Document myDoc = coll.find(Filters.eq("_id", _idobj)).first(); return myDoc; } /** 统计数 */ public int getCount(MongoCollection<Document> coll) { int count = (int) coll.count(); return count; } /** 条件查询 */ public MongoCursor<Document> find(MongoCollection<Document> coll, Bson filter) { return coll.find(filter).iterator(); } /** 分页查询 */ public MongoCursor<Document> findByPage(MongoCollection<Document> coll, Bson filter, int pageNo, int pageSize) { Bson orderBy = new BasicDBObject("_id", 1); return coll.find(filter).sort(orderBy).skip((pageNo - 1) * pageSize).limit(pageSize).iterator(); } /** * 通过ID删除 * * @param coll * @param id * @return */ public int deleteById(MongoCollection<Document> coll, String id) { int count = 0; ObjectId _id = null; try { _id = new ObjectId(id); } catch (Exception e) { return 0; } Bson filter = Filters.eq("_id", _id); DeleteResult deleteResult = coll.deleteOne(filter); count = (int) deleteResult.getDeletedCount(); return count; } /** * FIXME * * @param coll * @param id * @param newdoc * @return */ public Document updateById(MongoCollection<Document> coll, String id, Document newdoc) { ObjectId _idobj = null; try { _idobj = new ObjectId(id); } catch (Exception e) { return null; } Bson filter = Filters.eq("_id", _idobj); // coll.replaceOne(filter, newdoc); // 完全替代 coll.updateOne(filter, new Document("$set", newdoc)); return newdoc; } public void dropCollection(String dbName, String collName) { getDB(dbName).getCollection(collName).drop(); } /** * 关闭Mongodb */ public void close() { if (mongoClient != null) { mongoClient.close(); mongoClient = null; } } /** * 测试入口 * * @param args */ public static void main(String[] args) { String dbName = "GC_MAP_DISPLAY_DB"; String collName = "COMMUNITY_BJ"; MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName); // 插入多条 // for (int i = 1; i <= 4; i++) { // Document doc = new Document(); // doc.put("name", "zhoulf"); // doc.put("school", "NEFU" + i); // Document interests = new Document(); // interests.put("game", "game" + i); // interests.put("ball", "ball" + i); // doc.put("interests", interests); // coll.insertOne(doc); // } // // 根据ID查询 // String id = "556925f34711371df0ddfd4b"; // Document doc = MongoDBUtil2.instance.findById(coll, id); // System.out.println(doc); // 查询多个 // MongoCursor<Document> cursor1 = coll.find(Filters.eq("name", "zhoulf")).iterator(); // while (cursor1.hasNext()) { // org.bson.Document _doc = (Document) cursor1.next(); // System.out.println(_doc.toString()); // } // cursor1.close(); // 查询多个 // MongoCursor<Person> cursor2 = coll.find(Person.class).iterator(); // 删除数据库 // MongoDBUtil2.instance.dropDB("testdb"); // 删除表 // MongoDBUtil2.instance.dropCollection(dbName, collName); // 修改数据 // String id = "556949504711371c60601b5a"; // Document newdoc = new Document(); // newdoc.put("name", "时候"); // MongoDBUtil.instance.updateById(coll, id, newdoc); // 统计表 // System.out.println(MongoDBUtil.instance.getCount(coll)); // 查询所有 Bson filter = Filters.eq("count", 0); MongoDBUtil.instance.find(coll, filter); } }