一个简单的MongoDB操作类

import java.net.UnknownHostException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.WriteResult;
import com.mongodb.util.JSON;

/**
 * MongoDB操作类
 * @author dyk
 *
 */
public class MongoDbManagerImpl implements MongoDbManager{
	protected static Logger logger = LoggerFactory.getLogger("03046");
	private static final String DBNAME = "clementine";
	private Mongo mongo = null;
	private DB dbConnection = null;
	private String mongoServerAddr;
	private int mongoServerPort;
	private static Map<String, DBCollection> dbCollectionMap = new ConcurrentHashMap<String, DBCollection>();
	
	public void setMongoServerAddr(String mongoServerAddr) {
		this.mongoServerAddr = mongoServerAddr;
	}
	public void setMongoServerPort(int mongoServerPort) {
		this.mongoServerPort = mongoServerPort;
	}
	public void init() {
		if (this.mongo == null) {
			try {
				this.mongo = new Mongo( this.mongoServerAddr , this.mongoServerPort);
				if (null != this.mongo) {
					this.dbConnection = this.mongo.getDB(DBNAME);
				}
			} catch (UnknownHostException e) {
				logger.error("连接mongoDb失败, 服务器地址: " + this.mongoServerAddr + ", 端口: " + this.mongoServerPort);
				throw new RuntimeException(e);
			}
		}
	}
	
	/**
	 * get an table 
	 * @param collectionName
	 * @return
	 */
	private DBCollection getDBCollection(String collectionName) {
		DBCollection collection = null;
		if (dbCollectionMap.containsKey(collectionName)) {
			collection = dbCollectionMap.get(collectionName);
		} else {
			collection = this.dbConnection.getCollection(collectionName);
			if (null != collection) {
				dbCollectionMap.put(collectionName, collection);
			}
		}
		return collection;
	}
	
	/**
	 * check if doc exsit
	 * @param collectionName table name
	 * @param query target document
	 */
	@Override
	public boolean isDocumentExsit(String collectionName, DBObject query) {
		boolean result = false;
		DBCursor dbCursor = null;
		DBCollection collection = this.getDBCollection(collectionName);
		if (null != collection) {
			dbCursor = collection.find(query);
			if (null != dbCursor && dbCursor.hasNext()) {
				result = true;
			}
		}
		return result;
	}
	/**
	 * query an record
	 * @param collectionName table name
	 * @param query target document
	 * @return
	 */
	@Override
	public DBObject selectDocument(String collectionName, DBObject query) {
		DBObject result = null;
		DBCursor dbCursor = null;
		DBCollection collection = this.getDBCollection(collectionName);
		if (null != collection) {
			dbCursor = collection.find(query);
			if (null != dbCursor && dbCursor.hasNext()) {
				result = dbCursor.next();
			}
		}
		return result;
	}

	/**
	 * 	/**
	 * insert an new record
	 * @param collectionName table name
	 * @param newDocument new doc
	 * @param query target document
	 */
	@Override
	public void insertDocument(String collectionName, DBObject newDocument) {
		DBCollection collection = this.getDBCollection(collectionName);
		if (null != collection) {
			if (!this.isDocumentExsit(collectionName, newDocument)) {//insert only doc not exist 
				collection.insert(newDocument);
			}
		}
	}
	
	/**
	 * update an document
	 * @param collectionName
	 * @param query target document
	 * @param updatedDocument
	 * @return
	 */
	@Override
	public boolean updateDocument(String collectionName, DBObject query, DBObject updatedDocument) {
		boolean result = false;
		WriteResult writeResult = null;
		DBCollection collection = this.getDBCollection(collectionName);
		if (null != collection) {
			writeResult = collection.update(query, updatedDocument);
			if (null != writeResult) {
				if (writeResult.getN() > 0) {
					result = true;
				}
			}
		}
		return result;
	}
	
	/**
	 * delete an document
	 * @param collectionName
	 * @param document target document
	 * @return
	 */
	@Override
	public boolean deleteDocument(String collectionName, DBObject query) {
		boolean result = false;
		WriteResult writeResult = null;
		DBCollection collection = this.getDBCollection(collectionName);
		if (null != collection) {
			writeResult = collection.remove(query);
			if (null != writeResult) {
				if (writeResult.getN() > 0) {
					result = true;
				}
			}
		}
		return result;
	}
	
	public static void main(String[] args) throws UnknownHostException {
		MongoDbManagerImpl m = new MongoDbManagerImpl();
		m.setMongoServerAddr("10.235.164.180");
		m.setMongoServerPort(27017);
		m.init();
		String collectionName = "myTest";
		
		//insert
		String json ="{'num' : 1}";
		DBObject doc1 =(DBObject)JSON.parse(json);
		m.insertDocument(collectionName, doc1);
		
		//select
		DBObject doc2 = null;
		DBObject query = new BasicDBObject();
		query.put("num", 1);
		doc2 = m.selectDocument(collectionName, query);
		
		System.out.println(doc2);

		//update
		DBObject updatedDocument = new BasicDBObject();
		updatedDocument.put("$set", new BasicDBObject().append("num", 100));
		boolean result = m.updateDocument(collectionName, query, updatedDocument);
		System.out.println(result);
		query.put("num", 100);
//		//remove
		result = m.deleteDocument(collectionName, query);
		System.out.println(result);
	}

}