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);
    }

}