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);
}

}