Java tutorial
/******************************************************************************* * Copyright (c) 2013 hangum. * All rights reserved. This program and the accompanying materials * are made available under the terms of the GNU Lesser Public License v2.1 * which accompanies this distribution, and is available at * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html * * Contributors: * hangum - initial API and implementation ******************************************************************************/ package com.hangum.tadpole.mongodb.core.query; import java.io.File; import java.io.InputStream; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Set; import java.util.regex.Pattern; import org.apache.commons.io.IOUtils; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Logger; import org.bson.types.ObjectId; import com.hangum.tadpole.engine.query.dao.mongodb.CollectionFieldDAO; import com.hangum.tadpole.engine.query.dao.mongodb.MongoDBIndexDAO; import com.hangum.tadpole.engine.query.dao.mongodb.MongoDBIndexFieldDAO; import com.hangum.tadpole.engine.query.dao.mongodb.MongoDBServerSideJavaScriptDAO; import com.hangum.tadpole.engine.query.dao.mysql.TableDAO; import com.hangum.tadpole.engine.query.dao.system.UserDBDAO; import com.hangum.tadpole.mongodb.core.connection.MongoConnectionManager; import com.hangum.tadpole.mongodb.core.define.MongoDBDefine; import com.hangum.tadpole.mongodb.core.utils.MongoDBTableColumn; import com.mongodb.BasicDBObject; import com.mongodb.CommandResult; import com.mongodb.DB; import com.mongodb.DBCollection; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.Mongo; import com.mongodb.MongoClient; import com.mongodb.WriteResult; import com.mongodb.client.MongoDatabase; import com.mongodb.gridfs.GridFS; import com.mongodb.gridfs.GridFSDBFile; import com.mongodb.gridfs.GridFSInputFile; import com.mongodb.util.JSON; /** * mongodb query * * @author hangum * */ public class MongoDBQuery { /** * Logger for this class */ private static final Logger logger = Logger.getLogger(MongoDBQuery.class); /** * create database * * @param userDB * @throws Exception */ public static void createDB(UserDBDAO userDB) throws Exception { // MongoOptions options = new MongoOptions(); // options.connectionsPerHost = 20; MongoClient mongo = new MongoClient(userDB.getHost(), Integer.parseInt(userDB.getPort())); MongoDatabase db = mongo.getDatabase(userDB.getDb()); // db.authenticate(userDB.getUsers(), userDB.getPasswd().toCharArray()); // // ? ? ? ?? . db.getName();//CollectionNames(); // for (String stringColName : listColNames) {} // } /** * get admin mongodb * * @param userDB * @return * @throws Exception */ public static DB getAdminMongoDB(UserDBDAO userDB) throws Exception { Mongo mongo = new Mongo(userDB.getHost(), Integer.parseInt(userDB.getPort())); return mongo.getDB("admin"); } /** * collection list * * System collections(http://docs.mongodb.org/manual/reference/system-collections/)? collection list . * * * @param userDB * @return * @throws Exception */ public static List<TableDAO> listCollection(UserDBDAO userDB) throws Exception { List<TableDAO> listReturn = new ArrayList<TableDAO>(); DB mongoDB = MongoConnectionManager.getInstance(userDB); for (String col : mongoDB.getCollectionNames()) { if (!isSystemCollection(col)) { TableDAO dao = new TableDAO(); dao.setName(col); CommandResult commandResult = mongoDB.getCollection(col).getStats(); dao.setRows(commandResult.getLong("count")); dao.setSize(commandResult.getInt("size")); listReturn.add(dao); } } return filter(userDB, listReturn); } /** * Execute command * * @param userDB * @param cmd * @return * @throws Exception */ public static CommandResult runCommand(UserDBDAO userDB, String cmd) throws Exception { DB mongoDB = MongoConnectionManager.getInstance(userDB); DBObject cmdObj = (DBObject) JSON.parse(cmd); return mongoDB.command(cmdObj); } /** * ? filter ?. * * @param userDB * @param listDAO */ public static List<TableDAO> filter(UserDBDAO userDB, List<TableDAO> listDAO) { // if("YES".equals(userDB.getIs_table_filter())){ // List<TableDAO> tmpShowTables = new ArrayList<TableDAO>(); // String includeFilter = userDB.getTable_filter_include(); // if("".equals(includeFilter)) { // tmpShowTables.addAll(listDAO); // } else { // for (TableDAO tableDao : listDAO) { // String[] strArryFilters = StringUtils.split(userDB.getTable_filter_include(), ","); // for (String strFilter : strArryFilters) { // if(tableDao.getName().matches(strFilter)) { // tmpShowTables.add(tableDao); // } // } // } // } // // String excludeFilter = userDB.getTable_filter_exclude(); // if(!"".equals(excludeFilter)) { // for (TableDAO tableDao : tmpShowTables) { // String[] strArryFilters = StringUtils.split(userDB.getTable_filter_exclude(), ","); // for (String strFilter : strArryFilters) { // if(tableDao.getName().matches(strFilter)) { // tmpShowTables.remove(tableDao); // } // } // } // } // // return tmpShowTables; // } return listDAO; } /** * collection column list * * @param userDB * @param colName * @return * @throws Exception */ public static List<CollectionFieldDAO> collectionColumn(UserDBDAO userDB, String colName) throws Exception { DB mongoDB = MongoConnectionManager.getInstance(userDB); DBCollection coll = mongoDB.getCollection(colName); return MongoDBTableColumn.tableColumnInfo(coll.getIndexInfo(), coll.findOne()); } /** * collection drop * * @param userDB * @param colName * @throws Exception */ public static void dropCollection(UserDBDAO userDB, String colName) throws Exception { DB mongoDB = MongoConnectionManager.getInstance(userDB); mongoDB.getCollection(colName).drop(); } /** * collection . * * @param userDB * @param collName * @return * @throws Exception */ public static DBCollection findCollection(UserDBDAO userDB, String collName) throws Exception { DB mongoDB = MongoConnectionManager.getInstance(userDB); return mongoDB.getCollection(collName); } /** * findAndModify * * @param userDB * @param collName * @param objQuery * @param objSort * @param isRemove * @param objUpdate * @param isReturnNew * @param objFields * @param isUpsert * @return * @throws Exception */ public static DBObject findAndModify(UserDBDAO userDB, String collName, DBObject objQuery, DBObject objSort, DBObject objFields, boolean isRemove, DBObject objUpdate, boolean isReturnNew, boolean isUpsert) throws Exception { DBCollection coll = findCollection(userDB, collName); DBObject retDBObject = coll.findAndModify(objQuery, objFields, objSort, isRemove, objUpdate, isReturnNew, isUpsert); return retDBObject; } /** * db . * * @param userDB * @return * @throws Exception */ public static DB findDB(UserDBDAO userDB) throws Exception { return MongoConnectionManager.getInstance(userDB); } /** * exist on delete * * @param userDB * @param colName * @throws Exception */ public static void existOnDelete(UserDBDAO userDB, String colName) throws Exception { if (findDB(userDB).collectionExists(colName)) { dropCollection(userDB, colName); } } /** * collection ?. * * @param userDB * @param colName * @param jsonStr * @throws Exception */ public static void createCollection(UserDBDAO userDB, String colName, String jsonStr) throws Exception { DB mongoDB = MongoConnectionManager.getInstance(userDB); DBObject dbObject = (DBObject) JSON.parse(jsonStr); mongoDB.createCollection(colName, dbObject); } /** * objectid find document * * @param userDB * @param colName * @param objectId * @throws Exception */ public static DBObject findDocument(UserDBDAO userDB, String colName, String objectId) throws Exception { DBCollection collection = findCollection(userDB, colName); DBObject queryObj = new BasicDBObject("_id", new ObjectId(objectId)); return collection.findOne(queryObj); } // /** // * explain // * // * @param userDB // * @param colName // * @param jsonStr // * @return // * @throws Exception // */ // public static String explain(UserDBDAO userDB, String colName, String jsonStr) throws Exception { // DBCollection collection = findCollection(userDB, colName); // DBObject dbObject = (DBObject) JSON.parse(jsonStr); // // DBObject explainDBObject = collection.find(dbObject).explain(); // return JSONUtil.getPretty(explainDBObject.toString()); // } // // /** // * find query // * // * @param userDB // * @param colName // * @param jsonStr // * @return // * @throws Exception // */ // public static DBCursor findQuery(UserDBDAO userDB, String colName, String jsonStr) throws Exception { // DBCollection collection = findCollection(userDB, colName); // DBObject dbObject = (DBObject) JSON.parse(jsonStr); // // return collection.find(dbObject); // } /** * insert document * * @param userDB * @param colName * @param jsonStr * @throws Exception */ public static void insertDocument(UserDBDAO userDB, String colName, String jsonStr) throws Exception { DBObject dbObject = (DBObject) JSON.parse(jsonStr); DBCollection collection = findCollection(userDB, colName); WriteResult wr = collection.insert(dbObject); // ? ?? ?(????????????????????????????????) // if(logger.isDebugEnabled()) { // logger.debug( "[writer document]" + wr.toString() ); // logger.debug( wr.getError() ); // logger.debug("[n]" + wr.getN() ); // } } /** * insert document * * @param userDB * @param colName * @param dbObject * @throws Exception */ public static void insertDocument(UserDBDAO userDB, String colName, List<DBObject> dbObject) throws Exception { if (dbObject.size() == 0) return; DBCollection collection = findCollection(userDB, colName); WriteResult wr = collection.insert(dbObject); if (logger.isDebugEnabled()) { try { logger.debug("[writer document]" + wr != null ? wr.toString() : ""); // logger.debug( "[wr error]" + wr!=null?wr.getError():"" ); logger.debug("[n]" + wr != null ? wr.getN() : ""); } catch (Exception e) { logger.error("insert document", e); } } } /** * delete document * * @param userDB * @param colName * @param objectId * @throws Exception */ public static void deleteDocument(UserDBDAO userDB, String colName, DBObject dbObject) throws Exception { DBCollection collection = findCollection(userDB, colName); WriteResult wr = collection.remove(dbObject); if (logger.isDebugEnabled()) { logger.debug("[writer document]" + wr.toString()); // logger.debug( wr.getError() ); logger.debug("[n]" + wr.getN()); } // // ? // if(wr.getN() == 0 && !"".equals(wr.getError())) { // throw new Exception(wr.getError()); // } } /** * update document * * @param userDB * @param colName * @param dBObject * @param key * @param value * @throws Exception */ public static void updateDocument(UserDBDAO userDB, String colName, DBObject dBObject, String key, String value) throws Exception { DBCollection collection = findCollection(userDB, colName); if (logger.isDebugEnabled()) { logger.debug("[dBObject] \t " + dBObject); logger.debug("===============================[key]\t " + key + "\t [value]\t" + value); } BasicDBObject updateQuery = new BasicDBObject().append("$set", new BasicDBObject().append(key, value)); // BasicDBObject newDocument3 = new BasicDBObject().append("$set", new BasicDBObject().append("allPlans.0.cursor", "t2est")); collection.update(dBObject, updateQuery); } /** * create index * * @param userDB * @param colName * @param strIndexName * @param jsonStr * @param unique */ public static void crateIndex(UserDBDAO userDB, String colName, String strIndexName, String jsonStr, boolean unique) throws Exception { DBObject dbObject = (DBObject) JSON.parse(jsonStr); DBCollection collection = findCollection(userDB, colName); collection.createIndex(dbObject, strIndexName, unique); } /** * rename collection * * @param userDB * @param originalName * @param newName * @throws Exception */ public static void renameCollection(UserDBDAO userDB, String originalName, String newName) throws Exception { DBCollection collection = findCollection(userDB, originalName); collection.rename(newName, true); } /** * coll stats * * @param userDB * @param colName * @return * @throws Exception */ public static String getCollStats(UserDBDAO userDB, String colName) throws Exception { DBCollection collection = findCollection(userDB, colName); CommandResult cr = collection.getStats(); if (cr.ok()) { return cr.toString(); } else { throw cr.getException(); } } /** * collection validate * * @param userDB * @param collName * @param isFull * @return * @throws Exception */ public static BasicDBObject collValidate(UserDBDAO userDB, String collName, boolean isFull) throws Exception { DBObject queryObj = new BasicDBObject("validate", collName); queryObj.put("full", isFull); CommandResult cr = findDB(userDB).command(queryObj); if (!cr.ok()) throw cr.getException(); if (logger.isDebugEnabled()) logger.debug("[compact] complements" + cr.toString()); return (BasicDBObject) cr; } /** * collection compact * * @param userDB * @param colName * @param force * @param paddingFactor * @param paddingBytes * @return * @throws Exception */ public static String collCompact(UserDBDAO userDB, String colName, boolean isForct, int paddingFactor, int paddingBytes) throws Exception { DB mongoDB = findDB(userDB); DBObject queryObj = new BasicDBObject("compact", colName); if (paddingFactor > 0) queryObj.put("paddingFactor", paddingFactor); if (paddingBytes > 0) queryObj.put("paddingBytes", paddingBytes); CommandResult cr = mongoDB.command(queryObj); if (!cr.ok()) throw cr.getException(); if (logger.isDebugEnabled()) logger.debug("[compact] complements" + cr.toString()); return cr.toString(); } /** * reIndex collection * * @param userDB * @param colName * @throws Exception */ public static void reIndexCollection(UserDBDAO userDB, String colName) throws Exception { DB mongoDB = findDB(userDB); DBObject queryObj = new BasicDBObject("reIndex", colName); CommandResult cr = mongoDB.command(queryObj); if (!cr.ok()) throw cr.getException(); if (logger.isDebugEnabled()) logger.debug("[reIndex] complements" + colName); } /** * list index * * @param userDB * @throws Exception */ public static List<MongoDBIndexDAO> listAllIndex(UserDBDAO userDB) throws Exception { List<MongoDBIndexDAO> listReturnIndex = new ArrayList<MongoDBIndexDAO>(); DB mongoDB = MongoConnectionManager.getInstance(userDB); for (String col : mongoDB.getCollectionNames()) { if (!isSystemCollection(col)) { List<DBObject> listIndexObj = mongoDB.getCollection(col).getIndexInfo(); for (DBObject dbObject : listIndexObj) { MongoDBIndexDAO indexDao = new MongoDBIndexDAO(); indexDao.setV(dbObject.get("v").toString()); Map<String, Object> objMap = (Map) dbObject.get("key"); for (String strKey : objMap.keySet()) { indexDao.getListIndexField() .add(new MongoDBIndexFieldDAO(strKey, objMap.get(strKey).toString())); } if (dbObject.containsField("unique")) { indexDao.setUnique(Boolean.valueOf(dbObject.get("unique").toString())); } String strNs = dbObject.get("ns").toString(); strNs = StringUtils.substringAfter(strNs, userDB.getDb() + "."); indexDao.setNs(strNs); indexDao.setName(dbObject.get("name").toString()); listReturnIndex.add(indexDao); } } } return listReturnIndex; } /** * all Server Side Java Script * @param userDB * @throws Exception */ public static List<MongoDBServerSideJavaScriptDAO> listAllJavaScript(UserDBDAO userDB) throws Exception { List<MongoDBServerSideJavaScriptDAO> listReturn = new ArrayList<MongoDBServerSideJavaScriptDAO>(); DBCursor dbCursor = findDB(userDB).getCollection("system.js").find(); List<DBObject> lsitCursor = dbCursor.toArray(); for (DBObject dbObject : lsitCursor) { listReturn.add(new MongoDBServerSideJavaScriptDAO(dbObject.get("_id").toString(), dbObject.get("value").toString())); } return listReturn; } /** * save java script * * @param userDB * @param javaScriptDAO * @throws Exception */ public static void insertJavaScript(UserDBDAO userDB, MongoDBServerSideJavaScriptDAO javaScriptDAO) throws Exception { DBObject dbObject = (DBObject) JSON .parse("{'_id':'" + javaScriptDAO.getName() + "', 'value':'" + javaScriptDAO.getContent() + "'}"); findCollection(userDB, "system.js").save(dbObject); } /** * update java script * * @param userDB * @param _id * @param content * @throws Exception */ public static void updateJavaScript(UserDBDAO userDB, String _id, String content) throws Exception { DBObject dbFindObject = (DBObject) JSON.parse("{'_id':'" + _id + "'}"); DBObject dbUpdateObject = (DBObject) JSON.parse("{'_id':'" + _id + "', 'value':'" + content + "'}"); findCollection(userDB, "system.js").findAndModify(dbFindObject, dbUpdateObject); } /** * remove javascript * * @param userDB * @param _id * @throws Exception */ public static void deleteJavaScirpt(UserDBDAO userDB, String _id) throws Exception { DBObject dbFindObject = (DBObject) JSON.parse("{'_id':'" + _id + "'}"); findCollection(userDB, "system.js").remove(dbFindObject); } /** * execute eval * * @param userDB * @param content * @param inputArray * @return * @throws Exception */ public static Object executeEval(UserDBDAO userDB, String content, Object[] inputArray) throws Exception { Object dbObject = findDB(userDB).eval(content, inputArray); return dbObject; } /** * is system collection * @param colName * @return */ public static boolean isSystemCollection(String colName) { for (String sysColl : MongoDBDefine.SYSTEM_COLLECTION) { if (colName.equals(sysColl)) return true; } return false; } /** * Server status, return to String * * @param userDB * @throws Exception */ public static String serverStatus(UserDBDAO userDB) throws Exception { DB mongoDB = findDB(userDB); DBObject queryObj = new BasicDBObject("serverStatus", 1); CommandResult cr = mongoDB.command(queryObj); if (cr.ok()) { return cr.toString(); } else { throw cr.getException(); } } /** * Server status return to CommandResult * * @param userDB * @throws Exception */ public static CommandResult serverStatusCommandResult(UserDBDAO userDB) throws Exception { DB mongoDB = findDB(userDB); DBObject queryObj = new BasicDBObject("serverStatus", 1); return mongoDB.command(queryObj); } /** * top * * @param userDB * @param top * @return * @throws Exception */ public static String top(UserDBDAO userDB, int top) throws Exception { UserDBDAO adminDB = new UserDBDAO(); adminDB.setHost(userDB.getHost()); adminDB.setPort(userDB.getPort()); adminDB.setUsers(userDB.getUsers()); adminDB.setPasswd(userDB.getPasswd()); adminDB.setUrl(userDB.getHost() + ":" + userDB.getPort() + "/admin"); adminDB.setDb("admin"); DB mongoDB = findDB(adminDB); DBObject queryObj = new BasicDBObject("top", top); CommandResult cr = mongoDB.command(queryObj); if (cr.ok()) { return cr.toString(); } else { logger.error("top command" + userDB, cr.getException()); throw new Exception(cr.getErrorMessage());//cr.getException(); } } /** * mongodb web console * * @param userDB * @return */ public static String webConsole(UserDBDAO userDB) throws Exception { return "http://" + userDB.getHost() + ":" + (Integer.parseInt(userDB.getPort()) + 1000); } /** * db stats * * @param userDB * @throws Exception */ public static String dbStats(UserDBDAO userDB) throws Exception { DB mongoDB = findDB(userDB); CommandResult cr = mongoDB.getStats(); if (cr.ok()) { return cr.toString(); } else { throw cr.getException(); } } /** * collection exist * * @param userDB * @param collName * @return * @throws Exception */ public static boolean collectionExist(UserDBDAO userDB, String collName) throws Exception { DB mongoDB = findDB(userDB); return mongoDB.collectionExists(collName); } /** * profiling start * @param userDB * @param level 0 : stop, 1 or 2 : start * @return * @throws Exception */ public static boolean commandProfiling(UserDBDAO userDB, int level) throws Exception { DB mongoDB = findDB(userDB); DBObject queryObj = new BasicDBObject("profile", level); CommandResult cr = mongoDB.command(queryObj); if (cr.ok()) { return true; } else { throw cr.getException(); } } /** * currentOp * * @param userDB * @return * @throws Excepiton */ public static DBObject currentOp(UserDBDAO userDB) throws Exception { DB mongoDb = findDB(userDB); DBObject dbObj = (DBObject) mongoDb.eval("db.currentOp()"); return dbObj; } /** * killOp * * @param userDB * @param opId * @throws Exception */ public static void killOp(UserDBDAO userDB, String opId) throws Exception { DB mongoDb = findDB(userDB); DBObject dbObj = (DBObject) mongoDb.eval("db.killOp(" + opId + ")"); if (logger.isDebugEnabled()) logger.debug("[killOp] " + dbObj); } /** * user . * * @param userDB * @param id * @param passwd * @param isReadOnly * @throws Exception */ public static void addUser(UserDBDAO userDB, String id, String passwd, boolean isReadOnly) throws Exception { DB mongoDb = findDB(userDB); WriteResult wr = mongoDb.addUser(id, passwd.toCharArray(), isReadOnly); } /** * ? * * @param userDB * @throws Exception */ public static DBCursor getUser(UserDBDAO userDB) throws Exception { DB mongoDb = findDB(userDB); return mongoDb.getCollection("system.users").find(); } /** * ? . * @param userDB * @param id * @throws Exception */ public static void deleteUser(UserDBDAO userDB, String id) throws Exception { DBCollection collection = findCollection(userDB, "system.users"); DBObject query = new BasicDBObject("user", id); WriteResult wr = collection.remove(query); } /** * gridFS * * @param userDB * @param strBucket * @param strFileName * @param intSkip * @param intLimit * @return * @throws Exception */ public static DBCursor getGridFS(UserDBDAO userDB, String strBucket, String strFileName, int intSkip, int intLimit) throws Exception { DB mongoDb = findDB(userDB); GridFS gridFs = null; if ("".equals(strBucket)) gridFs = new GridFS(mongoDb); else gridFs = new GridFS(mongoDb, strBucket); if ("".equals(strFileName)) { return gridFs.getFileList().skip(intSkip).limit(intLimit); } else { DBObject queryObj = new BasicDBObject(); Pattern regex = Pattern.compile(".*" + strFileName + "*"); queryObj.put("filename", regex); return gridFs.getFileList(queryObj).skip(intSkip).limit(intLimit); } } /** * bucket list . * * @param userDB * @return * @throws Exception */ public static List<String> getGridFSBucketList(UserDBDAO userDB) throws Exception { List<String> listStr = new ArrayList<String>(); DB mongoDb = findDB(userDB); Set<String> colNames = mongoDb.getCollectionNames(); for (String name : colNames) { if (StringUtils.contains(name, ".chunks")) listStr.add(StringUtils.removeEnd(name, ".chunks")); } return listStr; } /** * GridFS chunck detail information * * @param userDB * @param objectId * @return * @throws Exception */ public static DBCursor getGridFSChunckDetail(UserDBDAO userDB, String searchChunkName, String objectId) throws Exception { DBCollection col = findCollection(userDB, searchChunkName); // DBObject queryObj = new BasicDBObject(); queryObj.put("files_id", new ObjectId(objectId)); // field DBObject fieldObj = new BasicDBObject(); fieldObj.put("files_id", 1); fieldObj.put("n", 1); return col.find(queryObj, fieldObj); } /** * get gridfs data * * @param userDB * @param _id * @return * @throws Exception */ public static byte[] getGridFS(UserDBDAO userDB, String strBucket, String _id) throws Exception { DB mongoDb = findDB(userDB); GridFS gridFs = null; if ("".equals(strBucket)) gridFs = new GridFS(mongoDb); else gridFs = new GridFS(mongoDb, strBucket); GridFSDBFile gridFSFile = gridFs.findOne(new ObjectId(_id)); InputStream is = gridFSFile.getInputStream(); return IOUtils.toByteArray(is); } /** * delte gridfs * * @param userDB * @param _id * @throws Exception */ public static void dleteGridFs(UserDBDAO userDB, String strBucket, String _id) throws Exception { DB mongoDb = findDB(userDB); GridFS gridFs = null; if ("".equals(strBucket)) gridFs = new GridFS(mongoDb); else gridFs = new GridFS(mongoDb, strBucket); gridFs.remove(gridFs.findOne(new ObjectId(_id))); } /** * insert gridfs * * @param userDB * @param strBucket * @param fileList * @throws Exception */ public static void insertGridFS(UserDBDAO userDB, String strBucket, List<String> fileList) throws Exception { DB mongoDb = findDB(userDB); GridFS gridFs = null; if ("".equals(strBucket)) gridFs = new GridFS(mongoDb); else gridFs = new GridFS(mongoDb, strBucket); for (String strFile : fileList) { String saveFileName = strFile.substring(strFile.lastIndexOf(File.separator) + 1); GridFSInputFile gfsFile = gridFs.createFile(new File(strFile)); gfsFile.setFilename(saveFileName); gfsFile.save(); } } /** * index . * * @param userDB * @param name */ public static void dropIndex(UserDBDAO userDB, String colName, String name) throws Exception { findCollection(userDB, colName).dropIndex(name); } }