Java tutorial
/* * //****************************************************************** * // * // Copyright 2016 Samsung Electronics All Rights Reserved. * // * //-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= * // * // Licensed under the Apache License, Version 2.0 (the "License"); * // you may not use this file except in compliance with the License. * // You may obtain a copy of the License at * // * // http://www.apache.org/licenses/LICENSE-2.0 * // * // Unless required by applicable law or agreed to in writing, software * // distributed under the License is distributed on an "AS IS" BASIS, * // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * // See the License for the specific language governing permissions and * // limitations under the License. * // * //-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= */ package org.iotivity.cloud.rdserver.db; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import org.bson.Document; import org.iotivity.cloud.util.Log; import com.mongodb.MongoClient; import com.mongodb.client.MongoCollection; import com.mongodb.client.MongoCursor; import com.mongodb.client.MongoDatabase; import com.mongodb.client.model.IndexOptions; /** * * This class provides a set of APIs to use MongoDB APIs. * */ public class MongoDB { private MongoClient mongoClient = null; private MongoDatabase db = null; /** * API creating MongoClient and initializing MongoDatabase * * @param dbname * database name to create MongoDatabase * @throws Exception */ public MongoDB(String dbname) throws Exception { mongoClient = new MongoClient(); mongoClient.dropDatabase(dbname); db = mongoClient.getDatabase(dbname); } /** * API for creating collection * * @param tableName * collection name */ public void createTable(String tableName) { db.createCollection(tableName); } /** * API for creating index * * @param tableName * collection name * @param keys * key fields of collection */ public void createIndex(String tablename, ArrayList<String> keys) { Document doc = new Document(); for (String key : keys) { doc.append(key, 1); } IndexOptions options = new IndexOptions(); options.unique(true); db.getCollection(tablename).createIndex(doc, options); } /** * API for deleting collection * * @param tableName * collection name */ public void deleteTable(String tableName) { db.getCollection(tableName).drop(); } /** * API for getting database object * */ public MongoDatabase getMongoDatabase() { return db; } /** * API for inserting a record into DB table. the record will not be inserted * if duplicated one. * * @param tableName * table name to be inserted * @param doc * document to be inserted */ public Boolean insertRecord(String tableName, Document doc) { if (tableName == null || doc == null) return false; MongoCollection<Document> collection = db.getCollection(tableName); try { if (collection.find(doc).first() == null) { collection.insertOne(doc); } else { Log.w("DB insert failed due to duplecated one."); return false; } } catch (Exception e) { e.printStackTrace(); return false; } showRecord(tableName); return true; } /** * API for inserting a record into DB table. the record will be replaced if * duplicated one. * * @param tableName * table name to be inserted * @param filter * document filter * @param doc * document to be inserted * @return returns true if the record is inserted and replaced successfully, * or returns false */ public Boolean insertAndReplaceRecord(String tableName, Document filter, Document doc) { if (tableName == null || filter == null || doc == null) return false; MongoCollection<Document> collection = db.getCollection(tableName); try { if (collection.findOneAndReplace(filter, doc) == null) { collection.insertOne(doc); } } catch (Exception e) { e.printStackTrace(); return false; } showRecord(tableName); return true; } /** * API for updating a record into DB table. * * @param tableName * table name to be updated * @param filter * document filter * @param record * record to be updated * @return returns true if the record is updated successfully, or returns * false */ public Boolean updateRecord(String tableName, Document filter, Document record) { if (tableName == null || filter == null || record == null) return false; MongoCollection<Document> collection = db.getCollection(tableName); if (collection.findOneAndReplace(filter, record) == null) { Log.w("DB update failed due to no matched record!"); return false; } showRecord(tableName); return true; } /** * API for deleting records from DB table. * * @param tableName * table name for the record to be deleted * @param record * record filter to be deleted * @return returns true if the record is deleted successfully, or returns * false */ public Boolean deleteRecord(String tableName, Document record) { if (tableName == null || record == null) return false; MongoCollection<Document> collection = db.getCollection(tableName); try { collection.deleteMany(record); } catch (Exception e) { e.printStackTrace(); return false; } showRecord(tableName); return true; } /** * API for selecting records from DB table. * * @param tableName * table name for the record to be selected * @param doc * document filter to be selected * @return record list according to the filter document */ public ArrayList<HashMap<String, Object>> selectRecord(String tableName, Document doc) { if (tableName == null || doc == null) return null; MongoCollection<Document> collection = db.getCollection(tableName); MongoCursor<Document> cursor = collection.find(doc).iterator(); ArrayList<HashMap<String, Object>> recordList = new ArrayList<>(); try { while (cursor.hasNext()) { Document selectedDoc = cursor.next(); recordList.add(convertDocumentToHashMap(selectedDoc)); } } finally { cursor.close(); } return recordList; } private HashMap<String, Object> convertDocumentToHashMap(Document doc) { HashMap<String, Object> resourceMap = new HashMap<>(); Set<Entry<String, Object>> entrySet = doc.entrySet(); Iterator<Entry<String, Object>> entryIter = entrySet.iterator(); while (entryIter.hasNext()) { Map.Entry<String, Object> entry = (Map.Entry<String, Object>) entryIter.next(); String entryKey = entry.getKey(); // remove a mongoDB index if (entry.getValue() != null && !entryKey.equals("_id")) { resourceMap.put(entry.getKey(), entry.getValue()); } } return resourceMap; } private void showRecord(String tableName) { MongoCollection<Document> collection = db.getCollection(tableName); MongoCursor<Document> cursor = collection.find().iterator(); Log.i("<" + tableName + ">"); HashMap<String, Object> records = null; int index = 0; while (cursor.hasNext()) { Document doc = cursor.next(); records = convertDocumentToHashMap(doc); Log.i("[" + index + "] " + records.toString()); index++; } cursor.close(); } }