DatabaseUtilities.java

/*
 * Copyright IBM Corp. 2015
 *
 * 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 net.bluemix.droneselfie;

import org.ektorp.CouchDbConnector;
import org.ektorp.CouchDbInstance;
import org.ektorp.http.HttpClient;
import org.ektorp.http.StdHttpClient;
import org.ektorp.impl.StdCouchDbInstance;
import org.apache.wink.json4j.JSON;
import org.apache.wink.json4j.JSONArray;
import org.apache.wink.json4j.JSONObject;

public class DatabaseUtilities {

	private DatabaseUtilities() {
	}

	private static DatabaseUtilities singleton;
	private CouchDbConnector db;

	static public DatabaseUtilities getSingleton() {
		if (singleton == null) {
			singleton = new DatabaseUtilities();
		}
		return singleton;
	}

	public CouchDbConnector getDB() {

		if (db != null)
			return db;

		boolean configExists = false;
		String host = null;
		String username = null;
		String password = null;

		try {
			String db_url = System.getenv("DS_DB_HOST");
			String db_user = System.getenv("DS_DB_USERNAME");
			String db_pw = System.getenv("DS_DB_PASSWORD");	
			
			if ((db_url != null) && (!db_url.equalsIgnoreCase(""))
					&& (db_user != null) && (!db_user.equalsIgnoreCase(""))
					&& (db_pw != null) && (!db_pw.equalsIgnoreCase(""))) {

				host = db_url;
				username = db_user;
				password = db_pw;

				configExists = true;
			} else {
				String VCAP_SERVICES = System.getenv("VCAP_SERVICES");

				if (VCAP_SERVICES != null) {
					Object jsonObject = JSON.parse(VCAP_SERVICES);
					JSONObject json = (JSONObject) jsonObject;
					String key = null;
					JSONArray list = null;
					java.util.Set<String> keys = json.keySet();
					for (String eachkey : keys) {
						if (eachkey.contains("cloudantNoSQLDB")) {
							key = eachkey;
							break;
						}
					}
					if (key == null) {
						return null;
					}
					list = (JSONArray) json.get(key);
					JSONObject jsonService = (JSONObject) list.get(0);
					JSONObject credentials = (JSONObject) jsonService
							.get("credentials");

					host = (String) credentials.get("host");
					username = (String) credentials.get("username");
					password = (String) credentials.get("password");

					configExists = true;
				}
			}
			if (configExists) {
				HttpClient httpClient;

				httpClient = new StdHttpClient.Builder()
						.url("https://" + host + "/drone-selfie")
						.username(username).password(password).build();

				CouchDbInstance dbInstance = new StdCouchDbInstance(httpClient);

				db = dbInstance.createConnector("drone-selfie", true);

				db.createDatabaseIfNotExists();
				DatabaseDesign.createDesign(db);

				return db;
			} else {
				return null;
			}
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
}