/* * The MIT License * Copyright © 2014-2019 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.iluwatar.featuretoggle; import com.iluwatar.featuretoggle.pattern.Service; import com.iluwatar.featuretoggle.pattern.propertiesversion.PropertiesFeatureToggleVersion; import com.iluwatar.featuretoggle.pattern.tieredversion.TieredFeatureToggleVersion; import com.iluwatar.featuretoggle.user.User; import com.iluwatar.featuretoggle.user.UserGroup; import java.util.Properties; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * The Feature Toggle pattern allows for complete code executions to be turned on or off with ease. * This allows features to be controlled by either dynamic methods just as {@link User} information * or by {@link Properties}. In the App below there are two examples. Firstly the {@link Properties} * version of the feature toggle, where the enhanced version of the welcome message which is * personalised is turned either on or off at instance creation. This method is not as dynamic as * the {@link User} driven version where the feature of the personalised welcome message is * dependant on the {@link UserGroup} the {@link User} is in. So if the user is a memeber of the * {@link UserGroup#isPaid(User)} then they get an ehanced version of the welcome message. * *
Note that this pattern can easily introduce code complexity, and if not kept in check can * result in redundant unmaintained code within the codebase. */ public class App { private static final Logger LOGGER = LoggerFactory.getLogger(App.class); /** * Block 1 shows the {@link PropertiesFeatureToggleVersion} being run with {@link Properties} * setting the feature toggle to enabled. * *
Block 2 shows the {@link PropertiesFeatureToggleVersion} being run with {@link Properties} * setting the feature toggle to disabled. Notice the difference with the printed welcome message * the username is not included. * *
Block 3 shows the {@link * com.iluwatar.featuretoggle.pattern.tieredversion.TieredFeatureToggleVersion} being set up with * two users on who is on the free level, while the other is on the paid level. When the {@link * Service#getWelcomeMessage(User)} is called with the paid {@link User} note that the welcome * message contains their username, while the same service call with the free tier user is more * generic. No username is printed. * * @see User * @see UserGroup * @see Service * @see PropertiesFeatureToggleVersion * @see com.iluwatar.featuretoggle.pattern.tieredversion.TieredFeatureToggleVersion */ public static void main(String[] args) { final var properties = new Properties(); properties.put("enhancedWelcome", true); var service = new PropertiesFeatureToggleVersion(properties); final var welcomeMessage = service.getWelcomeMessage(new User("Jamie No Code")); LOGGER.info(welcomeMessage); // --------------------------------------------- final var turnedOff = new Properties(); turnedOff.put("enhancedWelcome", false); var turnedOffService = new PropertiesFeatureToggleVersion(turnedOff); final var welcomeMessageturnedOff = turnedOffService.getWelcomeMessage(new User("Jamie No Code")); LOGGER.info(welcomeMessageturnedOff); // -------------------------------------------- var service2 = new TieredFeatureToggleVersion(); final var paidUser = new User("Jamie Coder"); final var freeUser = new User("Alan Defect"); UserGroup.addUserToPaidGroup(paidUser); UserGroup.addUserToFreeGroup(freeUser); final var welcomeMessagePaidUser = service2.getWelcomeMessage(paidUser); final var welcomeMessageFreeUser = service2.getWelcomeMessage(freeUser); LOGGER.info(welcomeMessageFreeUser); LOGGER.info(welcomeMessagePaidUser); } }