Java tutorial
/* * This file is part of Bitsquare. * * Bitsquare is free software: you can redistribute it and/or modify it * under the terms of the GNU Affero General Public License as published by * the Free Software Foundation, either version 3 of the License, or (at * your option) any later version. * * Bitsquare is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public * License for more details. * * You should have received a copy of the GNU Affero General Public License * along with Bitsquare. If not, see <http://www.gnu.org/licenses/>. */ package io.bitsquare.app; import joptsimple.OptionException; import joptsimple.OptionParser; import joptsimple.OptionSet; import org.springframework.util.StringUtils; import static java.lang.String.format; import static java.lang.String.join; public abstract class BitsquareExecutable { public static final int EXIT_SUCCESS = 0; public static final int EXIT_FAILURE = 1; public static final String HELP_KEY = "help"; public void execute(String[] args) throws Exception { OptionParser parser = new OptionParser(); parser.accepts(HELP_KEY, "This help text").forHelp(); this.customizeOptionParsing(parser); OptionSet options; try { options = parser.parse(args); if (options.has(HELP_KEY)) { parser.printHelpOn(System.out); System.exit(EXIT_SUCCESS); return; } } catch (OptionException ex) { System.out.println("error: " + ex.getMessage()); System.out.println(); parser.printHelpOn(System.out); System.exit(EXIT_FAILURE); return; } this.doExecute(options); } protected abstract void customizeOptionParsing(OptionParser parser); protected static String description(String descText, Object defaultValue) { String description = ""; if (StringUtils.hasText(descText)) description = description.concat(descText); if (defaultValue != null) description = join(" ", description, format("(default: %s)", defaultValue)); return description; } protected abstract void doExecute(OptionSet options); }