Java tutorial
/* * Copyright 2014-2015 Cask Data, Inc. * * 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 co.cask.cdap.ui; import ch.qos.logback.classic.Level; import ch.qos.logback.classic.Logger; import ch.qos.logback.classic.LoggerContext; import co.cask.cdap.common.conf.CConfiguration; import co.cask.cdap.common.conf.Configuration; import co.cask.cdap.common.conf.SConfiguration; import com.google.common.collect.Maps; import com.google.common.collect.Sets; import com.google.gson.GsonBuilder; import org.slf4j.ILoggerFactory; import org.slf4j.LoggerFactory; import java.util.Map; import java.util.Set; /** * A tool to save the CConfiguration as Json. */ public class ConfigurationJsonTool { private static final String CDAP_CONFIG = "--cdap"; private static final String SECURITY_CONFIG = "--security"; private static void exportToJson(String configParam, Appendable output) { Configuration config; if (configParam.equals(CDAP_CONFIG)) { config = CConfiguration.create(); } else if (configParam.equals(SECURITY_CONFIG)) { config = SConfiguration.create(); } else { return; } exportToJson(config, output); } public static void exportToJson(Configuration configuration, Appendable output) { // Set the log-level of the Configuration logger to ERROR. We don't want warning of deprecated key. Level oldLevel = setConfigurationLogLevel(Level.ERROR); Map<String, String> map = Maps.newHashMapWithExpectedSize(configuration.size()); for (Map.Entry<String, String> entry : configuration) { map.put(entry.getKey(), entry.getValue()); } new GsonBuilder().setPrettyPrinting().create().toJson(map, output); // Restore the log level setConfigurationLogLevel(oldLevel); } public static void main(String[] args) { String programName = System.getProperty("script", "ConfigurationJsonTool"); Set<String> validArgument = Sets.newHashSet(); validArgument.add(CDAP_CONFIG); validArgument.add(SECURITY_CONFIG); if (args.length != 1 || !(validArgument.contains(args[0]))) { System.err.println(String.format("Usage: %s (%s | %s)", programName, CDAP_CONFIG, SECURITY_CONFIG)); System.exit(1); } exportToJson(args[0], System.out); } /** * Sets the logger level of the {@link Configuration} object. The log level is only set if the logger is a * logback logger. * * @param level Level to set to. * @return The current log level or {@code null} if the logger is not a logback logger. */ private static Level setConfigurationLogLevel(Level level) { ILoggerFactory loggerFactory = LoggerFactory.getILoggerFactory(); if (loggerFactory instanceof LoggerContext) { Logger logger = ((LoggerContext) loggerFactory).getLogger(Configuration.class); Level oldLevel = logger.getLevel(); logger.setLevel(level); return oldLevel; } return null; } }