001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.configuration2; 019 020import java.util.Iterator; 021import java.util.List; 022import java.util.Map; 023import java.util.Properties; 024 025import org.apache.commons.configuration2.convert.ListDelimiterHandler; 026import org.apache.commons.lang3.StringUtils; 027 028/** 029 * Configuration converter. Helper class to convert between Configuration, ExtendedProperties and standard Properties. 030 */ 031public final class ConfigurationConverter { 032 /** Constant for the default separator for properties with multiple values. */ 033 private static final char DEFAULT_SEPARATOR = ','; 034 035 /** 036 * Private constructor prevents instances from being created. 037 */ 038 private ConfigurationConverter() { 039 // to prevent instantiation 040 } 041 042 /** 043 * Convert a standard Properties class into a configuration class. 044 * 045 * @param props properties object to convert 046 * @return Configuration configuration created from the Properties 047 */ 048 public static Configuration getConfiguration(final Properties props) { 049 return new MapConfiguration(props); 050 } 051 052 /** 053 * Convert a Configuration class into a Properties class. List properties are joined into a string using either the list 054 * delimiter handler of the configuration (if it extends AbstractConfiguration) or with a comma as delimiter otherwise. 055 * 056 * @param config ImmutableConfiguration object to convert 057 * @return Properties created from the Configuration 058 * @since 2.2 059 */ 060 public static Properties getProperties(final ImmutableConfiguration config) { 061 final Properties props = new Properties(); 062 final ListDelimiterHandler listHandler; 063 boolean useDelimiterHandler; 064 065 if (config instanceof AbstractConfiguration) { 066 listHandler = ((AbstractConfiguration) config).getListDelimiterHandler(); 067 useDelimiterHandler = true; 068 } else { 069 listHandler = null; 070 useDelimiterHandler = false; 071 } 072 073 for (final Iterator<String> keys = config.getKeys(); keys.hasNext();) { 074 final String key = keys.next(); 075 final List<Object> list = config.getList(key); 076 077 String propValue; 078 if (useDelimiterHandler) { 079 try { 080 propValue = String.valueOf(listHandler.escapeList(list, ListDelimiterHandler.NOOP_TRANSFORMER)); 081 } catch (final Exception ex) { 082 // obviously, the list handler does not support splitting 083 useDelimiterHandler = false; 084 propValue = listToString(list); 085 } 086 } else { 087 propValue = listToString(list); 088 } 089 090 props.setProperty(key, propValue); 091 } 092 093 return props; 094 } 095 096 /** 097 * Convert a Configuration class into a Properties class. List properties are joined into a string using either the list 098 * delimiter handler of the configuration (if it extends AbstractConfiguration) or with a comma as delimiter otherwise. 099 * This version of the method exists only for backwards compatibility reason. 100 * 101 * @param config Configuration object to convert 102 * @return Properties created from the Configuration 103 */ 104 public static Properties getProperties(final Configuration config) { 105 return getProperties((ImmutableConfiguration) config); 106 } 107 108 /** 109 * Convert a Configuration class into a Map class. 110 * 111 * @param config Configuration object to convert 112 * @return Map created from the Configuration 113 */ 114 public static Map<Object, Object> getMap(final Configuration config) { 115 return new ConfigurationMap(config); 116 } 117 118 /** 119 * Helper method for joining all elements of a list to a string using the default value separator. 120 * 121 * @param list the list 122 * @return the resulting string 123 */ 124 private static String listToString(final List<?> list) { 125 return StringUtils.join(list, DEFAULT_SEPARATOR); 126 } 127}