1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.configuration2;
19
20 import java.util.Iterator;
21 import java.util.List;
22 import java.util.Map;
23 import java.util.Properties;
24
25 import org.apache.commons.configuration2.convert.ListDelimiterHandler;
26 import org.apache.commons.lang3.StringUtils;
27
28 /**
29 * Configuration converter. Helper class to convert between Configuration, ExtendedProperties and standard Properties.
30 */
31 public final class ConfigurationConverter {
32 /** Constant for the default separator for properties with multiple values. */
33 private static final char DEFAULT_SEPARATOR = ',';
34
35 /**
36 * Private constructor prevents instances from being created.
37 */
38 private ConfigurationConverter() {
39 // to prevent instantiation
40 }
41
42 /**
43 * Convert a standard Properties class into a configuration class.
44 *
45 * @param props properties object to convert
46 * @return Configuration configuration created from the Properties
47 */
48 public static Configuration getConfiguration(final Properties props) {
49 return new MapConfiguration(props);
50 }
51
52 /**
53 * Convert a Configuration class into a Properties class. List properties are joined into a string using either the list
54 * delimiter handler of the configuration (if it extends AbstractConfiguration) or with a comma as delimiter otherwise.
55 *
56 * @param config ImmutableConfiguration object to convert
57 * @return Properties created from the Configuration
58 * @since 2.2
59 */
60 public static Properties getProperties(final ImmutableConfiguration config) {
61 final Properties props = new Properties();
62 final ListDelimiterHandler listHandler;
63 boolean useDelimiterHandler;
64
65 if (config instanceof AbstractConfiguration) {
66 listHandler = ((AbstractConfiguration) config).getListDelimiterHandler();
67 useDelimiterHandler = true;
68 } else {
69 listHandler = null;
70 useDelimiterHandler = false;
71 }
72
73 for (final Iterator<String> keys = config.getKeys(); keys.hasNext();) {
74 final String key = keys.next();
75 final List<Object> list = config.getList(key);
76
77 String propValue;
78 if (useDelimiterHandler) {
79 try {
80 propValue = String.valueOf(listHandler.escapeList(list, ListDelimiterHandler.NOOP_TRANSFORMER));
81 } catch (final Exception ex) {
82 // obviously, the list handler does not support splitting
83 useDelimiterHandler = false;
84 propValue = listToString(list);
85 }
86 } else {
87 propValue = listToString(list);
88 }
89
90 props.setProperty(key, propValue);
91 }
92
93 return props;
94 }
95
96 /**
97 * Convert a Configuration class into a Properties class. List properties are joined into a string using either the list
98 * delimiter handler of the configuration (if it extends AbstractConfiguration) or with a comma as delimiter otherwise.
99 * 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 }