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 * https://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.Objects;
22
23 import org.apache.commons.configuration2.ex.ConfigurationException;
24 import org.apache.commons.configuration2.io.FileHandler;
25 import org.apache.commons.logging.Log;
26 import org.apache.commons.logging.LogFactory;
27
28 /**
29 * A configuration based on the system properties.
30 *
31 * @since 1.1
32 */
33 public class SystemConfiguration extends MapConfiguration {
34 /** The logger. */
35 private static final Log LOG = LogFactory.getLog(SystemConfiguration.class);
36
37 /**
38 * Sets System properties from a configuration object.
39 *
40 * @param systemConfig The configuration containing the properties to be set.
41 * @since 1.6
42 */
43 public static void setSystemProperties(final Configuration systemConfig) {
44 systemConfig.forEach((k, v) -> {
45 if (LOG.isDebugEnabled()) {
46 LOG.debug("Setting system property " + k + " to " + v);
47 }
48 System.setProperty(k, Objects.toString(v, null));
49 });
50 }
51
52 /**
53 * Sets system properties from a file specified by its file name. This is just a short cut for
54 * {@code setSystemProperties(null, fileName)}.
55 *
56 * @param fileName The name of the property file.
57 * @throws ConfigurationException if an error occurs.
58 * @since 1.6
59 */
60 public static void setSystemProperties(final String fileName) throws ConfigurationException {
61 setSystemProperties(null, fileName);
62 }
63
64 /**
65 * Sets system properties from a file specified using its base path and file name. The file can either be a properties
66 * file or an XML properties file. It is loaded, and all properties it contains are added to system properties.
67 *
68 * @param basePath The base path to look for the property file.
69 * @param fileName The name of the property file.
70 * @throws ConfigurationException if an error occurs.
71 * @since 1.6
72 */
73 public static void setSystemProperties(final String basePath, final String fileName) throws ConfigurationException {
74 final FileBasedConfiguration config = fileName.endsWith(".xml") ? new XMLPropertiesConfiguration() : new PropertiesConfiguration();
75 final FileHandler handler = new FileHandler(config);
76 handler.setBasePath(basePath);
77 handler.setFileName(fileName);
78 handler.load();
79 setSystemProperties(config);
80 }
81
82 /**
83 * Create a Configuration based on the system properties.
84 *
85 * @see System#getProperties
86 */
87 public SystemConfiguration() {
88 super(System.getProperties());
89 }
90
91 /**
92 * {@inheritDoc} This implementation returns a snapshot of the keys in the system properties. If another thread modifies
93 * system properties concurrently, these changes are not reflected by the iterator returned by this method.
94 */
95 @Override
96 protected Iterator<String> getKeysInternal() {
97 return System.getProperties().stringPropertyNames().iterator();
98 }
99 }