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
35 /** The logger. */
36 private static final Log LOG = LogFactory.getLog(SystemConfiguration.class);
37
38 /**
39 * Sets System properties from a configuration object.
40 *
41 * @param systemConfig The configuration containing the properties to be set.
42 * @since 1.6
43 */
44 public static void setSystemProperties(final Configuration systemConfig) {
45 systemConfig.forEach((k, v) -> {
46 if (LOG.isDebugEnabled()) {
47 LOG.debug("Setting system property " + k + " to " + v);
48 }
49 System.setProperty(k, Objects.toString(v, null));
50 });
51 }
52
53 /**
54 * Sets system properties from a file specified by its file name. This is just a short cut for
55 * {@code setSystemProperties(null, fileName)}.
56 *
57 * @param fileName The name of the property file.
58 * @throws ConfigurationException if an error occurs.
59 * @since 1.6
60 */
61 public static void setSystemProperties(final String fileName) throws ConfigurationException {
62 setSystemProperties(null, fileName);
63 }
64
65 /**
66 * Sets system properties from a file specified using its base path and file name. The file can either be a properties
67 * file or an XML properties file. It is loaded, and all properties it contains are added to system properties.
68 *
69 * @param basePath The base path to look for the property file.
70 * @param fileName The name of the property file.
71 * @throws ConfigurationException if an error occurs.
72 * @since 1.6
73 */
74 public static void setSystemProperties(final String basePath, final String fileName) throws ConfigurationException {
75 final FileBasedConfiguration config = fileName.endsWith(".xml") ? new XMLPropertiesConfiguration() : new PropertiesConfiguration();
76 final FileHandler handler = new FileHandler(config);
77 handler.setBasePath(basePath);
78 handler.setFileName(fileName);
79 handler.load();
80 setSystemProperties(config);
81 }
82
83 /**
84 * Create a Configuration based on the system properties.
85 *
86 * @see System#getProperties
87 */
88 public SystemConfiguration() {
89 super(System.getProperties());
90 }
91
92 /**
93 * {@inheritDoc} This implementation returns a snapshot of the keys in the system properties. If another thread modifies
94 * system properties concurrently, these changes are not reflected by the iterator returned by this method.
95 */
96 @Override
97 protected Iterator<String> getKeysInternal() {
98 return System.getProperties().stringPropertyNames().iterator();
99 }
100 }