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 package org.apache.commons.text.lookup;
18
19 import java.util.Locale;
20
21 import org.apache.commons.lang3.StringUtils;
22 import org.apache.commons.text.StringSubstitutor;
23
24 /**
25 * Looks up keys related to Java: Java version, JRE version, VM version, and so on.
26 * <p>
27 * The lookup keys with examples are:
28 * </p>
29 * <ul>
30 * <li><strong>version</strong>: "Java version 1.8.0_181"</li>
31 * <li><strong>runtime</strong>: "Java(TM) SE Runtime Environment (build 1.8.0_181-b13) from Oracle Corporation"</li>
32 * <li><strong>vm</strong>: "Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)"</li>
33 * <li><strong>os</strong>: "Windows 10 10.0, architecture: amd64-64"</li>
34 * <li><strong>hardware</strong>: "processors: 4, architecture: amd64-64, instruction sets: amd64"</li>
35 * <li><strong>locale</strong>: "default locale: en_US, platform encoding: iso-8859-1"</li>
36 * </ul>
37 *
38 * <p>
39 * Using a {@link StringLookup} from the {@link StringLookupFactory}:
40 * </p>
41 *
42 * <pre>
43 * StringLookupFactory.INSTANCE.javaPlatformStringLookup().lookup("version");
44 * </pre>
45 * <p>
46 * Using a {@link StringSubstitutor}:
47 * </p>
48 *
49 * <pre>
50 * StringSubstitutor.createInterpolator().replace("... ${java:version} ..."));
51 * </pre>
52 * <p>
53 * The above examples convert {@code "version"} to the current VM version, for example,
54 * {@code "Java version 1.8.0_181"}.
55 * </p>
56 *
57 * @since 1.3
58 */
59 final class JavaPlatformStringLookup extends AbstractStringLookup {
60
61 /**
62 * Defines the singleton for this class.
63 */
64 static final JavaPlatformStringLookup INSTANCE = new JavaPlatformStringLookup();
65 /** {@code hardware} key for driving {@link JavaPlatformStringLookup#lookup(String)}. */
66 private static final String KEY_HARDWARE = "hardware";
67 /** {@code locale} key for driving {@link JavaPlatformStringLookup#lookup(String)}. */
68 private static final String KEY_LOCALE = "locale";
69 /** {@code os} key for driving {@link JavaPlatformStringLookup#lookup(String)}. */
70 private static final String KEY_OS = "os";
71 /** {@code runtime} key for driving {@link JavaPlatformStringLookup#lookup(String)}. */
72 private static final String KEY_RUNTIME = "runtime";
73 /** {@code version} key for driving {@link JavaPlatformStringLookup#lookup(String)}. */
74 private static final String KEY_VERSION = "version";
75
76 /** {@code vm} key for driving {@link JavaPlatformStringLookup#lookup(String)}. */
77 private static final String KEY_VM = "vm";
78
79 /**
80 * The main method for running the JavaPlatformStringLookup.
81 *
82 * @param args the standard Java main method parameter which is unused for our running of this class.
83 */
84 public static void main(final String[] args) {
85 System.out.println(JavaPlatformStringLookup.class);
86 System.out.printf("%s = %s%n", KEY_VERSION, JavaPlatformStringLookup.INSTANCE.lookup(KEY_VERSION));
87 System.out.printf("%s = %s%n", KEY_RUNTIME, JavaPlatformStringLookup.INSTANCE.lookup(KEY_RUNTIME));
88 System.out.printf("%s = %s%n", KEY_VM, JavaPlatformStringLookup.INSTANCE.lookup(KEY_VM));
89 System.out.printf("%s = %s%n", KEY_OS, JavaPlatformStringLookup.INSTANCE.lookup(KEY_OS));
90 System.out.printf("%s = %s%n", KEY_HARDWARE, JavaPlatformStringLookup.INSTANCE.lookup(KEY_HARDWARE));
91 System.out.printf("%s = %s%n", KEY_LOCALE, JavaPlatformStringLookup.INSTANCE.lookup(KEY_LOCALE));
92 }
93
94 /**
95 * No need to build instances for now.
96 */
97 private JavaPlatformStringLookup() {
98 // empty
99 }
100
101 /**
102 * Accessible through the Lookup key {@code hardware}.
103 *
104 * @return hardware processor information.
105 */
106 String getHardware() {
107 return "processors: " + Runtime.getRuntime().availableProcessors() + ", architecture: "
108 + getSystemProperty("os.arch") + this.getSystemProperty("-", "sun.arch.data.model")
109 + this.getSystemProperty(", instruction sets: ", "sun.cpu.isalist");
110 }
111
112 /**
113 * Accessible through the Lookup key {@code locale}.
114 *
115 * @return system locale and file encoding information.
116 */
117 String getLocale() {
118 return "default locale: " + Locale.getDefault() + ", platform encoding: " + getSystemProperty("file.encoding");
119 }
120
121 /**
122 * Accessible through the Lookup key {@code os}.
123 *
124 * @return operating system information.
125 */
126 String getOperatingSystem() {
127 return getSystemProperty("os.name") + " " + getSystemProperty("os.version")
128 + getSystemProperty(" ", "sun.os.patch.level") + ", architecture: " + getSystemProperty("os.arch")
129 + getSystemProperty("-", "sun.arch.data.model");
130 }
131
132 /**
133 * Accessible through the Lookup key {@code runtime}.
134 *
135 * @return Java Runtime Environment information.
136 */
137 String getRuntime() {
138 return getSystemProperty("java.runtime.name") + " (build " + getSystemProperty("java.runtime.version")
139 + ") from " + getSystemProperty("java.vendor");
140 }
141
142 /**
143 * Gets the given system property.
144 *
145 * @param name a system property name.
146 * @return a system property value.
147 */
148 private String getSystemProperty(final String name) {
149 return StringLookupFactory.INSTANCE_SYSTEM_PROPERTIES.lookup(name);
150 }
151
152 /**
153 * Gets the given system property.
154 *
155 * @param prefix the prefix to use for the result string
156 * @param name a system property name.
157 * @return The prefix + a system property value.
158 */
159 private String getSystemProperty(final String prefix, final String name) {
160 final String value = getSystemProperty(name);
161 if (StringUtils.isEmpty(value)) {
162 return StringUtils.EMPTY;
163 }
164 return prefix + value;
165 }
166
167 /**
168 * Accessible through the Lookup key {@code vm}.
169 *
170 * @return Java Virtual Machine information.
171 */
172 String getVirtualMachine() {
173 return getSystemProperty("java.vm.name") + " (build " + getSystemProperty("java.vm.version") + ", "
174 + getSystemProperty("java.vm.info") + ")";
175 }
176
177 /**
178 * Looks up the value of the Java platform key.
179 * <p>
180 * The lookup keys with examples are:
181 * </p>
182 * <ul>
183 * <li><strong>version</strong>: "Java version 1.8.0_181"</li>
184 * <li><strong>runtime</strong>: "Java(TM) SE Runtime Environment (build 1.8.0_181-b13) from Oracle Corporation"</li>
185 * <li><strong>vm</strong>: "Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)"</li>
186 * <li><strong>os</strong>: "Windows 10 10.0, architecture: amd64-64"</li>
187 * <li><strong>hardware</strong>: "processors: 4, architecture: amd64-64, instruction sets: amd64"</li>
188 * <li><strong>locale</strong>: "default locale: en_US, platform encoding: iso-8859-1"</li>
189 * </ul>
190 *
191 * @param key the key to be looked up, may be null
192 * @return The value of the environment variable.
193 */
194 @Override
195 public String lookup(final String key) {
196 if (key == null) {
197 return null;
198 }
199 switch (key) {
200 case KEY_VERSION:
201 return "Java version " + getSystemProperty("java.version");
202 case KEY_RUNTIME:
203 return getRuntime();
204 case KEY_VM:
205 return getVirtualMachine();
206 case KEY_OS:
207 return getOperatingSystem();
208 case KEY_HARDWARE:
209 return getHardware();
210 case KEY_LOCALE:
211 return getLocale();
212 default:
213 throw new IllegalArgumentException(key);
214 }
215 }
216 }