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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.lang3;
18  
19  import java.io.File;
20  
21  /**
22   * Helpers for {@link System}.
23   *
24   * <p>
25   * If a system property cannot be read due to security restrictions, the corresponding field in this class will be set
26   * to {@code null} and a message will be written to {@code System.err}.
27   * </p>
28   * <p>
29   * #ThreadSafe#
30   * </p>
31   *
32   * @since 1.0
33   * @see SystemProperties
34   */
35  public class SystemUtils {
36  
37      /**
38       * The prefix String for all Windows OS.
39       */
40      private static final String OS_NAME_WINDOWS_PREFIX = "Windows";
41  
42      // System property constants
43      // -----------------------------------------------------------------------
44      // These MUST be declared first. Other constants depend on this.
45  
46      /**
47       * The {@code file.encoding} System Property.
48       *
49       * <p>
50       * File encoding, such as {@code Cp1252}.
51       * </p>
52       * <p>
53       * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
54       * not exist.
55       * </p>
56       * <p>
57       * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
58       * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
59       * sync with that System property.
60       * </p>
61       *
62       * @see SystemProperties#getFileEncoding()
63       * @since 2.0
64       * @since Java 1.2
65       */
66      public static final String FILE_ENCODING = SystemProperties.getFileEncoding();
67  
68      /**
69       * The {@code file.separator} System Property.
70       * The file separator is:
71       *
72       * <ul>
73       * <li>{@code "/"} on UNIX</li>
74       * <li>{@code "\"} on Windows.</li>
75       * </ul>
76       *
77       * <p>
78       * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
79       * not exist.
80       * </p>
81       * <p>
82       * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
83       * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
84       * sync with that System property.
85       * </p>
86       *
87       * @see SystemProperties#getFileSeparator()
88       * @deprecated Use {@link File#separator}, since it is guaranteed to be a
89       *             string containing a single character and it does not require a privilege check.
90       * @since Java 1.1
91       */
92      @Deprecated
93      public static final String FILE_SEPARATOR = SystemProperties.getFileSeparator();
94  
95      /**
96       * The {@code java.awt.fonts} System Property.
97       *
98       * <p>
99       * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
100      * not exist.
101      * </p>
102      * <p>
103      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
104      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
105      * sync with that System property.
106      * </p>
107      *
108      * @see SystemProperties#getJavaAwtFonts()
109      * @since 2.1
110      */
111     public static final String JAVA_AWT_FONTS = SystemProperties.getJavaAwtFonts();
112 
113     /**
114      * The {@code java.awt.graphicsenv} System Property.
115      *
116      * <p>
117      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
118      * not exist.
119      * </p>
120      * <p>
121      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
122      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
123      * sync with that System property.
124      * </p>
125      *
126      * @see SystemProperties#getJavaAwtGraphicsenv()
127      * @since 2.1
128      */
129     public static final String JAVA_AWT_GRAPHICSENV = SystemProperties.getJavaAwtGraphicsenv();
130 
131     /**
132      * The {@code java.awt.headless} System Property. The value of this property is the String {@code "true"} or
133      * {@code "false"}.
134      *
135      * <p>
136      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
137      * not exist.
138      * </p>
139      * <p>
140      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
141      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
142      * sync with that System property.
143      * </p>
144      *
145      * @see #isJavaAwtHeadless()
146      * @see SystemProperties#getJavaAwtHeadless()
147      * @since 2.1
148      * @since Java 1.4
149      */
150     public static final String JAVA_AWT_HEADLESS = SystemProperties.getJavaAwtHeadless();
151 
152     /**
153      * The {@code java.awt.printerjob} System Property.
154      *
155      * <p>
156      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
157      * not exist.
158      * </p>
159      * <p>
160      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
161      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
162      * sync with that System property.
163      * </p>
164      *
165      * @see SystemProperties#getJavaAwtPrinterjob()
166      * @since 2.1
167      */
168     public static final String JAVA_AWT_PRINTERJOB = SystemProperties.getJavaAwtPrinterjob();
169 
170     /**
171      * The {@code java.class.path} System Property. Java class path.
172      *
173      * <p>
174      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
175      * not exist.
176      * </p>
177      * <p>
178      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
179      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
180      * sync with that System property.
181      * </p>
182      *
183      * @see SystemProperties#getJavaClassPath()
184      * @since Java 1.1
185      */
186     public static final String JAVA_CLASS_PATH = SystemProperties.getJavaClassPath();
187 
188     /**
189      * The {@code java.class.version} System Property. Java class format version number.
190      *
191      * <p>
192      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
193      * not exist.
194      * </p>
195      * <p>
196      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
197      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
198      * sync with that System property.
199      * </p>
200      *
201      * @see SystemProperties#getJavaClassVersion()
202      * @since Java 1.1
203      */
204     public static final String JAVA_CLASS_VERSION = SystemProperties.getJavaClassVersion();
205 
206     /**
207      * The {@code java.compiler} System Property. Name of JIT compiler to use. First in JDK version 1.2. Not used in Sun
208      * JDKs after 1.2.
209      *
210      * <p>
211      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
212      * not exist.
213      * </p>
214      * <p>
215      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
216      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
217      * sync with that System property.
218      * </p>
219      *
220      * @see SystemProperties#getJavaCompiler()
221      * @since Java 1.2. Not used in Sun versions after 1.2.
222      */
223     public static final String JAVA_COMPILER = SystemProperties.getJavaCompiler();
224 
225     /**
226      * The {@code java.endorsed.dirs} System Property. Path of endorsed directory or directories.
227      *
228      * <p>
229      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
230      * not exist.
231      * </p>
232      * <p>
233      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
234      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
235      * sync with that System property.
236      * </p>
237      *
238      * @see SystemProperties#getJavaEndorsedDirs()
239      * @since Java 1.4
240      */
241     public static final String JAVA_ENDORSED_DIRS = SystemProperties.getJavaEndorsedDirs();
242 
243     /**
244      * The {@code java.ext.dirs} System Property. Path of extension directory or directories.
245      *
246      * <p>
247      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
248      * not exist.
249      * </p>
250      * <p>
251      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
252      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
253      * sync with that System property.
254      * </p>
255      *
256      * @see SystemProperties#getJavaExtDirs()
257      * @since Java 1.3
258      */
259     public static final String JAVA_EXT_DIRS = SystemProperties.getJavaExtDirs();
260 
261     /**
262      * The {@code java.home} System Property. Java installation directory.
263      *
264      * <p>
265      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
266      * not exist.
267      * </p>
268      * <p>
269      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
270      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
271      * sync with that System property.
272      * </p>
273      *
274      * @see SystemProperties#getJavaHome()
275      * @since Java 1.1
276      */
277     public static final String JAVA_HOME = SystemProperties.getJavaHome();
278 
279     /**
280      * The {@code java.io.tmpdir} System Property. Default temp file path.
281      *
282      * <p>
283      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
284      * not exist.
285      * </p>
286      * <p>
287      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
288      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
289      * sync with that System property.
290      * </p>
291      *
292      * @see SystemProperties#getJavaIoTmpdir()
293      * @since Java 1.2
294      */
295     public static final String JAVA_IO_TMPDIR = SystemProperties.getJavaIoTmpdir();
296 
297     /**
298      * The {@code java.library.path} System Property. List of paths to search when loading libraries.
299      *
300      * <p>
301      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
302      * not exist.
303      * </p>
304      * <p>
305      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
306      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
307      * sync with that System property.
308      * </p>
309      *
310      * @see SystemProperties#getJavaLibraryPath()
311      * @since Java 1.2
312      */
313     public static final String JAVA_LIBRARY_PATH = SystemProperties.getJavaLibraryPath();
314 
315     /**
316      * The {@code java.runtime.name} System Property. Java Runtime Environment name.
317      *
318      * <p>
319      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
320      * not exist.
321      * </p>
322      * <p>
323      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
324      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
325      * sync with that System property.
326      * </p>
327      *
328      * @see SystemProperties#getJavaRuntimeName()
329      * @since 2.0
330      * @since Java 1.3
331      */
332     public static final String JAVA_RUNTIME_NAME = SystemProperties.getJavaRuntimeName();
333 
334     /**
335      * The {@code java.runtime.version} System Property. Java Runtime Environment version.
336      *
337      * <p>
338      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
339      * not exist.
340      * </p>
341      * <p>
342      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
343      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
344      * sync with that System property.
345      * </p>
346      *
347      * @see SystemProperties#getJavaRuntimeVersion()
348      * @since 2.0
349      * @since Java 1.3
350      */
351     public static final String JAVA_RUNTIME_VERSION = SystemProperties.getJavaRuntimeVersion();
352 
353     /**
354      * The {@code java.specification.name} System Property. Java Runtime Environment specification name.
355      *
356      * <p>
357      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
358      * not exist.
359      * </p>
360      * <p>
361      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
362      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
363      * sync with that System property.
364      * </p>
365      *
366      * @see SystemProperties#getJavaSpecificationName()
367      * @since Java 1.2
368      */
369     public static final String JAVA_SPECIFICATION_NAME = SystemProperties.getJavaSpecificationName();
370 
371     /**
372      * The {@code java.specification.vendor} System Property. Java Runtime Environment specification vendor.
373      *
374      * <p>
375      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
376      * not exist.
377      * </p>
378      * <p>
379      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
380      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
381      * sync with that System property.
382      * </p>
383      *
384      * @see SystemProperties#getJavaSpecificationVendor()
385      * @since Java 1.2
386      */
387     public static final String JAVA_SPECIFICATION_VENDOR = SystemProperties.getJavaSpecificationVendor();
388 
389     /**
390      * The {@code java.specification.version} System Property. Java Runtime Environment specification version.
391      *
392      * <p>
393      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
394      * not exist.
395      * </p>
396      * <p>
397      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
398      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
399      * sync with that System property.
400      * </p>
401      *
402      * @see SystemProperties#getJavaSpecificationVersion()
403      * @since Java 1.3
404      */
405     public static final String JAVA_SPECIFICATION_VERSION = SystemProperties.getJavaSpecificationVersion();
406 
407     private static final JavaVersion JAVA_SPECIFICATION_VERSION_AS_ENUM = JavaVersion.get(JAVA_SPECIFICATION_VERSION);
408 
409     /**
410      * The {@code java.util.prefs.PreferencesFactory} System Property. A class name.
411      *
412      * <p>
413      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
414      * not exist.
415      * </p>
416      * <p>
417      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
418      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
419      * sync with that System property.
420      * </p>
421      *
422      * @see SystemProperties#getJavaUtilPrefsPreferencesFactory()
423      * @since 2.1
424      * @since Java 1.4
425      */
426     public static final String JAVA_UTIL_PREFS_PREFERENCES_FACTORY = SystemProperties.getJavaUtilPrefsPreferencesFactory();
427 
428     /**
429      * The {@code java.vendor} System Property. Java vendor-specific string.
430      *
431      * <p>
432      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
433      * not exist.
434      * </p>
435      * <p>
436      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
437      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
438      * sync with that System property.
439      * </p>
440      *
441      * @see SystemProperties#getJavaVendor()
442      * @since Java 1.1
443      */
444     public static final String JAVA_VENDOR = SystemProperties.getJavaVendor();
445 
446     /**
447      * The {@code java.vendor.url} System Property. Java vendor URL.
448      *
449      * <p>
450      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
451      * not exist.
452      * </p>
453      * <p>
454      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
455      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
456      * sync with that System property.
457      * </p>
458      *
459      * @see SystemProperties#getJavaVendorUrl()
460      * @since Java 1.1
461      */
462     public static final String JAVA_VENDOR_URL = SystemProperties.getJavaVendorUrl();
463 
464     /**
465      * The {@code java.version} System Property. Java version number.
466      *
467      * <p>
468      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
469      * not exist.
470      * </p>
471      * <p>
472      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
473      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
474      * sync with that System property.
475      * </p>
476      *
477      * @see SystemProperties#getJavaVersion()
478      * @since Java 1.1
479      */
480     public static final String JAVA_VERSION = SystemProperties.getJavaVersion();
481 
482     /**
483      * The {@code java.vm.info} System Property. Java Virtual Machine implementation info.
484      *
485      * <p>
486      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
487      * not exist.
488      * </p>
489      * <p>
490      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
491      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
492      * sync with that System property.
493      * </p>
494      *
495      * @see SystemProperties#getJavaVmInfo()
496      * @since 2.0
497      * @since Java 1.2
498      */
499     public static final String JAVA_VM_INFO = SystemProperties.getJavaVmInfo();
500 
501     /**
502      * The {@code java.vm.name} System Property. Java Virtual Machine implementation name.
503      *
504      * <p>
505      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
506      * not exist.
507      * </p>
508      * <p>
509      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
510      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
511      * sync with that System property.
512      * </p>
513      *
514      * @see SystemProperties#getJavaVmName()
515      * @since Java 1.2
516      */
517     public static final String JAVA_VM_NAME = SystemProperties.getJavaVmName();
518 
519     /**
520      * The {@code java.vm.specification.name} System Property. Java Virtual Machine specification name.
521      *
522      * <p>
523      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
524      * not exist.
525      * </p>
526      * <p>
527      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
528      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
529      * sync with that System property.
530      * </p>
531      *
532      * @see SystemProperties#getJavaVmSpecificationName()
533      * @since Java 1.2
534      */
535     public static final String JAVA_VM_SPECIFICATION_NAME = SystemProperties.getJavaVmSpecificationName();
536 
537     /**
538      * The {@code java.vm.specification.vendor} System Property. Java Virtual Machine specification vendor.
539      *
540      * <p>
541      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
542      * not exist.
543      * </p>
544      * <p>
545      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
546      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
547      * sync with that System property.
548      * </p>
549      *
550      * @see SystemProperties#getJavaVmSpecificationVendor()
551      * @since Java 1.2
552      */
553     public static final String JAVA_VM_SPECIFICATION_VENDOR = SystemProperties.getJavaVmSpecificationVendor();
554 
555     /**
556      * The {@code java.vm.specification.version} System Property. Java Virtual Machine specification version.
557      *
558      * <p>
559      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
560      * not exist.
561      * </p>
562      * <p>
563      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
564      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
565      * sync with that System property.
566      * </p>
567      *
568      * @see SystemProperties#getJavaVmSpecificationVersion()
569      * @since Java 1.2
570      */
571     public static final String JAVA_VM_SPECIFICATION_VERSION = SystemProperties.getJavaVmSpecificationVersion();
572 
573     /**
574      * The {@code java.vm.vendor} System Property. Java Virtual Machine implementation vendor.
575      *
576      * <p>
577      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
578      * not exist.
579      * </p>
580      * <p>
581      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
582      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
583      * sync with that System property.
584      * </p>
585      *
586      * @see SystemProperties#getJavaVmVendor()
587      * @since Java 1.2
588      */
589     public static final String JAVA_VM_VENDOR = SystemProperties.getJavaVmVendor();
590 
591     /**
592      * The {@code java.vm.version} System Property. Java Virtual Machine implementation version.
593      *
594      * <p>
595      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
596      * not exist.
597      * </p>
598      * <p>
599      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
600      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
601      * sync with that System property.
602      * </p>
603      *
604      * @see SystemProperties#getJavaVmVersion()
605      * @since Java 1.2
606      */
607     public static final String JAVA_VM_VERSION = SystemProperties.getJavaVmVersion();
608 
609     /**
610      * The {@code line.separator} System Property. Line separator ({@code &quot;\n&quot;} on UNIX).
611      *
612      * <p>
613      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
614      * not exist.
615      * </p>
616      * <p>
617      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
618      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
619      * sync with that System property.
620      * </p>
621      *
622      * @see SystemProperties#getLineSeparator()
623      * @deprecated Use {@link System#lineSeparator()} instead, since it does not require a privilege check.
624      * @since Java 1.1
625      */
626     @Deprecated
627     public static final String LINE_SEPARATOR = SystemProperties.getLineSeparator();
628 
629     /**
630      * The {@code os.arch} System Property. Operating system architecture.
631      *
632      * <p>
633      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
634      * not exist.
635      * </p>
636      * <p>
637      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
638      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
639      * sync with that System property.
640      * </p>
641      *
642      * @see SystemProperties#getOsArch()
643      * @since Java 1.1
644      */
645     public static final String OS_ARCH = SystemProperties.getOsArch();
646 
647     /**
648      * The {@code os.name} System Property. Operating system name.
649      *
650      * <p>
651      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
652      * not exist.
653      * </p>
654      * <p>
655      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
656      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
657      * sync with that System property.
658      * </p>
659      *
660      * @see SystemProperties#getOsName()
661      * @since Java 1.1
662      */
663     public static final String OS_NAME = SystemProperties.getOsName();
664 
665     /**
666      * The {@code os.version} System Property. Operating system version.
667      *
668      * <p>
669      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
670      * not exist.
671      * </p>
672      * <p>
673      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
674      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
675      * sync with that System property.
676      * </p>
677      *
678      * @see SystemProperties#getOsVersion()
679      * @since Java 1.1
680      */
681     public static final String OS_VERSION = SystemProperties.getOsVersion();
682 
683     /**
684      * The {@code path.separator} System Property. Path separator ({@code &quot;:&quot;} on UNIX).
685      *
686      * <p>
687      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
688      * not exist.
689      * </p>
690      * <p>
691      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
692      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
693      * sync with that System property.
694      * </p>
695      *
696      * @see SystemProperties#getPathSeparator()
697      * @deprecated Use {@link File#pathSeparator}, since it is guaranteed to be a
698      *             string containing a single character and it does not require a privilege check.
699      * @since Java 1.1
700      */
701     @Deprecated
702     public static final String PATH_SEPARATOR = SystemProperties.getPathSeparator();
703 
704     /**
705      * The {@code user.country} or {@code user.region} System Property. User's country code, such as {@code "GB"}. First
706      * in Java version 1.2 as {@code user.region}. Renamed to {@code user.country} in 1.4
707      *
708      * <p>
709      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
710      * not exist.
711      * </p>
712      * <p>
713      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
714      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
715      * sync with that System property.
716      * </p>
717      *
718      * @since 2.0
719      * @since Java 1.2
720      */
721     public static final String USER_COUNTRY = SystemProperties.getProperty(SystemProperties.USER_COUNTRY,
722             () -> SystemProperties.getProperty(SystemProperties.USER_REGION));
723 
724     /**
725      * The {@code user.dir} System Property. User's current working directory.
726      *
727      * <p>
728      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
729      * not exist.
730      * </p>
731      * <p>
732      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
733      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
734      * sync with that System property.
735      * </p>
736      *
737      * @see SystemProperties#getUserDir()
738      * @since Java 1.1
739      */
740     public static final String USER_DIR = SystemProperties.getUserDir();
741 
742     /**
743      * The {@code user.home} System Property. User's home directory.
744      *
745      * <p>
746      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
747      * not exist.
748      * </p>
749      * <p>
750      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
751      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
752      * sync with that System property.
753      * </p>
754      *
755      * @see SystemProperties#getUserHome()
756      * @since Java 1.1
757      */
758     public static final String USER_HOME = SystemProperties.getUserHome();
759 
760     /**
761      * The {@code user.language} System Property. User's language code, such as {@code "en"}.
762      *
763      * <p>
764      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
765      * not exist.
766      * </p>
767      * <p>
768      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
769      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
770      * sync with that System property.
771      * </p>
772      *
773      * @see SystemProperties#getUserLanguage()
774      * @since 2.0
775      * @since Java 1.2
776      */
777     public static final String USER_LANGUAGE = SystemProperties.getUserLanguage();
778 
779     /**
780      * The {@code user.name} System Property. User's account name.
781      *
782      * <p>
783      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
784      * not exist.
785      * </p>
786      * <p>
787      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
788      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
789      * sync with that System property.
790      * </p>
791      *
792      * @see SystemProperties#getUserName()
793      * @since Java 1.1
794      */
795     public static final String USER_NAME = SystemProperties.getUserName();
796 
797     /**
798      * The {@code user.timezone} System Property. For example: {@code "America/Los_Angeles"}.
799      *
800      * <p>
801      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
802      * not exist.
803      * </p>
804      * <p>
805      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
806      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
807      * sync with that System property.
808      * </p>
809      *
810      * @see SystemProperties#getUserTimezone()
811      * @since 2.1
812      */
813     public static final String USER_TIMEZONE = SystemProperties.getUserTimezone();
814 
815     // Java version checks
816     // -----------------------------------------------------------------------
817     // These MUST be declared after those above as they depend on the
818     // values being set up
819 
820     /**
821      * Is {@code true} if this is Java version 1.1 (also 1.1.x versions).
822      *
823      * <p>
824      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
825      * </p>
826      * <p>
827      * This value is initialized when the class is loaded.
828      * </p>
829      */
830     public static final boolean IS_JAVA_1_1 = getJavaVersionMatches("1.1");
831 
832     /**
833      * Is {@code true} if this is Java version 1.2 (also 1.2.x versions).
834      *
835      * <p>
836      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
837      * </p>
838      * <p>
839      * This value is initialized when the class is loaded.
840      * </p>
841      */
842     public static final boolean IS_JAVA_1_2 = getJavaVersionMatches("1.2");
843 
844     /**
845      * Is {@code true} if this is Java version 1.3 (also 1.3.x versions).
846      *
847      * <p>
848      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
849      * </p>
850      * <p>
851      * This value is initialized when the class is loaded.
852      * </p>
853      */
854     public static final boolean IS_JAVA_1_3 = getJavaVersionMatches("1.3");
855 
856     /**
857      * Is {@code true} if this is Java version 1.4 (also 1.4.x versions).
858      *
859      * <p>
860      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
861      * </p>
862      * <p>
863      * This value is initialized when the class is loaded.
864      * </p>
865      */
866     public static final boolean IS_JAVA_1_4 = getJavaVersionMatches("1.4");
867 
868     /**
869      * Is {@code true} if this is Java version 1.5 (also 1.5.x versions).
870      *
871      * <p>
872      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
873      * </p>
874      * <p>
875      * This value is initialized when the class is loaded.
876      * </p>
877      */
878     public static final boolean IS_JAVA_1_5 = getJavaVersionMatches("1.5");
879 
880     /**
881      * Is {@code true} if this is Java version 1.6 (also 1.6.x versions).
882      *
883      * <p>
884      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
885      * </p>
886      * <p>
887      * This value is initialized when the class is loaded.
888      * </p>
889      */
890     public static final boolean IS_JAVA_1_6 = getJavaVersionMatches("1.6");
891 
892     /**
893      * Is {@code true} if this is Java version 1.7 (also 1.7.x versions).
894      *
895      * <p>
896      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
897      * </p>
898      * <p>
899      * This value is initialized when the class is loaded.
900      * </p>
901      *
902      * @since 3.0
903      */
904     public static final boolean IS_JAVA_1_7 = getJavaVersionMatches("1.7");
905 
906     /**
907      * Is {@code true} if this is Java version 1.8 (also 1.8.x versions).
908      *
909      * <p>
910      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
911      * </p>
912      * <p>
913      * This value is initialized when the class is loaded.
914      * </p>
915      *
916      * @since 3.3.2
917      */
918     public static final boolean IS_JAVA_1_8 = getJavaVersionMatches("1.8");
919 
920     /**
921      * Is {@code true} if this is Java version 1.9 (also 1.9.x versions).
922      *
923      * <p>
924      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
925      * </p>
926      * <p>
927      * This value is initialized when the class is loaded.
928      * </p>
929      *
930      * @since 3.4
931      *
932      * @deprecated As of release 3.5, replaced by {@link #IS_JAVA_9}
933      */
934     @Deprecated
935     public static final boolean IS_JAVA_1_9 = getJavaVersionMatches("9");
936 
937     /**
938      * Is {@code true} if this is Java version 9 (also 9.x versions).
939      *
940      * <p>
941      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
942      * </p>
943      * <p>
944      * This value is initialized when the class is loaded.
945      * </p>
946      *
947      * @since 3.5
948      */
949     public static final boolean IS_JAVA_9 = getJavaVersionMatches("9");
950 
951     /**
952      * Is {@code true} if this is Java version 10 (also 10.x versions).
953      *
954      * <p>
955      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
956      * </p>
957      * <p>
958      * This value is initialized when the class is loaded.
959      * </p>
960      *
961      * @since 3.7
962      */
963     public static final boolean IS_JAVA_10 = getJavaVersionMatches("10");
964 
965     /**
966      * Is {@code true} if this is Java version 11 (also 11.x versions).
967      *
968      * <p>
969      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
970      * </p>
971      * <p>
972      * This value is initialized when the class is loaded.
973      * </p>
974      *
975      * @since 3.8
976      */
977     public static final boolean IS_JAVA_11 = getJavaVersionMatches("11");
978 
979     /**
980      * Is {@code true} if this is Java version 12 (also 12.x versions).
981      *
982      * <p>
983      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
984      * </p>
985      * <p>
986      * This value is initialized when the class is loaded.
987      * </p>
988      *
989      * @since 3.9
990      */
991     public static final boolean IS_JAVA_12 = getJavaVersionMatches("12");
992 
993     /**
994      * Is {@code true} if this is Java version 13 (also 13.x versions).
995      *
996      * <p>
997      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
998      * </p>
999      * <p>
1000      * This value is initialized when the class is loaded.
1001      * </p>
1002      *
1003      * @since 3.9
1004      */
1005     public static final boolean IS_JAVA_13 = getJavaVersionMatches("13");
1006 
1007     /**
1008      * Is {@code true} if this is Java version 14 (also 14.x versions).
1009      *
1010      * <p>
1011      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1012      * </p>
1013      * <p>
1014      * This value is initialized when the class is loaded.
1015      * </p>
1016      *
1017      * @since 3.10
1018      */
1019     public static final boolean IS_JAVA_14 = getJavaVersionMatches("14");
1020 
1021     /**
1022      * Is {@code true} if this is Java version 15 (also 15.x versions).
1023      *
1024      * <p>
1025      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1026      * </p>
1027      * <p>
1028      * This value is initialized when the class is loaded.
1029      * </p>
1030      *
1031      * @since 3.10
1032      */
1033     public static final boolean IS_JAVA_15 = getJavaVersionMatches("15");
1034 
1035     /**
1036      * Is {@code true} if this is Java version 16 (also 16.x versions).
1037      * <p>
1038      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1039      * </p>
1040      * <p>
1041      * This value is initialized when the class is loaded.
1042      * </p>
1043      *
1044      * @since 3.13.0
1045      */
1046     public static final boolean IS_JAVA_16 = getJavaVersionMatches("16");
1047 
1048     /**
1049      * Is {@code true} if this is Java version 17 (also 17.x versions).
1050      * <p>
1051      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1052      * </p>
1053      * <p>
1054      * This value is initialized when the class is loaded.
1055      * </p>
1056      *
1057      * @since 3.13.0
1058      */
1059     public static final boolean IS_JAVA_17 = getJavaVersionMatches("17");
1060 
1061     /**
1062      * Is {@code true} if this is Java version 18 (also 18.x versions).
1063      * <p>
1064      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1065      * </p>
1066      * <p>
1067      * This value is initialized when the class is loaded.
1068      * </p>
1069      *
1070      * @since 3.13.0
1071      */
1072     public static final boolean IS_JAVA_18 = getJavaVersionMatches("18");
1073 
1074     /**
1075      * Is {@code true} if this is Java version 19 (also 19.x versions).
1076      * <p>
1077      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1078      * </p>
1079      * <p>
1080      * This value is initialized when the class is loaded.
1081      * </p>
1082      *
1083      * @since 3.13.0
1084      */
1085     public static final boolean IS_JAVA_19 = getJavaVersionMatches("19");
1086 
1087     /**
1088      * Is {@code true} if this is Java version 20 (also 20.x versions).
1089      * <p>
1090      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1091      * </p>
1092      * <p>
1093      * This value is initialized when the class is loaded.
1094      * </p>
1095      *
1096      * @since 3.13.0
1097      */
1098     public static final boolean IS_JAVA_20 = getJavaVersionMatches("20");
1099 
1100     /**
1101      * Is {@code true} if this is Java version 21 (also 21.x versions).
1102      * <p>
1103      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1104      * </p>
1105      * <p>
1106      * This value is initialized when the class is loaded.
1107      * </p>
1108      *
1109      * @since 3.13.0
1110      */
1111     public static final boolean IS_JAVA_21 = getJavaVersionMatches("21");
1112 
1113     /**
1114      * Is {@code true} if this is Java version 22 (also 22.x versions).
1115      * <p>
1116      * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
1117      * </p>
1118      * <p>
1119      * This value is initialized when the class is loaded.
1120      * </p>
1121      *
1122      * @since 3.15.0
1123      */
1124     public static final boolean IS_JAVA_22 = getJavaVersionMatches("22");
1125 
1126     // Operating system checks
1127     // -----------------------------------------------------------------------
1128     // These MUST be declared after those above as they depend on the
1129     // values being set up
1130     // Please advise dev@commons.apache.org if you want another added
1131     // or a mistake corrected
1132 
1133     /**
1134      * Is {@code true} if this is AIX.
1135      *
1136      * <p>
1137      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1138      * </p>
1139      * <p>
1140      * This value is initialized when the class is loaded.
1141      * </p>
1142      *
1143      * @since 2.0
1144      */
1145     public static final boolean IS_OS_AIX = getOsMatchesName("AIX");
1146 
1147     /**
1148      * Is {@code true} if this is Android.
1149      *
1150      * <p>
1151      * See https://developer.android.com/reference/java/lang/System#getProperties().
1152      * </p>
1153      * <p>
1154      * This value is initialized when the class is loaded.
1155      * </p>
1156      *
1157      * @since 3.15.0
1158      */
1159     public static final boolean IS_OS_ANDROID = SystemProperties.getJavaVendor().contains("Android");
1160 
1161     /**
1162      * Is {@code true} if this is HP-UX.
1163      *
1164      * <p>
1165      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1166      * </p>
1167      * <p>
1168      * This value is initialized when the class is loaded.
1169      * </p>
1170      *
1171      * @since 2.0
1172      */
1173     public static final boolean IS_OS_HP_UX = getOsMatchesName("HP-UX");
1174 
1175     /**
1176      * Is {@code true} if this is IBM OS/400.
1177      *
1178      * <p>
1179      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1180      * </p>
1181      * <p>
1182      * This value is initialized when the class is loaded.
1183      * </p>
1184      *
1185      * @since 3.3
1186      */
1187     public static final boolean IS_OS_400 = getOsMatchesName("OS/400");
1188 
1189     /**
1190      * Is {@code true} if this is Irix.
1191      *
1192      * <p>
1193      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1194      * </p>
1195      * <p>
1196      * This value is initialized when the class is loaded.
1197      * </p>
1198      *
1199      * @since 2.0
1200      */
1201     public static final boolean IS_OS_IRIX = getOsMatchesName("Irix");
1202 
1203     /**
1204      * Is {@code true} if this is Linux.
1205      *
1206      * <p>
1207      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1208      * </p>
1209      * <p>
1210      * This value is initialized when the class is loaded.
1211      * </p>
1212      *
1213      * @since 2.0
1214      */
1215     public static final boolean IS_OS_LINUX = getOsMatchesName("Linux") || getOsMatchesName("LINUX");
1216 
1217     /**
1218      * Is {@code true} if this is Mac.
1219      *
1220      * <p>
1221      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1222      * </p>
1223      * <p>
1224      * This value is initialized when the class is loaded.
1225      * </p>
1226      *
1227      * @since 2.0
1228      */
1229     public static final boolean IS_OS_MAC = getOsMatchesName("Mac");
1230 
1231     /**
1232      * Is {@code true} if this is Mac.
1233      *
1234      * <p>
1235      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1236      * </p>
1237      * <p>
1238      * This value is initialized when the class is loaded.
1239      * </p>
1240      *
1241      * @since 2.0
1242      */
1243     public static final boolean IS_OS_MAC_OSX = getOsMatchesName("Mac OS X");
1244 
1245     /**
1246      * Is {@code true} if this is macOS X Cheetah.
1247      *
1248      * <p>
1249      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1250      * </p>
1251      * <p>
1252      * This value is initialized when the class is loaded.
1253      * </p>
1254      *
1255      * @since 3.4
1256      */
1257     public static final boolean IS_OS_MAC_OSX_CHEETAH = getOsMatches("Mac OS X", "10.0");
1258 
1259     /**
1260      * Is {@code true} if this is macOS X Puma.
1261      *
1262      * <p>
1263      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1264      * </p>
1265      * <p>
1266      * This value is initialized when the class is loaded.
1267      * </p>
1268      *
1269      * @since 3.4
1270      */
1271     public static final boolean IS_OS_MAC_OSX_PUMA = getOsMatches("Mac OS X", "10.1");
1272 
1273     /**
1274      * Is {@code true} if this is macOS X Jaguar.
1275      *
1276      * <p>
1277      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1278      * </p>
1279      * <p>
1280      * This value is initialized when the class is loaded.
1281      * </p>
1282      *
1283      * @since 3.4
1284      */
1285     public static final boolean IS_OS_MAC_OSX_JAGUAR = getOsMatches("Mac OS X", "10.2");
1286 
1287     /**
1288      * Is {@code true} if this is macOS X Panther.
1289      *
1290      * <p>
1291      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1292      * </p>
1293      * <p>
1294      * This value is initialized when the class is loaded.
1295      * </p>
1296      *
1297      * @since 3.4
1298      */
1299     public static final boolean IS_OS_MAC_OSX_PANTHER = getOsMatches("Mac OS X", "10.3");
1300 
1301     /**
1302      * Is {@code true} if this is macOS X Tiger.
1303      *
1304      * <p>
1305      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1306      * </p>
1307      * <p>
1308      * This value is initialized when the class is loaded.
1309      * </p>
1310      *
1311      * @since 3.4
1312      */
1313     public static final boolean IS_OS_MAC_OSX_TIGER = getOsMatches("Mac OS X", "10.4");
1314 
1315     /**
1316      * Is {@code true} if this is macOS X Leopard.
1317      *
1318      * <p>
1319      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1320      * </p>
1321      * <p>
1322      * This value is initialized when the class is loaded.
1323      * </p>
1324      *
1325      * @since 3.4
1326      */
1327     public static final boolean IS_OS_MAC_OSX_LEOPARD = getOsMatches("Mac OS X", "10.5");
1328 
1329     /**
1330      * Is {@code true} if this is macOS X Snow Leopard.
1331      *
1332      * <p>
1333      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1334      * </p>
1335      * <p>
1336      * This value is initialized when the class is loaded.
1337      * </p>
1338      *
1339      * @since 3.4
1340      */
1341     public static final boolean IS_OS_MAC_OSX_SNOW_LEOPARD = getOsMatches("Mac OS X", "10.6");
1342 
1343     /**
1344      * Is {@code true} if this is macOS X Lion.
1345      *
1346      * <p>
1347      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1348      * </p>
1349      * <p>
1350      * This value is initialized when the class is loaded.
1351      * </p>
1352      *
1353      * @since 3.4
1354      */
1355     public static final boolean IS_OS_MAC_OSX_LION = getOsMatches("Mac OS X", "10.7");
1356 
1357     /**
1358      * Is {@code true} if this is macOS X Mountain Lion.
1359      *
1360      * <p>
1361      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1362      * </p>
1363      * <p>
1364      * This value is initialized when the class is loaded.
1365      * </p>
1366      *
1367      * @since 3.4
1368      */
1369     public static final boolean IS_OS_MAC_OSX_MOUNTAIN_LION = getOsMatches("Mac OS X", "10.8");
1370 
1371     /**
1372      * Is {@code true} if this is macOS X Mavericks.
1373      *
1374      * <p>
1375      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1376      * </p>
1377      * <p>
1378      * This value is initialized when the class is loaded.
1379      * </p>
1380      *
1381      * @since 3.4
1382      */
1383     public static final boolean IS_OS_MAC_OSX_MAVERICKS = getOsMatches("Mac OS X", "10.9");
1384 
1385     /**
1386      * Is {@code true} if this is macOS X Yosemite.
1387      *
1388      * <p>
1389      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1390      * </p>
1391      * <p>
1392      * This value is initialized when the class is loaded.
1393      * </p>
1394      *
1395      * @since 3.4
1396      */
1397     public static final boolean IS_OS_MAC_OSX_YOSEMITE = getOsMatches("Mac OS X", "10.10");
1398 
1399     /**
1400      * Is {@code true} if this is macOS X El Capitan.
1401      *
1402      * <p>
1403      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1404      * </p>
1405      * <p>
1406      * This value is initialized when the class is loaded.
1407      * </p>
1408      *
1409      * @since 3.5
1410      */
1411     public static final boolean IS_OS_MAC_OSX_EL_CAPITAN = getOsMatches("Mac OS X", "10.11");
1412 
1413     /**
1414      * Is {@code true} if this is macOS X Sierra.
1415      *
1416      * <p>
1417      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1418      * </p>
1419      * <p>
1420      * This value is initialized when the class is loaded.
1421      * </p>
1422      *
1423      * @since 3.12.0
1424      */
1425     public static final boolean IS_OS_MAC_OSX_SIERRA = getOsMatches("Mac OS X", "10.12");
1426 
1427     /**
1428      * Is {@code true} if this is macOS X High Sierra.
1429      *
1430      * <p>
1431      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1432      * </p>
1433      * <p>
1434      * This value is initialized when the class is loaded.
1435      * </p>
1436      *
1437      * @since 3.12.0
1438      */
1439     public static final boolean IS_OS_MAC_OSX_HIGH_SIERRA = getOsMatches("Mac OS X", "10.13");
1440 
1441     /**
1442      * Is {@code true} if this is macOS X Mojave.
1443      *
1444      * <p>
1445      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1446      * </p>
1447      * <p>
1448      * This value is initialized when the class is loaded.
1449      * </p>
1450      *
1451      * @since 3.12.0
1452      */
1453     public static final boolean IS_OS_MAC_OSX_MOJAVE = getOsMatches("Mac OS X", "10.14");
1454 
1455     /**
1456      * Is {@code true} if this is macOS X Catalina.
1457      *
1458      * <p>
1459      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1460      * </p>
1461      * <p>
1462      * This value is initialized when the class is loaded.
1463      * </p>
1464      *
1465      * @since 3.12.0
1466      */
1467     public static final boolean IS_OS_MAC_OSX_CATALINA = getOsMatches("Mac OS X", "10.15");
1468 
1469     /**
1470      * Is {@code true} if this is macOS X Big Sur.
1471      *
1472      * <p>
1473      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1474      * </p>
1475      * <p>
1476      * This value is initialized when the class is loaded.
1477      * </p>
1478      *
1479      * @since 3.12.0
1480      */
1481     public static final boolean IS_OS_MAC_OSX_BIG_SUR = getOsMatches("Mac OS X", "11");
1482 
1483     /**
1484      * Is {@code true} if this is macOS X Monterey.
1485      *
1486      * <p>
1487      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1488      * </p>
1489      * <p>
1490      * This value is initialized when the class is loaded.
1491      * </p>
1492      * @since 3.13.0
1493      */
1494     public static final boolean IS_OS_MAC_OSX_MONTEREY = getOsMatches("Mac OS X", "12");
1495 
1496     /**
1497      * Is {@code true} if this is macOS X Ventura.
1498      *
1499      * <p>
1500      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1501      * </p>
1502      * <p>
1503      * This value is initialized when the class is loaded.
1504      * </p>
1505      * @since 3.13.0
1506      */
1507     public static final boolean IS_OS_MAC_OSX_VENTURA = getOsMatches("Mac OS X", "13");
1508 
1509     /**
1510      * Is {@code true} if this is macOS X Sonoma.
1511      *
1512      * <p>
1513      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1514      * </p>
1515      * <p>
1516      * This value is initialized when the class is loaded.
1517      * </p>
1518      * @since 3.15.0
1519      */
1520     public static final boolean IS_OS_MAC_OSX_SONOMA = getOsMatches("Mac OS X", "14");
1521 
1522     /**
1523      * Is {@code true} if this is FreeBSD.
1524      *
1525      * <p>
1526      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1527      * </p>
1528      * <p>
1529      * This value is initialized when the class is loaded.
1530      * </p>
1531      *
1532      * @since 3.1
1533      */
1534     public static final boolean IS_OS_FREE_BSD = getOsMatchesName("FreeBSD");
1535 
1536     /**
1537      * Is {@code true} if this is OpenBSD.
1538      *
1539      * <p>
1540      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1541      * </p>
1542      * <p>
1543      * This value is initialized when the class is loaded.
1544      * </p>
1545      *
1546      * @since 3.1
1547      */
1548     public static final boolean IS_OS_OPEN_BSD = getOsMatchesName("OpenBSD");
1549 
1550     /**
1551      * Is {@code true} if this is NetBSD.
1552      *
1553      * <p>
1554      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1555      * </p>
1556      * <p>
1557      * This value is initialized when the class is loaded.
1558      * </p>
1559      *
1560      * @since 3.1
1561      */
1562     public static final boolean IS_OS_NET_BSD = getOsMatchesName("NetBSD");
1563 
1564     /**
1565      * Is {@code true} if this is OS/2.
1566      *
1567      * <p>
1568      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1569      * </p>
1570      * <p>
1571      * This value is initialized when the class is loaded.
1572      * </p>
1573      *
1574      * @since 2.0
1575      */
1576     public static final boolean IS_OS_OS2 = getOsMatchesName("OS/2");
1577 
1578     /**
1579      * Is {@code true} if this is Solaris.
1580      *
1581      * <p>
1582      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1583      * </p>
1584      * <p>
1585      * This value is initialized when the class is loaded.
1586      * </p>
1587      *
1588      * @since 2.0
1589      */
1590     public static final boolean IS_OS_SOLARIS = getOsMatchesName("Solaris");
1591 
1592     /**
1593      * Is {@code true} if this is SunOS.
1594      *
1595      * <p>
1596      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1597      * </p>
1598      * <p>
1599      * This value is initialized when the class is loaded.
1600      * </p>
1601      *
1602      * @since 2.0
1603      */
1604     public static final boolean IS_OS_SUN_OS = getOsMatchesName("SunOS");
1605 
1606     /**
1607      * Is {@code true} if this is a UNIX like system, as in any of AIX, HP-UX, Irix, Linux, MacOSX, Solaris or SUN OS.
1608      *
1609      * <p>
1610      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1611      * </p>
1612      * <p>
1613      * This value is initialized when the class is loaded.
1614      * </p>
1615      *
1616      * @since 2.1
1617      */
1618     public static final boolean IS_OS_UNIX = IS_OS_AIX || IS_OS_HP_UX || IS_OS_IRIX || IS_OS_LINUX || IS_OS_MAC_OSX
1619             || IS_OS_SOLARIS || IS_OS_SUN_OS || IS_OS_FREE_BSD || IS_OS_OPEN_BSD || IS_OS_NET_BSD;
1620 
1621     /**
1622      * Is {@code true} if this is Windows.
1623      *
1624      * <p>
1625      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1626      * </p>
1627      * <p>
1628      * This value is initialized when the class is loaded.
1629      * </p>
1630      *
1631      * @since 2.0
1632      */
1633     public static final boolean IS_OS_WINDOWS = getOsMatchesName(OS_NAME_WINDOWS_PREFIX);
1634 
1635     /**
1636      * Is {@code true} if this is Windows 2000.
1637      *
1638      * <p>
1639      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1640      * </p>
1641      * <p>
1642      * This value is initialized when the class is loaded.
1643      * </p>
1644      *
1645      * @since 2.0
1646      */
1647     public static final boolean IS_OS_WINDOWS_2000 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 2000");
1648 
1649     /**
1650      * Is {@code true} if this is Windows 2003.
1651      *
1652      * <p>
1653      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1654      * </p>
1655      * <p>
1656      * This value is initialized when the class is loaded.
1657      * </p>
1658      *
1659      * @since 3.1
1660      */
1661     public static final boolean IS_OS_WINDOWS_2003 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 2003");
1662 
1663     /**
1664      * Is {@code true} if this is Windows Server 2008.
1665      *
1666      * <p>
1667      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1668      * </p>
1669      * <p>
1670      * This value is initialized when the class is loaded.
1671      * </p>
1672      *
1673      * @since 3.1
1674      */
1675     public static final boolean IS_OS_WINDOWS_2008 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " Server 2008");
1676 
1677     /**
1678      * Is {@code true} if this is Windows Server 2012.
1679      *
1680      * <p>
1681      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1682      * </p>
1683      * <p>
1684      * This value is initialized when the class is loaded.
1685      * </p>
1686      *
1687      * @since 3.4
1688      */
1689     public static final boolean IS_OS_WINDOWS_2012 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " Server 2012");
1690 
1691     /**
1692      * Is {@code true} if this is Windows 95.
1693      *
1694      * <p>
1695      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1696      * </p>
1697      * <p>
1698      * This value is initialized when the class is loaded.
1699      * </p>
1700      *
1701      * @since 2.0
1702      */
1703     public static final boolean IS_OS_WINDOWS_95 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 95");
1704 
1705     /**
1706      * Is {@code true} if this is Windows 98.
1707      *
1708      * <p>
1709      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1710      * </p>
1711      * <p>
1712      * This value is initialized when the class is loaded.
1713      * </p>
1714      *
1715      * @since 2.0
1716      */
1717     public static final boolean IS_OS_WINDOWS_98 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 98");
1718 
1719     /**
1720      * Is {@code true} if this is Windows ME.
1721      *
1722      * <p>
1723      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1724      * </p>
1725      * <p>
1726      * This value is initialized when the class is loaded.
1727      * </p>
1728      *
1729      * @since 2.0
1730      */
1731     public static final boolean IS_OS_WINDOWS_ME = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " Me");
1732 
1733     /**
1734      * Is {@code true} if this is Windows NT.
1735      *
1736      * <p>
1737      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1738      * </p>
1739      * <p>
1740      * This value is initialized when the class is loaded.
1741      * </p>
1742      *
1743      * @since 2.0
1744      */
1745     public static final boolean IS_OS_WINDOWS_NT = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " NT");
1746 
1747     /**
1748      * Is {@code true} if this is Windows XP.
1749      *
1750      * <p>
1751      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1752      * </p>
1753      * <p>
1754      * This value is initialized when the class is loaded.
1755      * </p>
1756      *
1757      * @since 2.0
1758      */
1759     public static final boolean IS_OS_WINDOWS_XP = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " XP");
1760 
1761     /**
1762      * Is {@code true} if this is Windows Vista.
1763      *
1764      * <p>
1765      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1766      * </p>
1767      * <p>
1768      * This value is initialized when the class is loaded.
1769      * </p>
1770      *
1771      * @since 2.4
1772      */
1773     public static final boolean IS_OS_WINDOWS_VISTA = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " Vista");
1774 
1775     /**
1776      * Is {@code true} if this is Windows 7.
1777      *
1778      * <p>
1779      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1780      * </p>
1781      * <p>
1782      * This value is initialized when the class is loaded.
1783      * </p>
1784      *
1785      * @since 3.0
1786      */
1787     public static final boolean IS_OS_WINDOWS_7 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 7");
1788 
1789     /**
1790      * Is {@code true} if this is Windows 8.
1791      *
1792      * <p>
1793      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1794      * </p>
1795      * <p>
1796      * This value is initialized when the class is loaded.
1797      * </p>
1798      *
1799      * @since 3.2
1800      */
1801     public static final boolean IS_OS_WINDOWS_8 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 8");
1802 
1803     /**
1804      * Is {@code true} if this is Windows 10.
1805      *
1806      * <p>
1807      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1808      * </p>
1809      * <p>
1810      * This value is initialized when the class is loaded.
1811      * </p>
1812      *
1813      * @since 3.5
1814      */
1815     public static final boolean IS_OS_WINDOWS_10 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 10");
1816 
1817     /**
1818      * Is {@code true} if this is Windows 11.
1819      *
1820      * <p>
1821      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1822      * </p>
1823      * <p>
1824      * OpenJDK fixed the return value for {@code os.name} on Windows 11 to versions 8, 11, and 17:
1825      * </p>
1826      * <ul>
1827      * <li>Affects Java versions 7u321, 8u311, 11.0.13-oracle, 17.0.1: https://bugs.openjdk.org/browse/JDK-8274737</li>
1828      * <li>Fixed in OpenJDK commit https://github.com/openjdk/jdk/commit/97ea9dd2f24f9f1fb9b9345a4202a825ee28e014</li>
1829      * </ul>
1830      * <p>
1831      * This value is initialized when the class is loaded.
1832      * </p>
1833      *
1834      * @since 3.13.0
1835      */
1836     public static final boolean IS_OS_WINDOWS_11 = getOsMatchesName(OS_NAME_WINDOWS_PREFIX + " 11");
1837 
1838     /**
1839      * Is {@code true} if this is z/OS.
1840      *
1841      * <p>
1842      * The field will return {@code false} if {@code OS_NAME} is {@code null}.
1843      * </p>
1844      * <p>
1845      * This value is initialized when the class is loaded.
1846      * </p>
1847      *
1848      * @since 3.5
1849      */
1850     // Values on a z/OS system I tested (Gary Gregory - 2016-03-12)
1851     // os.arch = s390x
1852     // os.encoding = ISO8859_1
1853     // os.name = z/OS
1854     // os.version = 02.02.00
1855     public static final boolean IS_OS_ZOS = getOsMatchesName("z/OS");
1856 
1857     /**
1858      * The System property key for the user home directory.
1859      */
1860     public static final String USER_HOME_KEY = "user.home";
1861 
1862     /**
1863      * The System property key for the user name.
1864      *
1865      * @deprecated Use {@link SystemProperties#USER_NAME}.
1866      */
1867     @Deprecated
1868     public static final String USER_NAME_KEY = "user.name";
1869 
1870     /**
1871      * The System property key for the user directory.
1872      *
1873      * @deprecated Use {@link SystemProperties#USER_DIR}.
1874      */
1875     @Deprecated
1876     public static final String USER_DIR_KEY = "user.dir";
1877 
1878     /**
1879      * The System property key for the Java IO temporary directory.
1880      *
1881      * @deprecated Use {@link SystemProperties#JAVA_IO_TMPDIR}.
1882      */
1883     @Deprecated
1884     public static final String JAVA_IO_TMPDIR_KEY = "java.io.tmpdir";
1885 
1886     /**
1887      * The System property key for the Java home directory.
1888      *
1889      * @deprecated Use {@link SystemProperties#JAVA_HOME}.
1890      */
1891     @Deprecated
1892     public static final String JAVA_HOME_KEY = "java.home";
1893 
1894     /**
1895      * The {@code awt.toolkit} System Property.
1896      *
1897      * <p>
1898      * Holds a class name, on Windows XP this is {@code sun.awt.windows.WToolkit}.
1899      * </p>
1900      * <p>
1901      * <b>On platforms without a GUI, this value is {@code null}.</b>
1902      * </p>
1903      * <p>
1904      * Defaults to {@code null} if the runtime does not have security access to read this property or the property does
1905      * not exist.
1906      * </p>
1907      * <p>
1908      * This value is initialized when the class is loaded. If {@link System#setProperty(String,String)} or
1909      * {@link System#setProperties(java.util.Properties)} is called after this class is loaded, the value will be out of
1910      * sync with that System property.
1911      * </p>
1912      *
1913      * @since 2.1
1914      * @see SystemProperties#getAwtToolkit()
1915      */
1916     public static final String AWT_TOOLKIT = SystemProperties.getAwtToolkit();
1917 
1918     /**
1919      * Gets an environment variable, defaulting to {@code defaultValue} if the variable cannot be read.
1920      *
1921      * <p>
1922      * If a {@link SecurityException} is caught, the return value is {@code defaultValue} and a message is written to
1923      * {@code System.err}.
1924      * </p>
1925      *
1926      * @param name
1927      *            the environment variable name
1928      * @param defaultValue
1929      *            the default value
1930      * @return the environment variable value or {@code defaultValue} if a security problem occurs
1931      * @since 3.8
1932      */
1933     public static String getEnvironmentVariable(final String name, final String defaultValue) {
1934         try {
1935             final String value = System.getenv(name);
1936             return value == null ? defaultValue : value;
1937         } catch (final SecurityException ex) {
1938             // we are not allowed to look at this property
1939             // System.err.println("Caught a SecurityException reading the environment variable '" + name + "'.");
1940             return defaultValue;
1941         }
1942     }
1943 
1944     /**
1945      * Gets the host name from an environment variable
1946      * (COMPUTERNAME on Windows, HOSTNAME elsewhere).
1947      *
1948      * <p>
1949      * If you want to know what the network stack says is the host name, you should use {@code InetAddress.getLocalHost().getHostName()}.
1950      * </p>
1951      *
1952      * @return the host name. Will be {@code null} if the environment variable is not defined.
1953      * @since 3.6
1954      */
1955     public static String getHostName() {
1956         return IS_OS_WINDOWS ? System.getenv("COMPUTERNAME") : System.getenv("HOSTNAME");
1957     }
1958 
1959     /**
1960      * Gets the current Java home directory as a {@link File}.
1961      *
1962      * @return a directory
1963      * @throws SecurityException if a security manager exists and its {@code checkPropertyAccess} method doesn't allow
1964      * access to the specified system property.
1965      * @see SystemProperties#getJavaHome()
1966      * @since 2.1
1967      */
1968     public static File getJavaHome() {
1969         return new File(SystemProperties.getJavaHome());
1970     }
1971 
1972     /**
1973      * Gets the current Java IO temporary directory as a {@link File}.
1974      *
1975      * @return a directory
1976      * @throws SecurityException if a security manager exists and its {@code checkPropertyAccess} method doesn't allow
1977      * access to the specified system property.
1978      * @see SystemProperties#getJavaIoTmpdir()
1979      * @since 2.1
1980      */
1981     public static File getJavaIoTmpDir() {
1982         return new File(SystemProperties.getJavaIoTmpdir());
1983     }
1984 
1985     /**
1986      * Decides if the Java version matches.
1987      *
1988      * @param versionPrefix the prefix for the Java version
1989      * @return true if matches, or false if not or can't determine
1990      */
1991     private static boolean getJavaVersionMatches(final String versionPrefix) {
1992         return isJavaVersionMatch(JAVA_SPECIFICATION_VERSION, versionPrefix);
1993     }
1994 
1995     /**
1996      * Decides if the operating system matches.
1997      *
1998      * @param osNamePrefix the prefix for the OS name
1999      * @param osVersionPrefix the prefix for the version
2000      * @return true if matches, or false if not or can't determine
2001      */
2002     private static boolean getOsMatches(final String osNamePrefix, final String osVersionPrefix) {
2003         return isOsMatch(OS_NAME, OS_VERSION, osNamePrefix, osVersionPrefix);
2004     }
2005 
2006     /**
2007      * Decides if the operating system matches.
2008      *
2009      * @param osNamePrefix the prefix for the OS name
2010      * @return true if matches, or false if not or can't determine
2011      */
2012     private static boolean getOsMatchesName(final String osNamePrefix) {
2013         return isOsNameMatch(OS_NAME, osNamePrefix);
2014     }
2015 
2016     /**
2017      * Gets the current user directory as a {@link File}.
2018      *
2019      * @return a directory
2020      * @throws SecurityException if a security manager exists and its {@code checkPropertyAccess} method doesn't allow
2021      * access to the specified system property.
2022      * @see SystemProperties#getUserDir()
2023      * @since 2.1
2024      */
2025     public static File getUserDir() {
2026         return new File(SystemProperties.getUserDir());
2027     }
2028 
2029     /**
2030      * Gets the current user home directory as a {@link File}.
2031      *
2032      * @return a directory
2033      * @throws SecurityException if a security manager exists and its {@code checkPropertyAccess} method doesn't allow
2034      * access to the specified system property.
2035      * @see SystemProperties#getUserHome()
2036      * @since 2.1
2037      */
2038     public static File getUserHome() {
2039         return new File(SystemProperties.getUserHome());
2040     }
2041 
2042     /**
2043      * Gets the current user name.
2044      *
2045      * @return a name
2046      * @throws SecurityException if a security manager exists and its {@code checkPropertyAccess} method doesn't allow
2047      * access to the specified system property.
2048      * @see SystemProperties#getUserName()
2049      * @since 3.10
2050      * @deprecated Use {@link SystemProperties#getUserName()}.
2051      */
2052     @Deprecated
2053     public static String getUserName() {
2054         return SystemProperties.getUserName();
2055     }
2056 
2057     /**
2058      * Gets the user name.
2059      *
2060      * @param defaultValue A default value.
2061      * @return a name
2062      * @throws SecurityException if a security manager exists and its {@code checkPropertyAccess} method doesn't allow
2063      * access to the specified system property.
2064      * @see SystemProperties#getUserName()
2065      * @since 3.10
2066      * @deprecated Use {@link SystemProperties#getUserName(String)}.
2067      */
2068     @Deprecated
2069     public static String getUserName(final String defaultValue) {
2070         return SystemProperties.getUserName(defaultValue);
2071     }
2072 
2073     /**
2074      * Returns whether the {@link #JAVA_AWT_HEADLESS} value is {@code true}.
2075      *
2076      * @return {@code true} if {@code JAVA_AWT_HEADLESS} is {@code "true"}, {@code false} otherwise.
2077      * @see #JAVA_AWT_HEADLESS
2078      * @since 2.1
2079      * @since Java 1.4
2080      */
2081     public static boolean isJavaAwtHeadless() {
2082         return Boolean.TRUE.toString().equals(JAVA_AWT_HEADLESS);
2083     }
2084 
2085     /**
2086      * Is the Java version at least the requested version.
2087      *
2088      * @param requiredVersion the required version, for example 1.31f
2089      * @return {@code true} if the actual version is equal or greater than the required version
2090      */
2091     public static boolean isJavaVersionAtLeast(final JavaVersion requiredVersion) {
2092         return JAVA_SPECIFICATION_VERSION_AS_ENUM.atLeast(requiredVersion);
2093     }
2094 
2095     /**
2096      * Is the Java version at most the requested version.
2097      *
2098      * <p>
2099      * Example input:
2100      * </p>
2101      *
2102      * @param requiredVersion the required version, for example 1.31f
2103      * @return {@code true} if the actual version is equal or less than the required version
2104      * @since 3.9
2105      */
2106     public static boolean isJavaVersionAtMost(final JavaVersion requiredVersion) {
2107         return JAVA_SPECIFICATION_VERSION_AS_ENUM.atMost(requiredVersion);
2108     }
2109 
2110     /**
2111      * Decides if the Java version matches.
2112      *
2113      * <p>
2114      * This method is package private instead of private to support unit test invocation.
2115      * </p>
2116      *
2117      * @param version the actual Java version
2118      * @param versionPrefix the prefix for the expected Java version
2119      * @return true if matches, or false if not or can't determine
2120      */
2121     static boolean isJavaVersionMatch(final String version, final String versionPrefix) {
2122         if (version == null) {
2123             return false;
2124         }
2125         return version.startsWith(versionPrefix);
2126     }
2127 
2128     /**
2129      * Decides if the operating system matches.
2130      * <p>
2131      * This method is package private instead of private to support unit test invocation.
2132      * </p>
2133      *
2134      * @param osName the actual OS name
2135      * @param osVersion the actual OS version
2136      * @param osNamePrefix the prefix for the expected OS name
2137      * @param osVersionPrefix the prefix for the expected OS version
2138      * @return true if matches, or false if not or can't determine
2139      */
2140     static boolean isOsMatch(final String osName, final String osVersion, final String osNamePrefix, final String osVersionPrefix) {
2141         if (osName == null || osVersion == null) {
2142             return false;
2143         }
2144         return isOsNameMatch(osName, osNamePrefix) && isOsVersionMatch(osVersion, osVersionPrefix);
2145     }
2146 
2147     /**
2148      * Decides if the operating system matches.
2149      * <p>
2150      * This method is package private instead of private to support unit test invocation.
2151      * </p>
2152      *
2153      * @param osName the actual OS name
2154      * @param osNamePrefix the prefix for the expected OS name
2155      * @return true if matches, or false if not or can't determine
2156      */
2157     static boolean isOsNameMatch(final String osName, final String osNamePrefix) {
2158         if (osName == null) {
2159             return false;
2160         }
2161         return osName.startsWith(osNamePrefix);
2162     }
2163 
2164     /**
2165      * Decides if the operating system version matches.
2166      * <p>
2167      * This method is package private instead of private to support unit test invocation.
2168      * </p>
2169      *
2170      * @param osVersion the actual OS version
2171      * @param osVersionPrefix the prefix for the expected OS version
2172      * @return true if matches, or false if not or can't determine
2173      */
2174     static boolean isOsVersionMatch(final String osVersion, final String osVersionPrefix) {
2175         if (StringUtils.isEmpty(osVersion)) {
2176             return false;
2177         }
2178         // Compare parts of the version string instead of using String.startsWith(String) because otherwise
2179         // osVersionPrefix 10.1 would also match osVersion 10.10
2180         final String[] versionPrefixParts = JavaVersion.split(osVersionPrefix);
2181         final String[] versionParts = JavaVersion.split(osVersion);
2182         for (int i = 0; i < Math.min(versionPrefixParts.length, versionParts.length); i++) {
2183             if (!versionPrefixParts[i].equals(versionParts[i])) {
2184                 return false;
2185             }
2186         }
2187         return true;
2188     }
2189 
2190     /**
2191      * SystemUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
2192      * {@code SystemUtils.FILE_SEPARATOR}.
2193      *
2194      * <p>
2195      * This constructor is public to permit tools that require a JavaBean instance to operate.
2196      * </p>
2197      */
2198     public SystemUtils() {
2199     }
2200 
2201 }