1 /*
2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk;
27
28 import java.math.BigInteger;
29 import java.security.AccessController;
30 import java.security.PrivilegedAction;
31 import java.util.regex.Matcher;
32 import java.util.regex.Pattern;
33 import java.util.stream.Collectors;
34 import java.util.Arrays;
35 import java.util.Collections;
36 import java.util.List;
37 import java.util.Optional;
38
39 /**
40 * A representation of the JDK version-string which contains a version
41 * number optionally followed by pre-release and build information.
42 *
43 * <h2><a name="verNum">Version numbers</a></h2>
44 *
45 * A <em>version number</em>, {@code $VNUM}, is a non-empty sequence of
46 * non-negative integer numerals, without leading or trailing zeroes,
47 * separated by period characters (U+002E); i.e., it matches the regular
48 * expression {@code ^[1-9][0-9]*(((\.0)*\.[1-9][0-9]*)*)*$}. The sequence may
49 * be of arbitrary length but the first three elements are assigned specific
50 * meanings, as follows:
51 *
52 * <blockquote><pre>
53 * $MAJOR.$MINOR.$SECURITY
54 * </pre></blockquote>
55 *
56 * <ul>
57 *
58 * <li><p> <a name="major">{@code $MAJOR}</a> --- The major version number,
59 * incremented for a major release that contains significant new features as
60 * specified in a new edition of the Java SE Platform Specification,
61 * <em>e.g.</em>, <a href="https://jcp.org/en/jsr/detail?id=337">JSR 337</a>
62 * for Java SE 8. Features may be removed in a major release, given
63 * advance notice at least one major release ahead of time, and incompatible
64 * changes may be made when justified. The {@code $MAJOR} version number of
65 * JDK 8 was {@code 8}; the {@code $MAJOR} version number of JDK 9
66 * is {@code 9}. </p></li>
67 *
68 * <li><p> <a name="minor">{@code $MINOR}</a> --- The minor version number,
69 * incremented for a minor update release that may contain compatible bug
70 * fixes, revisions to standard APIs mandated by a <a
71 * href="https://jcp.org/en/procedures/jcp2#5.3">Maintenance Release</a> of
72 * the relevant Platform Specification, and implementation features outside
73 * the scope of that Specification such as new JDK-specific APIs, additional
74 * service providers, new garbage collectors, and ports to new hardware
75 * architectures. {@code $MINOR} is reset to zero when {@code $MAJOR} is
76 * incremented. </p></li>
77 *
78 * <li><p> <a name="security">{@code $SECURITY}</a> --- The security level,
79 * incremented for a security-update release that contains critical fixes
80 * including those necessary to improve security. {@code $SECURITY} is reset
81 * to zero <strong>only</strong> when {@code $MAJOR} is incremented. A higher
82 * value of {@code $SECURITY} for a given {@code $MAJOR} value, therefore,
83 * always indicates a more secure release, regardless of the value of {@code
84 * $MINOR}. </p></li>
85 *
86 * </ul>
87 *
88 * <p> The fourth and later elements of a version number are free for use by
89 * downstream consumers of the JDK code base. Such a consumer may,
90 * <em>e.g.</em>, use the fourth element to identify patch releases which
91 * contain a small number of critical non-security fixes in addition to the
92 * security fixes in the corresponding security release. </p>
93 *
94 * <p> The version number does not include trailing zero elements;
95 * <em>i.e.</em>, {@code $SECURITY} is omitted if it has the value zero, and
96 * {@code $MINOR} is omitted if both {@code $MINOR} and {@code $SECURITY} have
97 * the value zero. </p>
98 *
99 * <p> The sequence of numerals in a version number is compared to another
100 * such sequence in numerical, pointwise fashion; <em>e.g.</em>, {@code 9.9.1}
101 * is less than {@code 9.10.0}. If one sequence is shorter than another then
102 * the missing elements of the shorter sequence are considered to be zero;
103 * <em>e.g.</em>, {@code 9.1.2} is equal to {@code 9.1.2.0} but less than
104 * {@code 9.1.2.1}. </p>
105 *
106 * <h2><a name="verStr">Version strings</a></h2>
107 *
108 * <p> A <em>version string</em> {@code $VSTR} consists of a version number
109 * {@code $VNUM}, as described above, optionally followed by pre-release and
110 * build information, in the format </p>
111 *
112 * <blockquote><pre>
113 * $VNUM(-$PRE)?(\+($BUILD)?(-$OPT)?)?
114 * </pre></blockquote>
115 *
116 * <p> where: </p>
117 *
118 * <ul>
119 *
120 * <li><p> <a name="pre">{@code $PRE}</a>, matching {@code ([a-zA-Z0-9]+)} ---
121 * A pre-release identifier. Typically {@code ea}, for an early-access
122 * release that's under active development and potentially unstable, or {@code
123 * internal}, for an internal developer build.
124 *
125 * <li><p> <a name="build">{@code $BUILD}</a>, matching {@code
126 * (0|[1-9][0-9]*)} --- The build number, incremented for each promoted build.
127 * {@code $BUILD} is reset to {@code 1} when any portion of {@code $VNUM} is
128 * incremented. </p>
129 *
130 * <li><p> <a name="opt">{@code $OPT}</a>, matching {@code ([-a-zA-Z0-9\.]+)}
131 * --- Additional build information, if desired. In the case of an {@code
132 * internal} build this will often contain the date and time of the
133 * build. </p>
134 *
135 * </ul>
136 *
137 * <p> When comparing two version strings the value of {@code $OPT}, if
138 * present, may or may not be significant depending on the chosen comparison
139 * method. The comparison methods {@link #compareTo(Version) compareTo()} and
140 * {@link #compareToIgnoreOpt(Version) compareToIgnoreOpt{}} should be used
141 * consistently with the corresponding methods {@link #equals(Object) equals()}
142 * and {@link #equalsIgnoreOpt(Object) equalsIgnoreOpt()}. </p>
143 *
144 * <p> A <em>short version string</em> ({@code $SVSTR}), often useful in less
145 * formal contexts, is simply {@code $VNUM} optionally ended with {@code
146 * -$PRE}. </p>
147 *
148 * @since 9
149 */
150 public final class Version
151 implements Comparable<Version>
152 {
153 private final List<Integer> version;
154 private final Optional<String> pre;
155 private final Optional<Integer> build;
156 private final Optional<String> optional;
157
158 private static Version current;
159
160 // $VNUM(-$PRE)?(\+($BUILD)?(\-$OPT)?)?
161 // RE accepts only compliant version strings
162 // ([1-9][0-9]*(?:(?:\.0)*\.[1-9][0-9]*)*)(?:-([a-zA-Z0-9]+))?(?:(\+)(0|[1-9][0-9]*)?)?(?:-([-a-zA-Z0-9.]+))?
163
164 private static final String VNUM
165 = "(?<VNUM>[1-9][0-9]*(?:(?:\\.0)*\\.[1-9][0-9]*)*)";
166 private static final String VNUM_GROUP = "VNUM";
167
168 private static final String PRE = "(:?-(?<PRE>[a-zA-Z0-9]+))?";
169 private static final String PRE_GROUP = "PRE";
170
171 private static final String BUILD = "(?:(?<PLUS>\\+)(?<BUILD>0|[1-9][0-9]*)?)?";
172 private static final String PLUS_GROUP = "PLUS";
173 private static final String BUILD_GROUP = "BUILD";
174
175 private static final String OPT = "(?:-(?<OPT>[-a-zA-Z0-9.]+))?";
176 private static final String OPT_GROUP = "OPT";
177
178 private static final String VSTR_FORMAT
179 = "^" + VNUM + PRE + BUILD + OPT + "$";
180 private static final Pattern VSTR_PATTERN = Pattern.compile(VSTR_FORMAT);
181
182 /**
183 * Constructs a valid JDK <a href="verStr">version string</a> containing a
184 * <a href="#verNum">version number</a> followed by pre-release and build
185 * information.
186 *
187 * @param s
188 * A string to be interpreted as a version
189 *
190 * @throws IllegalArgumentException
191 * If the given string cannot be interpreted a valid version
192 *
193 * @throws NullPointerException
194 * If {@code s} is {@code null}
195 *
196 * @throws NumberFormatException
197 * If an element of the version number or the build number cannot
198 * be represented as an {@link Integer}
199 */
200 private Version(String s) {
201 if (s == null)
202 throw new NullPointerException();
203
204 Matcher m = VSTR_PATTERN.matcher(s);
205 if (!m.matches())
206 throw new IllegalArgumentException("Invalid version string: '"
207 + s + "'");
208
209 // $VNUM is a dot-separated list of integers of arbitrary length
210 version
211 = Collections.unmodifiableList(
212 Arrays.stream(m.group(VNUM_GROUP).split("\\."))
213 .map(Integer::parseInt)
214 .collect(Collectors.toList()));
215
216 pre = Optional.ofNullable(m.group(PRE_GROUP));
217
218 String b = m.group(BUILD_GROUP);
219 // $BUILD is an integer
220 build = (b == null)
221 ? Optional.<Integer>empty()
222 : Optional.ofNullable(Integer.parseInt(b));
223
224 optional = Optional.ofNullable(m.group(OPT_GROUP));
225
226 if ((m.group(PLUS_GROUP) != null)
227 && !build.isPresent() && !optional.isPresent()) {
228 throw new IllegalArgumentException("'+' found with neither build"
229 + " or optional components: '"
230 + s + "'");
231 }
232 }
233
234 /**
235 * Parses the given string as a valid JDK <a
236 * href="#verStr">version string</a> containing a <a
237 * href="#verNum">version number</a> followed by pre-release and
238 * build information.
239 *
240 * @param s
241 * A string to interpret as a version
242 *
243 * @throws IllegalArgumentException
244 * If the given string cannot be interpreted a valid version
245 *
246 * @throws NullPointerException
247 * If the given string is {@code null}
248 *
249 * @throws NumberFormatException
250 * If an element of the version number or the build number cannot
251 * be represented as an {@link Integer}
252 *
253 * @return This version
254 */
255 public static Version parse(String s) {
256 return new Version(s);
257 }
258
259 /**
260 * Returns {@code System.getProperty("java.version")} as a Version.
261 *
262 * @throws SecurityException
263 * If a security manager exists and its {@link
264 * SecurityManager#checkPropertyAccess(String)
265 * checkPropertyAccess} method does not allow access to the
266 * system property "java.version"
267 *
268 * @return {@code System.getProperty("java.version")} as a Version
269 */
270 public static Version current() {
271 if (current == null) {
272 current = parse(AccessController.doPrivileged(
273 new PrivilegedAction<>() {
274 public String run() {
275 return System.getProperty("java.version");
276 }
277 }));
278 }
279 return current;
280 }
281
282 /**
283 * Returns the <a href="#major">major</a> version number.
284 *
285 * @return The major version number
286 */
287 public int major() {
288 return version.get(0);
289 }
290
291 /**
292 * Returns the <a href="#minor">minor</a> version number or zero if it was
293 * not set.
294 *
295 * @return The minor version number or zero if it was not set
296 */
297 public int minor() {
298 return (version.size() > 1 ? version.get(1) : 0);
299 }
300
301 /**
302 * Returns the <a href="#security">security</a> version number or zero if
303 * it was not set.
304 *
305 * @return The security version number or zero if it was not set
306 */
307 public int security() {
308 return (version.size() > 2 ? version.get(2) : 0);
309 }
310
311 /**
312 * Returns an unmodifiable {@link java.util.List List} of the
313 * integer numerals contained in the <a href="#verNum">version
314 * number</a>. The {@code List} always contains at least one
315 * element corresponding to the <a href="#major">major version
316 * number</a>.
317 *
318 * @return An unmodifiable list of the integer numerals
319 * contained in the version number
320 */
321 public List<Integer> version() {
322 return version;
323 }
324
325 /**
326 * Returns the optional <a href="#pre">pre-release</a> information.
327 *
328 * @return The optional pre-release information as a String
329 */
330 public Optional<String> pre() {
331 return pre;
332 }
333
334 /**
335 * Returns the <a href="#build">build number</a>.
336 *
337 * @return The optional build number.
338 */
339 public Optional<Integer> build() {
340 return build;
341 }
342
343 /**
344 * Returns <a href="#opt">optional</a> additional identifying build
345 * information.
346 *
347 * @return Additional build information as a String
348 */
349 public Optional<String> optional() {
350 return optional;
351 }
352
353 /**
354 * Compares this version to another.
355 *
356 * <p> Each of the components in the <a href="#verStr">version</a> is
357 * compared in the follow order of precedence: version numbers,
358 * pre-release identifiers, build numbers, optional build information. </p>
359 *
360 * <p> Comparison begins by examining the sequence of version numbers. If
361 * one sequence is shorter than another, then the missing elements of the
362 * shorter sequence are considered to be zero. </p>
363 *
364 * <p> A version with a pre-release identifier is always considered to be
365 * less than a version without one. Pre-release identifiers are compared
366 * numerically when they consist only of digits, and lexicographically
367 * otherwise. Numeric identifiers are considered to be less than
368 * non-numeric identifiers. </p>
369 *
370 * <p> A version without a build number is always less than one with a
371 * build number; otherwise build numbers are compared numerically. </p>
372 *
373 * <p> The optional build information is compared lexicographically.
374 * During this comparison, a version with optional build information is
375 * considered to be greater than a version without one. </p>
376 *
377 * <p> A version is not comparable to any other type of object.
378 *
379 * @param ob
380 * The object to be compared
381 *
382 * @return A negative integer, zero, or a positive integer if this
383 * {@code Version} is less than, equal to, or greater than the
384 * given {@code Version}
385 *
386 * @throws NullPointerException
387 * If the given object is {@code null}
388 */
389 @Override
390 public int compareTo(Version ob) {
391 return compare(ob, false);
392 }
393
394 /**
395 * Compares this version to another disregarding optional build
396 * information.
397 *
398 * <p> Two versions are compared by examining the version string as
399 * described in {@link #compareTo(Version)} with the exception that the
400 * optional build information is always ignored. </p>
401 *
402 * <p> A version is not comparable to any other type of object.
403 *
404 * @param ob
405 * The object to be compared
406 *
407 * @return A negative integer, zero, or a positive integer if this
408 * {@code Version} is less than, equal to, or greater than the
409 * given {@code Version}
410 *
411 * @throws NullPointerException
412 * If the given object is {@code null}
413 */
414 public int compareToIgnoreOpt(Version ob) {
415 return compare(ob, true);
416 }
417
418 private int compare(Version ob, boolean ignoreOpt) {
419 if (ob == null)
420 throw new NullPointerException("Invalid argument");
421
422 int ret = compareVersion(ob);
423 if (ret != 0)
424 return ret;
425
426 ret = comparePre(ob);
427 if (ret != 0)
428 return ret;
429
430 ret = compareBuild(ob);
431 if (ret != 0)
432 return ret;
433
434 if (!ignoreOpt)
435 return compareOpt(ob);
436
437 return 0;
438 }
439
440 private int compareVersion(Version ob) {
441 int size = version.size();
442 int oSize = ob.version().size();
443 int min = Math.min(size, oSize);
444 for (int i = 0; i < min; i++) {
445 Integer val = version.get(i);
446 Integer oVal = ob.version().get(i);
447 if (val != oVal)
448 return val - oVal;
449 }
450 if (size != oSize)
451 return size - oSize;
452 return 0;
453 }
454
455 private int comparePre(Version ob) {
456 Optional<String> oPre = ob.pre();
457 if (!pre.isPresent()) {
458 if (oPre.isPresent())
459 return 1;
460 } else {
461 if (!oPre.isPresent())
462 return -1;
463 String val = pre.get();
464 String oVal = oPre.get();
465 if (val.matches("\\d+")) {
466 return (oVal.matches("\\d+")
467 ? (new BigInteger(val)).compareTo(new BigInteger(oVal))
468 : -1);
469 } else {
470 return (oVal.matches("\\d+")
471 ? 1
472 : val.compareTo(oVal));
473 }
474 }
475 return 0;
476 }
477
478 private int compareBuild(Version ob) {
479 Optional<Integer> oBuild = ob.build();
480 if (oBuild.isPresent()) {
481 return (build.isPresent()
482 ? build.get().compareTo(oBuild.get())
483 : 1);
484 } else if (build.isPresent()) {
485 return -1;
486 }
487 return 0;
488 }
489
490 private int compareOpt(Version ob) {
491 Optional<String> oOpt = ob.optional();
492 if (!optional.isPresent()) {
493 if (oOpt.isPresent())
494 return -1;
495 } else {
496 if (!oOpt.isPresent())
497 return 1;
498 return optional.get().compareTo(oOpt.get());
499 }
500 return 0;
501 }
502
503 /**
504 * Returns a string representation of this version.
505 *
506 * @return The version string
507 */
508 @Override
509 public String toString() {
510 StringBuilder sb
511 = new StringBuilder(version.stream()
512 .map(Object::toString)
513 .collect(Collectors.joining(".")));
514 pre.ifPresent(v -> sb.append("-").append(v));
515
516 if (build.isPresent()) {
517 sb.append("+").append(build.get());
518 if (optional.isPresent())
519 sb.append("-").append(optional.get());
520 } else {
521 if (optional.isPresent())
522 sb.append("+-").append(optional.get());
523 }
524
525 return sb.toString();
526 }
527
528 /**
529 * Determines whether this {@code Version} is equal to another object.
530 *
531 * <p> Two {@code Version}s are equal if and only if they represent the
532 * same version string.
533 *
534 * <p> This method satisfies the general contract of the {@link
535 * Object#equals(Object) Object.equals} method. </p>
536 *
537 * @param ob
538 * The object to which this {@code Version} is to be compared
539 *
540 * @return {@code true} if, and only if, the given object is a {@code
541 * Version} that is identical to this {@code Version}
542 *
543 */
544 @Override
545 public boolean equals(Object ob) {
546 boolean ret = equalsIgnoreOpt(ob);
547 if (!ret)
548 return false;
549
550 Version that = (Version)ob;
551 return (this.optional().equals(that.optional()));
552 }
553
554 /**
555 * Determines whether this {@code Version} is equal to another
556 * disregarding optional build information.
557 *
558 * <p> Two {@code Version}s are equal if and only if they represent the
559 * same version string disregarding the optional build information.
560 *
561 * @param ob
562 * The object to which this {@code Version} is to be compared
563 *
564 * @return {@code true} if, and only if, the given object is a {@code
565 * Version} that is identical to this {@code Version}
566 * ignoring the optinal build information
567 *
568 */
569 public boolean equalsIgnoreOpt(Object ob) {
570 if (this == ob)
571 return true;
572 if (!(ob instanceof Version))
573 return false;
574
575 Version that = (Version)ob;
576 return (this.version().equals(that.version())
577 && this.pre().equals(that.pre())
578 && this.build().equals(that.build()));
579 }
580
581 /**
582 * Returns the hash code of this version.
583 *
584 * <p> This method satisfies the general contract of the {@link
585 * Object#hashCode Object.hashCode} method.
586 *
587 * @return The hashcode of this version
588 */
589 @Override
590 public int hashCode() {
591 int h = 1;
592 int p = 17;
593
594 h = p * h + version.hashCode();
595 h = p * h + pre.hashCode();
596 h = p * h + build.hashCode();
597 h = p * h + optional.hashCode();
598
599 return h;
600 }
601 }