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.util.regex.Matcher;
30 import java.util.regex.Pattern;
31 import java.util.stream.Collectors;
32 import java.util.Arrays;
33 import java.util.Collections;
34 import java.util.List;
35 import java.util.Optional;
36
37 /**
38 * A representation of the JDK version-string which contains a version
39 * number optionally followed by pre-release and build information.
40 *
41 * <h2><a name="verNum">Version numbers</a></h2>
42 *
43 * A <em>version number</em>, {@code $VNUM}, is a non-empty sequence of
44 * non-negative integer numerals, without leading or trailing zeroes,
45 * separated by period characters (U+002E); i.e., it matches the regular
46 * expression {@code ^[1-9][0-9]*(((\.0)*\.[1-9][0-9]*)*)*$}. The sequence may
47 * be of arbitrary length but the first three elements are assigned specific
48 * meanings, as follows:
49 *
50 * <blockquote><pre>
51 * $MAJOR.$MINOR.$SECURITY
52 * </pre></blockquote>
53 *
54 * <ul>
55 *
56 * <li><p> <a name="major">{@code $MAJOR}</a> --- The major version number,
57 * incremented for a major release that contains significant new features as
58 * specified in a new edition of the Java SE Platform Specification,
59 * <em>e.g.</em>, <a href="https://jcp.org/en/jsr/detail?id=337">JSR 337</a>
60 * for Java SE 8. Features may be removed in a major release, given
61 * advance notice at least one major release ahead of time, and incompatible
62 * changes may be made when justified. The {@code $MAJOR} version number of
63 * JDK 8 was {@code 8}; the {@code $MAJOR} version number of JDK 9
64 * is {@code 9}. </p></li>
65 *
66 * <li><p> <a name="minor">{@code $MINOR}</a> --- The minor version number,
67 * incremented for a minor update release that may contain compatible bug
68 * fixes, revisions to standard APIs mandated by a <a
69 * href="https://jcp.org/en/procedures/jcp2#5.3">Maintenance Release</a> of
70 * the relevant Platform Specification, and implementation features outside
71 * the scope of that Specification such as new JDK-specific APIs, additional
72 * service providers, new garbage collectors, and ports to new hardware
73 * architectures. {@code $MINOR} is reset to zero when {@code $MAJOR} is
74 * incremented. </p></li>
75 *
76 * <li><p> <a name="security">{@code $SECURITY}</a> --- The security level,
77 * incremented for a security-update release that contains critical fixes
78 * including those necessary to improve security. {@code $SECURITY} is reset
79 * to zero <strong>only</strong> when {@code $MAJOR} is incremented. A higher
80 * value of {@code $SECURITY} for a given {@code $MAJOR} value, therefore,
81 * always indicates a more secure release, regardless of the value of {@code
82 * $MINOR}. </p></li>
83 *
84 * </ul>
85 *
86 * <p> The fourth and later elements of a version number are free for use by
87 * downstream consumers of the JDK code base. Such a consumer may,
88 * <em>e.g.</em>, use the fourth element to identify patch releases which
89 * contain a small number of critical non-security fixes in addition to the
90 * security fixes in the corresponding security release. </p>
91 *
92 * <p> The version number does not include trailing zero elements;
93 * <em>i.e.</em>, {@code $SECURITY} is omitted if it has the value zero, and
94 * {@code $MINOR} is omitted if both {@code $MINOR} and {@code $SECURITY} have
95 * the value zero. </p>
96 *
97 * <p> The sequence of numerals in a version number is compared to another
98 * such sequence in numerical, pointwise fashion; <em>e.g.</em>, {@code 9.9.1}
99 * is less than {@code 9.10.0}. If one sequence is shorter than another then
100 * the missing elements of the shorter sequence are considered to be zero;
101 * <em>e.g.</em>, {@code 9.1.2} is equal to {@code 9.1.2.0} but less than
102 * {@code 9.1.2.1}. </p>
103 *
104 * <h2><a name="verStr">Version strings</a></h2>
105 *
106 * <p> A <em>version string</em> {@code $VSTR} consists of a version number
107 * {@code $VNUM}, as described above, optionally followed by pre-release and
108 * build information, in the format </p>
109 *
110 * <blockquote><pre>
111 * $VNUM(-$PRE)?(\+$BUILD)?(-$OPT)?
112 * </pre></blockquote>
113 *
114 * <p> where: </p>
115 *
116 * <ul>
117 *
118 * <li><p> <a name="pre">{@code $PRE}</a>, matching {@code ([a-zA-Z0-9]+)} ---
119 * A pre-release identifier. Typically {@code ea}, for an early-access
120 * release that's under active development and potentially unstable, or {@code
121 * internal}, for an internal developer build.
122 *
123 * <p> When comparing two version strings, a string with a pre-release
124 * identifier is always less than one with an equal {@code $VNUM} but no such
125 * identifier. Pre-release identifiers are compared numerically when they
126 * consist only of digits, and lexicographically otherwise. Numeric
127 * identifiers are less than than non-numeric identifiers. </p></li>
128 *
129 * <li><p> <a name="build">{@code $BUILD}</a>, matching {@code
130 * (0|[1-9][0-9]*)} --- The build number, incremented for each promoted build.
131 * {@code $BUILD} is reset to {@code 1} when any portion of {@code $VNUM} is
132 * incremented. </p>
133 *
134 * <p> When comparing two version strings with equal {@code $VNUM} and
135 * {@code $PRE} components, a string without a {@code $BUILD}
136 * component is always less than one with a {@code $BUILD} component;
137 * otherwise, {@code $BUILD} numbers are compared numerically. </p></li>
138 *
139 * <li><p> <a name="opt">{@code $OPT}</a>, matching {@code ([-a-zA-Z0-9\.]+)}
140 * --- Additional build information, if desired. In the case of an {@code
141 * internal} build this will often contain the date and time of the
142 * build. </p>
143 *
144 * <p> When comparing two version strings the value of {@code $OPT}, if
145 * present, is always ignored. </p></li>
146 *
147 * </ul>
148 *
149 * <p> A <em>short version string</em> ({@code $SVSTR}), often useful in less
150 * formal contexts, is simply {@code $VNUM} optionally ended with {@code
151 * -$PRE}. </p>
152 *
153 * @see <a href="http://openjdk.java.net/jeps/223">JEP 223: New Version-String Scheme</a>
154 *
155 * @since 9
156 */
157 public class Version
158 implements Comparable<Version>
159 {
160 private final List<Integer> version;
161 private final Optional<String> pre;
162 private final Optional<Integer> build;
163 private final Optional<String> optional;
164
165 // $VNUM(-$PRE)?(\+$BUILD)?(\-$OPT)?
166 // ([1-9][0-9]*(((\.0)*\.[1-9][0-9]*)*)*)(\-([a-zA-Z0-9]+))?((\+)(0|[1-9][0-9]*)?)?(-([\-a-zA-Z0-9\.]+))?
167
168 private static final String VNUM
169 = "([1-9][0-9]*(((\\.0)*\\.[1-9][0-9]*)*)*)";
170 private static final int VNUM_GROUP = 1;
171
172 private static final String PRE = "(\\-([a-zA-Z0-9]+))?";
173 private static final int PRE_GROUP = 6;
174
175 private static final String BUILD = "((\\+)(0|[1-9][0-9]*)?)?";
176 private static final int PLUS_GROUP = 8;
177 private static final int BUILD_GROUP = 9;
178
179 private static final String OPT = "(-([\\-a-zA-Z0-9\\.]+))?";
180 private static final int OPT_GROUP = 11;
181
182 private static final String VSTR_FORMAT
183 = "^" + VNUM + PRE + BUILD + OPT + "$";
184 private static final Pattern VSTR_PATTERN = Pattern.compile(VSTR_FORMAT);
185
186 /**
187 * Constructs a valid JDK <a href="verStr">version string</a> containing a
188 * <a href="#verNum">version number</a> followed by pre-release and build
189 * information.
190 *
191 * @param s
192 * A string to be interpreted as a version
193 *
194 * @throws IllegalArgumentException
195 * If the given string cannot be interpreted a valid version
196 *
197 * @throws NullPointerException
198 * If {@code s} is {@code null}
199 *
200 * @throws NumberFormatException
201 * If an element of the version number or the build number cannot
202 * be represented as an {@link Integer}
203 */
204 Version(String s) {
205 if (s == null)
206 throw new NullPointerException();
207
208 Matcher m = VSTR_PATTERN.matcher(s);
209 if (!m.matches())
210 throw new IllegalArgumentException("Invalid version string: '"
211 + s + "'");
212
213 version
214 = Collections.unmodifiableList(
215 Arrays.stream(m.group(VNUM_GROUP).split("\\."))
216 .map(Integer::parseInt)
217 .collect(Collectors.toList()));
218
219 pre = Optional.ofNullable(m.group(PRE_GROUP));
220
221 String b = m.group(BUILD_GROUP);
222 build = (b == null)
223 ? Optional.<Integer>empty()
224 : Optional.ofNullable(Integer.parseInt(b));
225 optional = Optional.ofNullable(m.group(OPT_GROUP));
226
227 if ((m.group(PLUS_GROUP) != null)
228 && !build.isPresent() && !optional.isPresent()) {
229 throw new IllegalArgumentException("Terminal '+': '" + s + "'");
230 }
231 }
232
233 /**
234 * Parses the given string as a valid JDK <a
235 * href="#verStr">version string</a> containing a <a
236 * href="#verNum">version number</a> followed by pre-release and
237 * build information.
238 *
239 * @param s
240 * A string to interpret as a version
241 *
242 * @throws IllegalArgumentException
243 * If the given string cannot be interpreted a valid version
244 *
245 * @throws NullPointerException
246 * If the given string is {@code null}
247 *
248 * @throws NumberFormatException
249 * If an element of the version number or the build number cannot
250 * be represented as an {@link Integer}
251 *
252 * @return This version
253 */
254 public static Version parse(String s) {
255 return new Version(s);
256 }
257
258 /**
259 * Returns {@code System.getProperty("java.version")} as a Version.
260 *
261 * @return {@code System.getProperty("java.version")} as a Version
262 */
263 public static Version current() {
264 return parse(System.getProperty("java.version"));
265 }
266
267 /**
268 * Returns the <a href="#major">major</a> version number.
269 *
270 * @return The major version number
271 */
272 public int major() {
273 return version.get(0);
274 }
275
276 /**
277 * Returns the <a href="#minor">minor</a> version number or zero if it was
278 * not set.
279 *
280 * @return The minor version number or zero if it was not set
281 */
282 public int minor() {
283 return (version.size() > 1 ? version.get(1) : 0);
284 }
285
286 /**
287 * Returns the <a href="#security">security</a> version number or zero if
288 * it was not set.
289 *
290 * @return The security version number or zero if it was not set
291 */
292 public int security() {
293 return (version.size() > 2 ? version.get(2) : 0);
294 }
295
296 /**
297 * Returns an unmodifiable {@link java.util.List List} of the
298 * integer numerals contained in the <a href="#verNum">version
299 * number</a>. The {@code List} always contains at least one
300 * element corresponding to the <a href="#major">major version
301 * number</a>.
302 *
303 * @return An unmodifiable list of the integer numerals
304 * contained in the version number
305 */
306 public List<Integer> version() {
307 return version;
308 }
309
310 /**
311 * Returns the optional <a href="#pre">pre-release</a> information.
312 *
313 * @return The optional pre-release information as a String
314 */
315 public Optional<String> pre() {
316 return pre;
317 }
318
319 /**
320 * Returns the <a href="#build">build number</a>.
321 *
322 * @return The optional build number.
323 */
324 public Optional<Integer> build() {
325 return build;
326 }
327
328 /**
329 * Returns <a href="#opt">optional</a> additional identifying build
330 * information.
331 *
332 * @return Additional build information as a String
333 */
334 public Optional<String> optional() {
335 return optional;
336 }
337
338 /**
339 * Compares this version to another.
340 *
341 * <p> Two versions are compared by examining the sequence of version
342 * numbers. If one sequence is shorter than another, then the missing
343 * elements of the shorter sequence are considered to be zero. If the
344 * version numbers are equal, then a version with a pre-release identifier
345 * is always considered to be less than a version without one.
346 * Pre-release identifiers are compared numerically when they consist only
347 * of digits, and lexiographically otherwise. Numeric identifiers are
348 * considered to be less than non-numeric identifiers. A version without
349 * a build value is always less than one with a build value; otherwise
350 * build numbers are compared numerically. The optional build information
351 * is always ignored.
352 *
353 * <p> A version is not comparable to any other type of object.
354 *
355 * @param ob
356 * The object to be compared
357 *
358 * @return A negative integer, zero, or a positive integer if this
359 * {@code Version} is less than, equal to, or greater than the
360 * given {@code Version}
361 *
362 * @throws NullPointerException
363 * If the given object is {@code null}
364 */
365 @Override
366 public int compareTo(Version ob) {
367 if (ob == null)
368 throw new NullPointerException("Invalid argument");
369
370 // $VNUM
371 int size = version.size();
372 int oSize = ob.version().size();
373 int min = Math.min(size, oSize);
374 for (int i = 0; i < min; i++) {
375 Integer val = version.get(i);
376 Integer oVal = ob.version().get(i);
377 if (val != oVal)
378 return val - oVal;
379 }
380 if (size != oSize)
381 return size - oSize;
382
383 // $PRE
384 Optional<String> oPre = ob.pre();
385 if (!pre.isPresent()) {
386 if (oPre.isPresent())
387 return 1;
388 } else {
389 if (!oPre.isPresent())
390 return -1;
391 String val = pre.get();
392 String oVal = oPre.get();
393 if (val.matches("\\d+")) {
394 if (oVal.matches("\\d+")) {
395 return
396 (new BigInteger(val)).compareTo(new BigInteger(oVal));
397 } else {
398 return -1;
399 }
400 } else {
401 if (oVal.matches("\\d+")) {
402 return 1;
403 } else {
404 return val.compareTo(oVal);
405 }
406 }
407 }
408
409 // $BUILD
410 Optional<Integer> oBuild = ob.build();
411 if (oBuild.isPresent()) {
412 return (build.isPresent()
413 ? build.get().compareTo(oBuild.get())
414 : 1);
415 } else if (build.isPresent()) {
416 return -1;
417 }
418
419 return 0;
420 }
421
422 /**
423 * Returns a string representation of this version.
424 *
425 * @return The version string
426 */
427 @Override
428 public String toString() {
429 StringBuilder sb
430 = new StringBuilder(version.stream()
431 .map(Object::toString)
432 .collect(Collectors.joining(".")));
433 if (pre.isPresent())
434 sb.append("-").append(pre.get());
435
436 if (build.isPresent()) {
437 sb.append("+").append(build.get());
438 if (optional.isPresent())
439 sb.append("-").append(optional.get());
440 } else {
441 if (optional.isPresent())
442 sb.append("+-").append(optional.get());
443 }
444
445 return sb.toString();
446 }
447
448 /**
449 * Determines whether this {@code Version} is equal to another object.
450 *
451 * <p> Two {@code Version}s are equal if and only if they represent the
452 * same version string.
453 *
454 * <p> This method satisfies the general contract of the {@link
455 * Object#equals(Object) Object.equals} method. </p>
456 *
457 * @param ob
458 * The object to which this {@code Version} is to be compared
459 *
460 * @return {@code true} if, and only if, the given object is a {@code
461 * Version} that is identical to this {@code Version}
462 *
463 */
464 @Override
465 public boolean equals(Object ob) {
466 if (this == ob)
467 return true;
468 if (!(ob instanceof Version))
469 return false;
470
471 Version that = (Version)ob;
472 return (this.version().equals(that.version())
473 && this.pre().equals(that.pre())
474 && this.build().equals(that.build())
475 && this.optional().equals(that.optional()));
476 }
477
478 /**
479 * Returns the hash code of this version.
480 *
481 * <p> This method satisfies the general contract of the {@link
482 * Object#hashCode Object.hashCode} method.
483 *
484 * @return The hashcode of this version
485 */
486 @Override
487 public int hashCode() {
488 int h = 1;
489 int p = 17;
490
491 h = p * h + version.hashCode();
492 h = p * h + pre.hashCode();
493 h = p * h + build.hashCode();
494 h = p * h + optional.hashCode();
495
496 return h;
497 }
498 }