1 /*
2 * Copyright (c) 1995, 2018, 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 java.lang;
27
28 import java.io.*;
29 import java.math.BigInteger;
30 import java.util.ArrayList;
31 import java.util.regex.Matcher;
32 import java.util.regex.Pattern;
33 import java.util.stream.Collectors;
34 import java.util.Collections;
35 import java.util.List;
36 import java.util.Optional;
37 import java.util.StringTokenizer;
38 import jdk.internal.reflect.CallerSensitive;
39 import jdk.internal.reflect.Reflection;
40
41 /**
42 * Every Java application has a single instance of class
43 * {@code Runtime} that allows the application to interface with
44 * the environment in which the application is running. The current
45 * runtime can be obtained from the {@code getRuntime} method.
46 * <p>
47 * An application cannot create its own instance of this class.
48 *
49 * @author unascribed
50 * @see java.lang.Runtime#getRuntime()
51 * @since 1.0
52 */
53
54 public class Runtime {
55 private static final Runtime currentRuntime = new Runtime();
56
57 private static Version version;
58
59 /**
60 * Returns the runtime object associated with the current Java application.
61 * Most of the methods of class {@code Runtime} are instance
62 * methods and must be invoked with respect to the current runtime object.
63 *
64 * @return the {@code Runtime} object associated with the current
65 * Java application.
66 */
67 public static Runtime getRuntime() {
68 return currentRuntime;
69 }
70
71 /** Don't let anyone else instantiate this class */
72 private Runtime() {}
73
74 /**
75 * Terminates the currently running Java virtual machine by initiating its
76 * shutdown sequence. This method never returns normally. The argument
77 * serves as a status code; by convention, a nonzero status code indicates
78 * abnormal termination.
79 *
80 * <p> The virtual machine's shutdown sequence consists of two phases. In
81 * the first phase all registered {@link #addShutdownHook shutdown hooks},
82 * if any, are started in some unspecified order and allowed to run
83 * concurrently until they finish. In the second phase all uninvoked
84 * finalizers are run if {@link #runFinalizersOnExit finalization-on-exit}
85 * has been enabled. Once this is done the virtual machine {@link #halt halts}.
86 *
87 * <p> If this method is invoked after the virtual machine has begun its
88 * shutdown sequence then if shutdown hooks are being run this method will
89 * block indefinitely. If shutdown hooks have already been run and on-exit
90 * finalization has been enabled then this method halts the virtual machine
91 * with the given status code if the status is nonzero; otherwise, it
92 * blocks indefinitely.
93 *
94 * <p> The {@link System#exit(int) System.exit} method is the
95 * conventional and convenient means of invoking this method.
96 *
97 * @param status
98 * Termination status. By convention, a nonzero status code
99 * indicates abnormal termination.
100 *
101 * @throws SecurityException
102 * If a security manager is present and its
103 * {@link SecurityManager#checkExit checkExit} method does not permit
104 * exiting with the specified status
105 *
106 * @see java.lang.SecurityException
107 * @see java.lang.SecurityManager#checkExit(int)
108 * @see #addShutdownHook
109 * @see #removeShutdownHook
110 * @see #runFinalizersOnExit
111 * @see #halt(int)
112 */
113 public void exit(int status) {
114 SecurityManager security = System.getSecurityManager();
115 if (security != null) {
116 security.checkExit(status);
117 }
118 Shutdown.exit(status);
119 }
120
121 /**
122 * Registers a new virtual-machine shutdown hook.
123 *
124 * <p> The Java virtual machine <i>shuts down</i> in response to two kinds
125 * of events:
126 *
127 * <ul>
128 *
129 * <li> The program <i>exits</i> normally, when the last non-daemon
130 * thread exits or when the {@link #exit exit} (equivalently,
131 * {@link System#exit(int) System.exit}) method is invoked, or
132 *
133 * <li> The virtual machine is <i>terminated</i> in response to a
134 * user interrupt, such as typing {@code ^C}, or a system-wide event,
135 * such as user logoff or system shutdown.
136 *
137 * </ul>
138 *
139 * <p> A <i>shutdown hook</i> is simply an initialized but unstarted
140 * thread. When the virtual machine begins its shutdown sequence it will
141 * start all registered shutdown hooks in some unspecified order and let
142 * them run concurrently. When all the hooks have finished it will then
143 * run all uninvoked finalizers if finalization-on-exit has been enabled.
144 * Finally, the virtual machine will halt. Note that daemon threads will
145 * continue to run during the shutdown sequence, as will non-daemon threads
146 * if shutdown was initiated by invoking the {@link #exit exit} method.
147 *
148 * <p> Once the shutdown sequence has begun it can be stopped only by
149 * invoking the {@link #halt halt} method, which forcibly
150 * terminates the virtual machine.
151 *
152 * <p> Once the shutdown sequence has begun it is impossible to register a
153 * new shutdown hook or de-register a previously-registered hook.
154 * Attempting either of these operations will cause an
155 * {@link IllegalStateException} to be thrown.
156 *
157 * <p> Shutdown hooks run at a delicate time in the life cycle of a virtual
158 * machine and should therefore be coded defensively. They should, in
159 * particular, be written to be thread-safe and to avoid deadlocks insofar
160 * as possible. They should also not rely blindly upon services that may
161 * have registered their own shutdown hooks and therefore may themselves in
162 * the process of shutting down. Attempts to use other thread-based
163 * services such as the AWT event-dispatch thread, for example, may lead to
164 * deadlocks.
165 *
166 * <p> Shutdown hooks should also finish their work quickly. When a
167 * program invokes {@link #exit exit} the expectation is
168 * that the virtual machine will promptly shut down and exit. When the
169 * virtual machine is terminated due to user logoff or system shutdown the
170 * underlying operating system may only allow a fixed amount of time in
171 * which to shut down and exit. It is therefore inadvisable to attempt any
172 * user interaction or to perform a long-running computation in a shutdown
173 * hook.
174 *
175 * <p> Uncaught exceptions are handled in shutdown hooks just as in any
176 * other thread, by invoking the
177 * {@link ThreadGroup#uncaughtException uncaughtException} method of the
178 * thread's {@link ThreadGroup} object. The default implementation of this
179 * method prints the exception's stack trace to {@link System#err} and
180 * terminates the thread; it does not cause the virtual machine to exit or
181 * halt.
182 *
183 * <p> In rare circumstances the virtual machine may <i>abort</i>, that is,
184 * stop running without shutting down cleanly. This occurs when the
185 * virtual machine is terminated externally, for example with the
186 * {@code SIGKILL} signal on Unix or the {@code TerminateProcess} call on
187 * Microsoft Windows. The virtual machine may also abort if a native
188 * method goes awry by, for example, corrupting internal data structures or
189 * attempting to access nonexistent memory. If the virtual machine aborts
190 * then no guarantee can be made about whether or not any shutdown hooks
191 * will be run.
192 *
193 * @param hook
194 * An initialized but unstarted {@link Thread} object
195 *
196 * @throws IllegalArgumentException
197 * If the specified hook has already been registered,
198 * or if it can be determined that the hook is already running or
199 * has already been run
200 *
201 * @throws IllegalStateException
202 * If the virtual machine is already in the process
203 * of shutting down
204 *
205 * @throws SecurityException
206 * If a security manager is present and it denies
207 * {@link RuntimePermission}("shutdownHooks")
208 *
209 * @see #removeShutdownHook
210 * @see #halt(int)
211 * @see #exit(int)
212 * @since 1.3
213 */
214 public void addShutdownHook(Thread hook) {
215 SecurityManager sm = System.getSecurityManager();
216 if (sm != null) {
217 sm.checkPermission(new RuntimePermission("shutdownHooks"));
218 }
219 ApplicationShutdownHooks.add(hook);
220 }
221
222 /**
223 * De-registers a previously-registered virtual-machine shutdown hook.
224 *
225 * @param hook the hook to remove
226 * @return {@code true} if the specified hook had previously been
227 * registered and was successfully de-registered, {@code false}
228 * otherwise.
229 *
230 * @throws IllegalStateException
231 * If the virtual machine is already in the process of shutting
232 * down
233 *
234 * @throws SecurityException
235 * If a security manager is present and it denies
236 * {@link RuntimePermission}("shutdownHooks")
237 *
238 * @see #addShutdownHook
239 * @see #exit(int)
240 * @since 1.3
241 */
242 public boolean removeShutdownHook(Thread hook) {
243 SecurityManager sm = System.getSecurityManager();
244 if (sm != null) {
245 sm.checkPermission(new RuntimePermission("shutdownHooks"));
246 }
247 return ApplicationShutdownHooks.remove(hook);
248 }
249
250 /**
251 * Forcibly terminates the currently running Java virtual machine. This
252 * method never returns normally.
253 *
254 * <p> This method should be used with extreme caution. Unlike the
255 * {@link #exit exit} method, this method does not cause shutdown
256 * hooks to be started and does not run uninvoked finalizers if
257 * finalization-on-exit has been enabled. If the shutdown sequence has
258 * already been initiated then this method does not wait for any running
259 * shutdown hooks or finalizers to finish their work.
260 *
261 * @param status
262 * Termination status. By convention, a nonzero status code
263 * indicates abnormal termination. If the {@link Runtime#exit exit}
264 * (equivalently, {@link System#exit(int) System.exit}) method
265 * has already been invoked then this status code
266 * will override the status code passed to that method.
267 *
268 * @throws SecurityException
269 * If a security manager is present and its
270 * {@link SecurityManager#checkExit checkExit} method
271 * does not permit an exit with the specified status
272 *
273 * @see #exit
274 * @see #addShutdownHook
275 * @see #removeShutdownHook
276 * @since 1.3
277 */
278 public void halt(int status) {
279 SecurityManager sm = System.getSecurityManager();
280 if (sm != null) {
281 sm.checkExit(status);
282 }
283 Shutdown.halt(status);
284 }
285
286 /**
287 * Enable or disable finalization on exit; doing so specifies that the
288 * finalizers of all objects that have finalizers that have not yet been
289 * automatically invoked are to be run before the Java runtime exits.
290 * By default, finalization on exit is disabled.
291 *
292 * <p>If there is a security manager,
293 * its {@code checkExit} method is first called
294 * with 0 as its argument to ensure the exit is allowed.
295 * This could result in a SecurityException.
296 *
297 * @param value true to enable finalization on exit, false to disable
298 * @deprecated This method is inherently unsafe. It may result in
299 * finalizers being called on live objects while other threads are
300 * concurrently manipulating those objects, resulting in erratic
301 * behavior or deadlock.
302 * This method is subject to removal in a future version of Java SE.
303 *
304 * @throws SecurityException
305 * if a security manager exists and its {@code checkExit}
306 * method doesn't allow the exit.
307 *
308 * @see java.lang.Runtime#exit(int)
309 * @see java.lang.Runtime#gc()
310 * @see java.lang.SecurityManager#checkExit(int)
311 * @since 1.1
312 */
313 @Deprecated(since="1.2", forRemoval=true)
314 public static void runFinalizersOnExit(boolean value) {
315 SecurityManager security = System.getSecurityManager();
316 if (security != null) {
317 try {
318 security.checkExit(0);
319 } catch (SecurityException e) {
320 throw new SecurityException("runFinalizersOnExit");
321 }
322 }
323 Shutdown.setRunFinalizersOnExit(value);
324 }
325
326 /**
327 * Executes the specified string command in a separate process.
328 *
329 * <p>This is a convenience method. An invocation of the form
330 * {@code exec(command)}
331 * behaves in exactly the same way as the invocation
332 * {@link #exec(String, String[], File) exec}{@code (command, null, null)}.
333 *
334 * @param command a specified system command.
335 *
336 * @return A new {@link Process} object for managing the subprocess
337 *
338 * @throws SecurityException
339 * If a security manager exists and its
340 * {@link SecurityManager#checkExec checkExec}
341 * method doesn't allow creation of the subprocess
342 *
343 * @throws IOException
344 * If an I/O error occurs
345 *
346 * @throws NullPointerException
347 * If {@code command} is {@code null}
348 *
349 * @throws IllegalArgumentException
350 * If {@code command} is empty
351 *
352 * @see #exec(String[], String[], File)
353 * @see ProcessBuilder
354 */
355 public Process exec(String command) throws IOException {
356 return exec(command, null, null);
357 }
358
359 /**
360 * Executes the specified string command in a separate process with the
361 * specified environment.
362 *
363 * <p>This is a convenience method. An invocation of the form
364 * {@code exec(command, envp)}
365 * behaves in exactly the same way as the invocation
366 * {@link #exec(String, String[], File) exec}{@code (command, envp, null)}.
367 *
368 * @param command a specified system command.
369 *
370 * @param envp array of strings, each element of which
371 * has environment variable settings in the format
372 * <i>name</i>=<i>value</i>, or
373 * {@code null} if the subprocess should inherit
374 * the environment of the current process.
375 *
376 * @return A new {@link Process} object for managing the subprocess
377 *
378 * @throws SecurityException
379 * If a security manager exists and its
380 * {@link SecurityManager#checkExec checkExec}
381 * method doesn't allow creation of the subprocess
382 *
383 * @throws IOException
384 * If an I/O error occurs
385 *
386 * @throws NullPointerException
387 * If {@code command} is {@code null},
388 * or one of the elements of {@code envp} is {@code null}
389 *
390 * @throws IllegalArgumentException
391 * If {@code command} is empty
392 *
393 * @see #exec(String[], String[], File)
394 * @see ProcessBuilder
395 */
396 public Process exec(String command, String[] envp) throws IOException {
397 return exec(command, envp, null);
398 }
399
400 /**
401 * Executes the specified string command in a separate process with the
402 * specified environment and working directory.
403 *
404 * <p>This is a convenience method. An invocation of the form
405 * {@code exec(command, envp, dir)}
406 * behaves in exactly the same way as the invocation
407 * {@link #exec(String[], String[], File) exec}{@code (cmdarray, envp, dir)},
408 * where {@code cmdarray} is an array of all the tokens in
409 * {@code command}.
410 *
411 * <p>More precisely, the {@code command} string is broken
412 * into tokens using a {@link StringTokenizer} created by the call
413 * {@code new {@link StringTokenizer}(command)} with no
414 * further modification of the character categories. The tokens
415 * produced by the tokenizer are then placed in the new string
416 * array {@code cmdarray}, in the same order.
417 *
418 * @param command a specified system command.
419 *
420 * @param envp array of strings, each element of which
421 * has environment variable settings in the format
422 * <i>name</i>=<i>value</i>, or
423 * {@code null} if the subprocess should inherit
424 * the environment of the current process.
425 *
426 * @param dir the working directory of the subprocess, or
427 * {@code null} if the subprocess should inherit
428 * the working directory of the current process.
429 *
430 * @return A new {@link Process} object for managing the subprocess
431 *
432 * @throws SecurityException
433 * If a security manager exists and its
434 * {@link SecurityManager#checkExec checkExec}
435 * method doesn't allow creation of the subprocess
436 *
437 * @throws IOException
438 * If an I/O error occurs
439 *
440 * @throws NullPointerException
441 * If {@code command} is {@code null},
442 * or one of the elements of {@code envp} is {@code null}
443 *
444 * @throws IllegalArgumentException
445 * If {@code command} is empty
446 *
447 * @see ProcessBuilder
448 * @since 1.3
449 */
450 public Process exec(String command, String[] envp, File dir)
451 throws IOException {
452 if (command.length() == 0)
453 throw new IllegalArgumentException("Empty command");
454
455 StringTokenizer st = new StringTokenizer(command);
456 String[] cmdarray = new String[st.countTokens()];
457 for (int i = 0; st.hasMoreTokens(); i++)
458 cmdarray[i] = st.nextToken();
459 return exec(cmdarray, envp, dir);
460 }
461
462 /**
463 * Executes the specified command and arguments in a separate process.
464 *
465 * <p>This is a convenience method. An invocation of the form
466 * {@code exec(cmdarray)}
467 * behaves in exactly the same way as the invocation
468 * {@link #exec(String[], String[], File) exec}{@code (cmdarray, null, null)}.
469 *
470 * @param cmdarray array containing the command to call and
471 * its arguments.
472 *
473 * @return A new {@link Process} object for managing the subprocess
474 *
475 * @throws SecurityException
476 * If a security manager exists and its
477 * {@link SecurityManager#checkExec checkExec}
478 * method doesn't allow creation of the subprocess
479 *
480 * @throws IOException
481 * If an I/O error occurs
482 *
483 * @throws NullPointerException
484 * If {@code cmdarray} is {@code null},
485 * or one of the elements of {@code cmdarray} is {@code null}
486 *
487 * @throws IndexOutOfBoundsException
488 * If {@code cmdarray} is an empty array
489 * (has length {@code 0})
490 *
491 * @see ProcessBuilder
492 */
493 public Process exec(String cmdarray[]) throws IOException {
494 return exec(cmdarray, null, null);
495 }
496
497 /**
498 * Executes the specified command and arguments in a separate process
499 * with the specified environment.
500 *
501 * <p>This is a convenience method. An invocation of the form
502 * {@code exec(cmdarray, envp)}
503 * behaves in exactly the same way as the invocation
504 * {@link #exec(String[], String[], File) exec}{@code (cmdarray, envp, null)}.
505 *
506 * @param cmdarray array containing the command to call and
507 * its arguments.
508 *
509 * @param envp array of strings, each element of which
510 * has environment variable settings in the format
511 * <i>name</i>=<i>value</i>, or
512 * {@code null} if the subprocess should inherit
513 * the environment of the current process.
514 *
515 * @return A new {@link Process} object for managing the subprocess
516 *
517 * @throws SecurityException
518 * If a security manager exists and its
519 * {@link SecurityManager#checkExec checkExec}
520 * method doesn't allow creation of the subprocess
521 *
522 * @throws IOException
523 * If an I/O error occurs
524 *
525 * @throws NullPointerException
526 * If {@code cmdarray} is {@code null},
527 * or one of the elements of {@code cmdarray} is {@code null},
528 * or one of the elements of {@code envp} is {@code null}
529 *
530 * @throws IndexOutOfBoundsException
531 * If {@code cmdarray} is an empty array
532 * (has length {@code 0})
533 *
534 * @see ProcessBuilder
535 */
536 public Process exec(String[] cmdarray, String[] envp) throws IOException {
537 return exec(cmdarray, envp, null);
538 }
539
540
541 /**
542 * Executes the specified command and arguments in a separate process with
543 * the specified environment and working directory.
544 *
545 * <p>Given an array of strings {@code cmdarray}, representing the
546 * tokens of a command line, and an array of strings {@code envp},
547 * representing "environment" variable settings, this method creates
548 * a new process in which to execute the specified command.
549 *
550 * <p>This method checks that {@code cmdarray} is a valid operating
551 * system command. Which commands are valid is system-dependent,
552 * but at the very least the command must be a non-empty list of
553 * non-null strings.
554 *
555 * <p>If {@code envp} is {@code null}, the subprocess inherits the
556 * environment settings of the current process.
557 *
558 * <p>A minimal set of system dependent environment variables may
559 * be required to start a process on some operating systems.
560 * As a result, the subprocess may inherit additional environment variable
561 * settings beyond those in the specified environment.
562 *
563 * <p>{@link ProcessBuilder#start()} is now the preferred way to
564 * start a process with a modified environment.
565 *
566 * <p>The working directory of the new subprocess is specified by {@code dir}.
567 * If {@code dir} is {@code null}, the subprocess inherits the
568 * current working directory of the current process.
569 *
570 * <p>If a security manager exists, its
571 * {@link SecurityManager#checkExec checkExec}
572 * method is invoked with the first component of the array
573 * {@code cmdarray} as its argument. This may result in a
574 * {@link SecurityException} being thrown.
575 *
576 * <p>Starting an operating system process is highly system-dependent.
577 * Among the many things that can go wrong are:
578 * <ul>
579 * <li>The operating system program file was not found.
580 * <li>Access to the program file was denied.
581 * <li>The working directory does not exist.
582 * </ul>
583 *
584 * <p>In such cases an exception will be thrown. The exact nature
585 * of the exception is system-dependent, but it will always be a
586 * subclass of {@link IOException}.
587 *
588 * <p>If the operating system does not support the creation of
589 * processes, an {@link UnsupportedOperationException} will be thrown.
590 *
591 *
592 * @param cmdarray array containing the command to call and
593 * its arguments.
594 *
595 * @param envp array of strings, each element of which
596 * has environment variable settings in the format
597 * <i>name</i>=<i>value</i>, or
598 * {@code null} if the subprocess should inherit
599 * the environment of the current process.
600 *
601 * @param dir the working directory of the subprocess, or
602 * {@code null} if the subprocess should inherit
603 * the working directory of the current process.
604 *
605 * @return A new {@link Process} object for managing the subprocess
606 *
607 * @throws SecurityException
608 * If a security manager exists and its
609 * {@link SecurityManager#checkExec checkExec}
610 * method doesn't allow creation of the subprocess
611 *
612 * @throws UnsupportedOperationException
613 * If the operating system does not support the creation of processes.
614 *
615 * @throws IOException
616 * If an I/O error occurs
617 *
618 * @throws NullPointerException
619 * If {@code cmdarray} is {@code null},
620 * or one of the elements of {@code cmdarray} is {@code null},
621 * or one of the elements of {@code envp} is {@code null}
622 *
623 * @throws IndexOutOfBoundsException
624 * If {@code cmdarray} is an empty array
625 * (has length {@code 0})
626 *
627 * @see ProcessBuilder
628 * @since 1.3
629 */
630 public Process exec(String[] cmdarray, String[] envp, File dir)
631 throws IOException {
632 return new ProcessBuilder(cmdarray)
633 .environment(envp)
634 .directory(dir)
635 .start();
636 }
637
638 /**
639 * Returns the number of processors available to the Java virtual machine.
640 *
641 * <p> This value may change during a particular invocation of the virtual
642 * machine. Applications that are sensitive to the number of available
643 * processors should therefore occasionally poll this property and adjust
644 * their resource usage appropriately. </p>
645 *
646 * @return the maximum number of processors available to the virtual
647 * machine; never smaller than one
648 * @since 1.4
649 */
650 public native int availableProcessors();
651
652 /**
653 * Returns the amount of free memory in the Java Virtual Machine.
654 * Calling the
655 * {@code gc} method may result in increasing the value returned
656 * by {@code freeMemory.}
657 *
658 * @return an approximation to the total amount of memory currently
659 * available for future allocated objects, measured in bytes.
660 */
661 public native long freeMemory();
662
663 /**
664 * Returns the total amount of memory in the Java virtual machine.
665 * The value returned by this method may vary over time, depending on
666 * the host environment.
667 * <p>
668 * Note that the amount of memory required to hold an object of any
669 * given type may be implementation-dependent.
670 *
671 * @return the total amount of memory currently available for current
672 * and future objects, measured in bytes.
673 */
674 public native long totalMemory();
675
676 /**
677 * Returns the maximum amount of memory that the Java virtual machine
678 * will attempt to use. If there is no inherent limit then the value
679 * {@link java.lang.Long#MAX_VALUE} will be returned.
680 *
681 * @return the maximum amount of memory that the virtual machine will
682 * attempt to use, measured in bytes
683 * @since 1.4
684 */
685 public native long maxMemory();
686
687 /**
688 * Runs the garbage collector.
689 * Calling this method suggests that the Java virtual machine expend
690 * effort toward recycling unused objects in order to make the memory
691 * they currently occupy available for quick reuse. When control
692 * returns from the method call, the virtual machine has made
693 * its best effort to recycle all discarded objects.
694 * <p>
695 * The name {@code gc} stands for "garbage
696 * collector". The virtual machine performs this recycling
697 * process automatically as needed, in a separate thread, even if the
698 * {@code gc} method is not invoked explicitly.
699 * <p>
700 * The method {@link System#gc()} is the conventional and convenient
701 * means of invoking this method.
702 */
703 public native void gc();
704
705 /* Wormhole for calling java.lang.ref.Finalizer.runFinalization */
706 private static native void runFinalization0();
707
708 /**
709 * Runs the finalization methods of any objects pending finalization.
710 * Calling this method suggests that the Java virtual machine expend
711 * effort toward running the {@code finalize} methods of objects
712 * that have been found to be discarded but whose {@code finalize}
713 * methods have not yet been run. When control returns from the
714 * method call, the virtual machine has made a best effort to
715 * complete all outstanding finalizations.
716 * <p>
717 * The virtual machine performs the finalization process
718 * automatically as needed, in a separate thread, if the
719 * {@code runFinalization} method is not invoked explicitly.
720 * <p>
721 * The method {@link System#runFinalization()} is the conventional
722 * and convenient means of invoking this method.
723 *
724 * @see java.lang.Object#finalize()
725 */
726 public void runFinalization() {
727 runFinalization0();
728 }
729
730 /**
731 * Not implemented, does nothing.
732 *
733 * @deprecated
734 * This method was intended to control instruction tracing.
735 * It has been superseded by JVM-specific tracing mechanisms.
736 * This method is subject to removal in a future version of Java SE.
737 *
738 * @param on ignored
739 */
740 @Deprecated(since="9", forRemoval=true)
741 public void traceInstructions(boolean on) { }
742
743 /**
744 * Not implemented, does nothing.
745 *
746 * @deprecated
747 * This method was intended to control method call tracing.
748 * It has been superseded by JVM-specific tracing mechanisms.
749 * This method is subject to removal in a future version of Java SE.
750 *
751 * @param on ignored
752 */
753 @Deprecated(since="9", forRemoval=true)
754 public void traceMethodCalls(boolean on) { }
755
756 /**
757 * Loads the native library specified by the filename argument. The filename
758 * argument must be an absolute path name.
759 * (for example
760 * {@code Runtime.getRuntime().load("/home/avh/lib/libX11.so");}).
761 *
762 * If the filename argument, when stripped of any platform-specific library
763 * prefix, path, and file extension, indicates a library whose name is,
764 * for example, L, and a native library called L is statically linked
765 * with the VM, then the JNI_OnLoad_L function exported by the library
766 * is invoked rather than attempting to load a dynamic library.
767 * A filename matching the argument does not have to exist in the file
768 * system.
769 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
770 * for more details.
771 *
772 * Otherwise, the filename argument is mapped to a native library image in
773 * an implementation-dependent manner.
774 * <p>
775 * First, if there is a security manager, its {@code checkLink}
776 * method is called with the {@code filename} as its argument.
777 * This may result in a security exception.
778 * <p>
779 * This is similar to the method {@link #loadLibrary(String)}, but it
780 * accepts a general file name as an argument rather than just a library
781 * name, allowing any file of native code to be loaded.
782 * <p>
783 * The method {@link System#load(String)} is the conventional and
784 * convenient means of invoking this method.
785 *
786 * @param filename the file to load.
787 * @exception SecurityException if a security manager exists and its
788 * {@code checkLink} method doesn't allow
789 * loading of the specified dynamic library
790 * @exception UnsatisfiedLinkError if either the filename is not an
791 * absolute path name, the native library is not statically
792 * linked with the VM, or the library cannot be mapped to
793 * a native library image by the host system.
794 * @exception NullPointerException if {@code filename} is
795 * {@code null}
796 * @see java.lang.Runtime#getRuntime()
797 * @see java.lang.SecurityException
798 * @see java.lang.SecurityManager#checkLink(java.lang.String)
799 */
800 @CallerSensitive
801 public void load(String filename) {
802 load0(Reflection.getCallerClass(), filename);
803 }
804
805 synchronized void load0(Class<?> fromClass, String filename) {
806 SecurityManager security = System.getSecurityManager();
807 if (security != null) {
808 security.checkLink(filename);
809 }
810 if (!(new File(filename).isAbsolute())) {
811 throw new UnsatisfiedLinkError(
812 "Expecting an absolute path of the library: " + filename);
813 }
814 ClassLoader.loadLibrary(fromClass, filename, true);
815 }
816
817 /**
818 * Loads the native library specified by the {@code libname}
819 * argument. The {@code libname} argument must not contain any platform
820 * specific prefix, file extension or path. If a native library
821 * called {@code libname} is statically linked with the VM, then the
822 * JNI_OnLoad_{@code libname} function exported by the library is invoked.
823 * See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
824 * for more details.
825 *
826 * Otherwise, the libname argument is loaded from a system library
827 * location and mapped to a native library image in an implementation-
828 * dependent manner.
829 * <p>
830 * First, if there is a security manager, its {@code checkLink}
831 * method is called with the {@code libname} as its argument.
832 * This may result in a security exception.
833 * <p>
834 * The method {@link System#loadLibrary(String)} is the conventional
835 * and convenient means of invoking this method. If native
836 * methods are to be used in the implementation of a class, a standard
837 * strategy is to put the native code in a library file (call it
838 * {@code LibFile}) and then to put a static initializer:
839 * <blockquote><pre>
840 * static { System.loadLibrary("LibFile"); }
841 * </pre></blockquote>
842 * within the class declaration. When the class is loaded and
843 * initialized, the necessary native code implementation for the native
844 * methods will then be loaded as well.
845 * <p>
846 * If this method is called more than once with the same library
847 * name, the second and subsequent calls are ignored.
848 *
849 * @param libname the name of the library.
850 * @exception SecurityException if a security manager exists and its
851 * {@code checkLink} method doesn't allow
852 * loading of the specified dynamic library
853 * @exception UnsatisfiedLinkError if either the libname argument
854 * contains a file path, the native library is not statically
855 * linked with the VM, or the library cannot be mapped to a
856 * native library image by the host system.
857 * @exception NullPointerException if {@code libname} is
858 * {@code null}
859 * @see java.lang.SecurityException
860 * @see java.lang.SecurityManager#checkLink(java.lang.String)
861 */
862 @CallerSensitive
863 public void loadLibrary(String libname) {
864 loadLibrary0(Reflection.getCallerClass(), libname);
865 }
866
867 synchronized void loadLibrary0(Class<?> fromClass, String libname) {
868 SecurityManager security = System.getSecurityManager();
869 if (security != null) {
870 security.checkLink(libname);
871 }
872 if (libname.indexOf((int)File.separatorChar) != -1) {
873 throw new UnsatisfiedLinkError(
874 "Directory separator should not appear in library name: " + libname);
875 }
876 ClassLoader.loadLibrary(fromClass, libname, false);
877 }
878
879 /**
880 * Returns the version of the Java Runtime Environment as a {@link Version}.
881 *
882 * @return the {@link Version} of the Java Runtime Environment
883 *
884 * @since 9
885 */
886 public static Version version() {
887 if (version == null) {
888 version = new Version(VersionProps.versionNumbers(),
889 VersionProps.pre(), VersionProps.build(),
890 VersionProps.optional());
891 }
892 return version;
893 }
894
895 /**
896 * A representation of a version string for an implementation of the
897 * Java SE Platform. A version string consists of a version number
898 * optionally followed by pre-release and build information.
899 *
900 * <h2><a id="verNum">Version numbers</a></h2>
901 *
902 * <p> A <em>version number</em>, {@code $VNUM}, is a non-empty sequence of
903 * elements separated by period characters (U+002E). An element is either
904 * zero, or an unsigned integer numeral without leading zeros. The final
905 * element in a version number must not be zero. When an element is
906 * incremented, all subsequent elements are removed. The format is: </p>
907 *
908 * <blockquote><pre>
909 * [1-9][0-9]*((\.0)*\.[1-9][0-9]*)*
910 * </pre></blockquote>
911 *
912 * <p> The sequence may be of arbitrary length but the first four elements
913 * are assigned specific meanings, as follows:</p>
914 *
915 * <blockquote><pre>
916 * $FEATURE.$INTERIM.$UPDATE.$PATCH
917 * </pre></blockquote>
918 *
919 * <ul>
920 *
921 * <li><p> <a id="FEATURE">{@code $FEATURE}</a> — The
922 * feature-release counter, incremented for every feature release
923 * regardless of release content. Features may be added in a feature
924 * release; they may also be removed, if advance notice was given at least
925 * one feature release ahead of time. Incompatible changes may be made
926 * when justified. </p></li>
927 *
928 * <li><p> <a id="INTERIM">{@code $INTERIM}</a> — The
929 * interim-release counter, incremented for non-feature releases that
930 * contain compatible bug fixes and enhancements but no incompatible
931 * changes, no feature removals, and no changes to standard APIs.
932 * </p></li>
933 *
934 * <li><p> <a id="UPDATE">{@code $UPDATE}</a> — The update-release
935 * counter, incremented for compatible update releases that fix security
936 * issues, regressions, and bugs in newer features. </p></li>
937 *
938 * <li><p> <a id="PATCH">{@code $PATCH}</a> — The emergency
939 * patch-release counter, incremented only when it's necessary to produce
940 * an emergency release to fix a critical issue. </p></li>
941 *
942 * </ul>
943 *
944 * <p> The fifth and later elements of a version number are free for use by
945 * platform implementors, to identify implementor-specific patch
946 * releases. </p>
947 *
948 * <p> A version number never has trailing zero elements. If an element
949 * and all those that follow it logically have the value zero then all of
950 * them are omitted. </p>
951 *
952 * <p> The sequence of numerals in a version number is compared to another
953 * such sequence in numerical, pointwise fashion; <em>e.g.</em>, {@code
954 * 10.0.4} is less than {@code 10.1.2}. If one sequence is shorter than
955 * another then the missing elements of the shorter sequence are considered
956 * to be less than the corresponding elements of the longer sequence;
957 * <em>e.g.</em>, {@code 10.0.2} is less than {@code 10.0.2.1}. </p>
958 *
959 * <h2><a id="verStr">Version strings</a></h2>
960 *
961 * <p> A <em>version string</em>, {@code $VSTR}, is a version number {@code
962 * $VNUM}, as described above, optionally followed by pre-release and build
963 * information, in one of the following formats: </p>
964 *
965 * <blockquote><pre>
966 * $VNUM(-$PRE)?\+$BUILD(-$OPT)?
967 * $VNUM-$PRE(-$OPT)?
968 * $VNUM(+-$OPT)?
969 * </pre></blockquote>
970 *
971 * <p> where: </p>
972 *
973 * <ul>
974 *
975 * <li><p> <a id="pre">{@code $PRE}</a>, matching {@code ([a-zA-Z0-9]+)}
976 * — A pre-release identifier. Typically {@code ea}, for a
977 * potentially unstable early-access release under active development, or
978 * {@code internal}, for an internal developer build. </p></li>
979 *
980 * <li><p> <a id="build">{@code $BUILD}</a>, matching {@code
981 * (0|[1-9][0-9]*)} — The build number, incremented for each promoted
982 * build. {@code $BUILD} is reset to {@code 1} when any portion of {@code
983 * $VNUM} is incremented. </p></li>
984 *
985 * <li><p> <a id="opt">{@code $OPT}</a>, matching {@code ([-a-zA-Z0-9.]+)}
986 * — Additional build information, if desired. In the case of an
987 * {@code internal} build this will often contain the date and time of the
988 * build. </p></li>
989 *
990 * </ul>
991 *
992 * <p> A version string {@code 10-ea} matches {@code $VNUM = "10"} and
993 * {@code $PRE = "ea"}. The version string {@code 10+-ea} matches
994 * {@code $VNUM = "10"} and {@code $OPT = "ea"}. </p>
995 *
996 * <p> When comparing two version strings, the value of {@code $OPT}, if
997 * present, may or may not be significant depending on the chosen
998 * comparison method. The comparison methods {@link #compareTo(Version)
999 * compareTo()} and {@link #compareToIgnoreOptional(Version)
1000 * compareToIgnoreOptional()} should be used consistently with the
1001 * corresponding methods {@link #equals(Object) equals()} and {@link
1002 * #equalsIgnoreOptional(Object) equalsIgnoreOptional()}. </p>
1003 *
1004 * <p> A <em>short version string</em>, {@code $SVSTR}, often useful in
1005 * less formal contexts, is a version number optionally followed by a
1006 * pre-release identifier:</p>
1007 *
1008 * <blockquote><pre>
1009 * $VNUM(-$PRE)?
1010 * </pre></blockquote>
1011 *
1012 * <p>This is a <a href="./doc-files/ValueBased.html">value-based</a>
1013 * class; use of identity-sensitive operations (including reference equality
1014 * ({@code ==}), identity hash code, or synchronization) on instances of
1015 * {@code Version} may have unpredictable results and should be avoided.
1016 * </p>
1017 *
1018 * @since 9
1019 */
1020 public static final class Version
1021 implements Comparable<Version>
1022 {
1023 private final List<Integer> version;
1024 private final Optional<String> pre;
1025 private final Optional<Integer> build;
1026 private final Optional<String> optional;
1027
1028 /*
1029 * List of version number components passed to this constructor MUST
1030 * be at least unmodifiable (ideally immutable). In the case on an
1031 * unmodifiable list, the caller MUST hand the list over to this
1032 * constructor and never change the underlying list.
1033 */
1034 private Version(List<Integer> unmodifiableListOfVersions,
1035 Optional<String> pre,
1036 Optional<Integer> build,
1037 Optional<String> optional)
1038 {
1039 this.version = unmodifiableListOfVersions;
1040 this.pre = pre;
1041 this.build = build;
1042 this.optional = optional;
1043 }
1044
1045 /**
1046 * Parses the given string as a valid
1047 * <a href="#verStr">version string</a> containing a
1048 * <a href="#verNum">version number</a> followed by pre-release and
1049 * build information.
1050 *
1051 * @param s
1052 * A string to interpret as a version
1053 *
1054 * @throws IllegalArgumentException
1055 * If the given string cannot be interpreted as a valid
1056 * version
1057 *
1058 * @throws NullPointerException
1059 * If the given string is {@code null}
1060 *
1061 * @throws NumberFormatException
1062 * If an element of the version number or the build number
1063 * cannot be represented as an {@link Integer}
1064 *
1065 * @return The Version of the given string
1066 */
1067 public static Version parse(String s) {
1068 if (s == null)
1069 throw new NullPointerException();
1070
1071 // Shortcut to avoid initializing VersionPattern when creating
1072 // feature-version constants during startup
1073 if (isSimpleNumber(s)) {
1074 return new Version(List.of(Integer.parseInt(s)),
1075 Optional.empty(), Optional.empty(), Optional.empty());
1076 }
1077 Matcher m = VersionPattern.VSTR_PATTERN.matcher(s);
1078 if (!m.matches())
1079 throw new IllegalArgumentException("Invalid version string: '"
1080 + s + "'");
1081
1082 // $VNUM is a dot-separated list of integers of arbitrary length
1083 String[] split = m.group(VersionPattern.VNUM_GROUP).split("\\.");
1084 Integer[] version = new Integer[split.length];
1085 for (int i = 0; i < split.length; i++) {
1086 version[i] = Integer.parseInt(split[i]);
1087 }
1088
1089 Optional<String> pre = Optional.ofNullable(
1090 m.group(VersionPattern.PRE_GROUP));
1091
1092 String b = m.group(VersionPattern.BUILD_GROUP);
1093 // $BUILD is an integer
1094 Optional<Integer> build = (b == null)
1095 ? Optional.empty()
1096 : Optional.of(Integer.parseInt(b));
1097
1098 Optional<String> optional = Optional.ofNullable(
1099 m.group(VersionPattern.OPT_GROUP));
1100
1101 // empty '+'
1102 if (!build.isPresent()) {
1103 if (m.group(VersionPattern.PLUS_GROUP) != null) {
1104 if (optional.isPresent()) {
1105 if (pre.isPresent())
1106 throw new IllegalArgumentException("'+' found with"
1107 + " pre-release and optional components:'" + s
1108 + "'");
1109 } else {
1110 throw new IllegalArgumentException("'+' found with neither"
1111 + " build or optional components: '" + s + "'");
1112 }
1113 } else {
1114 if (optional.isPresent() && !pre.isPresent()) {
1115 throw new IllegalArgumentException("optional component"
1116 + " must be preceeded by a pre-release component"
1117 + " or '+': '" + s + "'");
1118 }
1119 }
1120 }
1121 return new Version(List.of(version), pre, build, optional);
1122 }
1123
1124 private static boolean isSimpleNumber(String s) {
1125 for (int i = 0; i < s.length(); i++) {
1126 char c = s.charAt(i);
1127 char lowerBound = (i > 0) ? '0' : '1';
1128 if (c < lowerBound || c > '9') {
1129 return false;
1130 }
1131 }
1132 return true;
1133 }
1134
1135 /**
1136 * Returns the value of the <a href="#FEATURE">feature</a> element of
1137 * the version number.
1138 *
1139 * @return The value of the feature element
1140 *
1141 * @since 10
1142 */
1143 public int feature() {
1144 return version.get(0);
1145 }
1146
1147 /**
1148 * Returns the value of the <a href="#INTERIM">interim</a> element of
1149 * the version number, or zero if it is absent.
1150 *
1151 * @return The value of the interim element, or zero
1152 *
1153 * @since 10
1154 */
1155 public int interim() {
1156 return (version.size() > 1 ? version.get(1) : 0);
1157 }
1158
1159 /**
1160 * Returns the value of the <a href="#UPDATE">update</a> element of the
1161 * version number, or zero if it is absent.
1162 *
1163 * @return The value of the update element, or zero
1164 *
1165 * @since 10
1166 */
1167 public int update() {
1168 return (version.size() > 2 ? version.get(2) : 0);
1169 }
1170
1171 /**
1172 * Returns the value of the <a href="#PATCH">patch</a> element of the
1173 * version number, or zero if it is absent.
1174 *
1175 * @return The value of the patch element, or zero
1176 *
1177 * @since 10
1178 */
1179 public int patch() {
1180 return (version.size() > 3 ? version.get(3) : 0);
1181 }
1182
1183 /**
1184 * Returns the value of the major element of the version number.
1185 *
1186 * @deprecated As of Java SE 10, the first element of a version
1187 * number is not the major-release number but the feature-release
1188 * counter, incremented for every time-based release. Use the {@link
1189 * #feature()} method in preference to this method. For compatibility,
1190 * this method returns the value of the <a href="FEATURE">feature</a>
1191 * element.
1192 *
1193 * @return The value of the feature element
1194 */
1195 @Deprecated(since = "10")
1196 public int major() {
1197 return feature();
1198 }
1199
1200 /**
1201 * Returns the value of the minor element of the version number, or
1202 * zero if it is absent.
1203 *
1204 * @deprecated As of Java SE 10, the second element of a version
1205 * number is not the minor-release number but the interim-release
1206 * counter, incremented for every interim release. Use the {@link
1207 * #interim()} method in preference to this method. For compatibility,
1208 * this method returns the value of the <a href="INTERIM">interim</a>
1209 * element, or zero if it is absent.
1210 *
1211 * @return The value of the interim element, or zero
1212 */
1213 @Deprecated(since = "10")
1214 public int minor() {
1215 return interim();
1216 }
1217
1218 /**
1219 * Returns the value of the security element of the version number, or
1220 * zero if it is absent.
1221 *
1222 * @deprecated As of Java SE 10, the third element of a version
1223 * number is not the security level but the update-release counter,
1224 * incremented for every update release. Use the {@link #update()}
1225 * method in preference to this method. For compatibility, this method
1226 * returns the value of the <a href="UPDATE">update</a> element, or
1227 * zero if it is absent.
1228 *
1229 * @return The value of the update element, or zero
1230 */
1231 @Deprecated(since = "10")
1232 public int security() {
1233 return update();
1234 }
1235
1236 /**
1237 * Returns an unmodifiable {@link java.util.List List} of the integers
1238 * represented in the <a href="#verNum">version number</a>. The {@code
1239 * List} always contains at least one element corresponding to the <a
1240 * href="#feature">feature version number</a>.
1241 *
1242 * @return An unmodifiable list of the integers
1243 * represented in the version number
1244 */
1245 public List<Integer> version() {
1246 return version;
1247 }
1248
1249 /**
1250 * Returns the optional <a href="#pre">pre-release</a> information.
1251 *
1252 * @return The optional pre-release information as a String
1253 */
1254 public Optional<String> pre() {
1255 return pre;
1256 }
1257
1258 /**
1259 * Returns the <a href="#build">build number</a>.
1260 *
1261 * @return The optional build number.
1262 */
1263 public Optional<Integer> build() {
1264 return build;
1265 }
1266
1267 /**
1268 * Returns <a href="#opt">optional</a> additional identifying build
1269 * information.
1270 *
1271 * @return Additional build information as a String
1272 */
1273 public Optional<String> optional() {
1274 return optional;
1275 }
1276
1277 /**
1278 * Compares this version to another.
1279 *
1280 * <p> Each of the components in the <a href="#verStr">version</a> is
1281 * compared in the following order of precedence: version numbers,
1282 * pre-release identifiers, build numbers, optional build information.
1283 * </p>
1284 *
1285 * <p> Comparison begins by examining the sequence of version numbers.
1286 * If one sequence is shorter than another, then the missing elements
1287 * of the shorter sequence are considered to be less than the
1288 * corresponding elements of the longer sequence. </p>
1289 *
1290 * <p> A version with a pre-release identifier is always considered to
1291 * be less than a version without one. Pre-release identifiers are
1292 * compared numerically when they consist only of digits, and
1293 * lexicographically otherwise. Numeric identifiers are considered to
1294 * be less than non-numeric identifiers. </p>
1295 *
1296 * <p> A version without a build number is always less than one with a
1297 * build number; otherwise build numbers are compared numerically. </p>
1298 *
1299 * <p> The optional build information is compared lexicographically.
1300 * During this comparison, a version with optional build information is
1301 * considered to be greater than a version without one. </p>
1302 *
1303 * @param obj
1304 * The object to be compared
1305 *
1306 * @return A negative integer, zero, or a positive integer if this
1307 * {@code Version} is less than, equal to, or greater than the
1308 * given {@code Version}
1309 *
1310 * @throws NullPointerException
1311 * If the given object is {@code null}
1312 */
1313 @Override
1314 public int compareTo(Version obj) {
1315 return compare(obj, false);
1316 }
1317
1318 /**
1319 * Compares this version to another disregarding optional build
1320 * information.
1321 *
1322 * <p> Two versions are compared by examining the version string as
1323 * described in {@link #compareTo(Version)} with the exception that the
1324 * optional build information is always ignored. </p>
1325 *
1326 * <p> This method provides ordering which is consistent with
1327 * {@code equalsIgnoreOptional()}. </p>
1328 *
1329 * @param obj
1330 * The object to be compared
1331 *
1332 * @return A negative integer, zero, or a positive integer if this
1333 * {@code Version} is less than, equal to, or greater than the
1334 * given {@code Version}
1335 *
1336 * @throws NullPointerException
1337 * If the given object is {@code null}
1338 */
1339 public int compareToIgnoreOptional(Version obj) {
1340 return compare(obj, true);
1341 }
1342
1343 private int compare(Version obj, boolean ignoreOpt) {
1344 if (obj == null)
1345 throw new NullPointerException();
1346
1347 int ret = compareVersion(obj);
1348 if (ret != 0)
1349 return ret;
1350
1351 ret = comparePre(obj);
1352 if (ret != 0)
1353 return ret;
1354
1355 ret = compareBuild(obj);
1356 if (ret != 0)
1357 return ret;
1358
1359 if (!ignoreOpt)
1360 return compareOptional(obj);
1361
1362 return 0;
1363 }
1364
1365 private int compareVersion(Version obj) {
1366 int size = version.size();
1367 int oSize = obj.version().size();
1368 int min = Math.min(size, oSize);
1369 for (int i = 0; i < min; i++) {
1370 int val = version.get(i);
1371 int oVal = obj.version().get(i);
1372 if (val != oVal)
1373 return val - oVal;
1374 }
1375 return size - oSize;
1376 }
1377
1378 private int comparePre(Version obj) {
1379 Optional<String> oPre = obj.pre();
1380 if (!pre.isPresent()) {
1381 if (oPre.isPresent())
1382 return 1;
1383 } else {
1384 if (!oPre.isPresent())
1385 return -1;
1386 String val = pre.get();
1387 String oVal = oPre.get();
1388 if (val.matches("\\d+")) {
1389 return (oVal.matches("\\d+")
1390 ? (new BigInteger(val)).compareTo(new BigInteger(oVal))
1391 : -1);
1392 } else {
1393 return (oVal.matches("\\d+")
1394 ? 1
1395 : val.compareTo(oVal));
1396 }
1397 }
1398 return 0;
1399 }
1400
1401 private int compareBuild(Version obj) {
1402 Optional<Integer> oBuild = obj.build();
1403 if (oBuild.isPresent()) {
1404 return (build.isPresent()
1405 ? build.get().compareTo(oBuild.get())
1406 : -1);
1407 } else if (build.isPresent()) {
1408 return 1;
1409 }
1410 return 0;
1411 }
1412
1413 private int compareOptional(Version obj) {
1414 Optional<String> oOpt = obj.optional();
1415 if (!optional.isPresent()) {
1416 if (oOpt.isPresent())
1417 return -1;
1418 } else {
1419 if (!oOpt.isPresent())
1420 return 1;
1421 return optional.get().compareTo(oOpt.get());
1422 }
1423 return 0;
1424 }
1425
1426 /**
1427 * Returns a string representation of this version.
1428 *
1429 * @return The version string
1430 */
1431 @Override
1432 public String toString() {
1433 StringBuilder sb
1434 = new StringBuilder(version.stream()
1435 .map(Object::toString)
1436 .collect(Collectors.joining(".")));
1437
1438 pre.ifPresent(v -> sb.append("-").append(v));
1439
1440 if (build.isPresent()) {
1441 sb.append("+").append(build.get());
1442 if (optional.isPresent())
1443 sb.append("-").append(optional.get());
1444 } else {
1445 if (optional.isPresent()) {
1446 sb.append(pre.isPresent() ? "-" : "+-");
1447 sb.append(optional.get());
1448 }
1449 }
1450
1451 return sb.toString();
1452 }
1453
1454 /**
1455 * Determines whether this {@code Version} is equal to another object.
1456 *
1457 * <p> Two {@code Version}s are equal if and only if they represent the
1458 * same version string.
1459 *
1460 * @param obj
1461 * The object to which this {@code Version} is to be compared
1462 *
1463 * @return {@code true} if, and only if, the given object is a {@code
1464 * Version} that is identical to this {@code Version}
1465 *
1466 */
1467 @Override
1468 public boolean equals(Object obj) {
1469 boolean ret = equalsIgnoreOptional(obj);
1470 if (!ret)
1471 return false;
1472
1473 Version that = (Version)obj;
1474 return (this.optional().equals(that.optional()));
1475 }
1476
1477 /**
1478 * Determines whether this {@code Version} is equal to another
1479 * disregarding optional build information.
1480 *
1481 * <p> Two {@code Version}s are equal if and only if they represent the
1482 * same version string disregarding the optional build information.
1483 *
1484 * @param obj
1485 * The object to which this {@code Version} is to be compared
1486 *
1487 * @return {@code true} if, and only if, the given object is a {@code
1488 * Version} that is identical to this {@code Version}
1489 * ignoring the optional build information
1490 *
1491 */
1492 public boolean equalsIgnoreOptional(Object obj) {
1493 if (this == obj)
1494 return true;
1495 if (!(obj instanceof Version))
1496 return false;
1497
1498 Version that = (Version)obj;
1499 return (this.version().equals(that.version())
1500 && this.pre().equals(that.pre())
1501 && this.build().equals(that.build()));
1502 }
1503
1504 /**
1505 * Returns the hash code of this version.
1506 *
1507 * @return The hashcode of this version
1508 */
1509 @Override
1510 public int hashCode() {
1511 int h = 1;
1512 int p = 17;
1513
1514 h = p * h + version.hashCode();
1515 h = p * h + pre.hashCode();
1516 h = p * h + build.hashCode();
1517 h = p * h + optional.hashCode();
1518
1519 return h;
1520 }
1521 }
1522
1523 private static class VersionPattern {
1524 // $VNUM(-$PRE)?(\+($BUILD)?(\-$OPT)?)?
1525 // RE limits the format of version strings
1526 // ([1-9][0-9]*(?:(?:\.0)*\.[1-9][0-9]*)*)(?:-([a-zA-Z0-9]+))?(?:(\+)(0|[1-9][0-9]*)?)?(?:-([-a-zA-Z0-9.]+))?
1527
1528 private static final String VNUM
1529 = "(?<VNUM>[1-9][0-9]*(?:(?:\\.0)*\\.[1-9][0-9]*)*)";
1530 private static final String PRE = "(?:-(?<PRE>[a-zA-Z0-9]+))?";
1531 private static final String BUILD
1532 = "(?:(?<PLUS>\\+)(?<BUILD>0|[1-9][0-9]*)?)?";
1533 private static final String OPT = "(?:-(?<OPT>[-a-zA-Z0-9.]+))?";
1534 private static final String VSTR_FORMAT = VNUM + PRE + BUILD + OPT;
1535
1536 static final Pattern VSTR_PATTERN = Pattern.compile(VSTR_FORMAT);
1537
1538 static final String VNUM_GROUP = "VNUM";
1539 static final String PRE_GROUP = "PRE";
1540 static final String PLUS_GROUP = "PLUS";
1541 static final String BUILD_GROUP = "BUILD";
1542 static final String OPT_GROUP = "OPT";
1543 }
1544 }