1 /*
2 * Copyright (c) 1994, 2016, 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 package java.lang;
26
27 import java.io.BufferedInputStream;
28 import java.io.BufferedOutputStream;
29 import java.io.Console;
30 import java.io.FileDescriptor;
31 import java.io.FileInputStream;
32 import java.io.FileOutputStream;
33 import java.io.IOException;
34 import java.io.InputStream;
35 import java.io.PrintStream;
36 import java.io.UnsupportedEncodingException;
37 import java.lang.annotation.Annotation;
38 import java.lang.reflect.Constructor;
39 import java.lang.reflect.Executable;
40 import java.lang.reflect.Layer;
41 import java.lang.reflect.Modifier;
42 import java.lang.reflect.Module;
43 import java.net.URL;
44 import java.security.AccessControlContext;
45 import java.util.Properties;
46 import java.util.PropertyPermission;
47 import java.util.Map;
48 import java.security.AccessController;
49 import java.security.PrivilegedAction;
50 import java.nio.channels.Channel;
51 import java.nio.channels.spi.SelectorProvider;
52 import java.util.concurrent.ConcurrentHashMap;
53 import java.util.stream.Stream;
54
55 import java.util.Objects;
56 import java.util.ResourceBundle;
57 import java.util.function.Supplier;
58 import sun.nio.ch.Interruptible;
59 import sun.reflect.CallerSensitive;
60 import sun.reflect.Reflection;
61 import sun.security.util.SecurityConstants;
62 import sun.reflect.annotation.AnnotationType;
63 import jdk.internal.HotSpotIntrinsicCandidate;
64 import jdk.internal.misc.JavaLangAccess;;
65 import jdk.internal.misc.SharedSecrets;;
66 import jdk.internal.misc.VM;
67 import jdk.internal.logger.LoggerFinderLoader;
68 import jdk.internal.logger.LazyLoggers;
69 import jdk.internal.logger.LocalizedLoggerWrapper;
70
71 import jdk.internal.module.ModuleBootstrap;
72 import jdk.internal.module.Modules;
73 import jdk.internal.module.ServicesCatalog;
74
75 /**
76 * The <code>System</code> class contains several useful class fields
77 * and methods. It cannot be instantiated.
78 *
79 * <p>Among the facilities provided by the <code>System</code> class
80 * are standard input, standard output, and error output streams;
81 * access to externally defined properties and environment
82 * variables; a means of loading files and libraries; and a utility
83 * method for quickly copying a portion of an array.
84 *
85 * @author unascribed
86 * @since 1.0
87 */
88 public final class System {
89 /* register the natives via the static initializer.
90 *
91 * VM will invoke the initializeSystemClass method to complete
92 * the initialization for this class separated from clinit.
93 * Note that to use properties set by the VM, see the constraints
94 * described in the initializeSystemClass method.
95 */
96 private static native void registerNatives();
97 static {
98 registerNatives();
99 }
100
101 /** Don't let anyone instantiate this class */
102 private System() {
103 }
104
105 /**
106 * The "standard" input stream. This stream is already
107 * open and ready to supply input data. Typically this stream
108 * corresponds to keyboard input or another input source specified by
109 * the host environment or user.
110 */
111 public static final InputStream in = null;
112
113 /**
114 * The "standard" output stream. This stream is already
115 * open and ready to accept output data. Typically this stream
116 * corresponds to display output or another output destination
117 * specified by the host environment or user.
118 * <p>
119 * For simple stand-alone Java applications, a typical way to write
120 * a line of output data is:
121 * <blockquote><pre>
122 * System.out.println(data)
123 * </pre></blockquote>
124 * <p>
125 * See the <code>println</code> methods in class <code>PrintStream</code>.
126 *
127 * @see java.io.PrintStream#println()
128 * @see java.io.PrintStream#println(boolean)
129 * @see java.io.PrintStream#println(char)
130 * @see java.io.PrintStream#println(char[])
131 * @see java.io.PrintStream#println(double)
132 * @see java.io.PrintStream#println(float)
133 * @see java.io.PrintStream#println(int)
134 * @see java.io.PrintStream#println(long)
135 * @see java.io.PrintStream#println(java.lang.Object)
136 * @see java.io.PrintStream#println(java.lang.String)
137 */
138 public static final PrintStream out = null;
139
140 /**
141 * The "standard" error output stream. This stream is already
142 * open and ready to accept output data.
143 * <p>
144 * Typically this stream corresponds to display output or another
145 * output destination specified by the host environment or user. By
146 * convention, this output stream is used to display error messages
147 * or other information that should come to the immediate attention
148 * of a user even if the principal output stream, the value of the
149 * variable <code>out</code>, has been redirected to a file or other
150 * destination that is typically not continuously monitored.
151 */
152 public static final PrintStream err = null;
153
154 /* The security manager for the system.
155 */
156 private static volatile SecurityManager security;
157
158 /**
159 * Reassigns the "standard" input stream.
160 *
161 * <p>First, if there is a security manager, its <code>checkPermission</code>
162 * method is called with a <code>RuntimePermission("setIO")</code> permission
163 * to see if it's ok to reassign the "standard" input stream.
164 *
165 * @param in the new standard input stream.
166 *
167 * @throws SecurityException
168 * if a security manager exists and its
169 * <code>checkPermission</code> method doesn't allow
170 * reassigning of the standard input stream.
171 *
172 * @see SecurityManager#checkPermission
173 * @see java.lang.RuntimePermission
174 *
175 * @since 1.1
176 */
177 public static void setIn(InputStream in) {
178 checkIO();
179 setIn0(in);
180 }
181
182 /**
183 * Reassigns the "standard" output stream.
184 *
185 * <p>First, if there is a security manager, its <code>checkPermission</code>
186 * method is called with a <code>RuntimePermission("setIO")</code> permission
187 * to see if it's ok to reassign the "standard" output stream.
188 *
189 * @param out the new standard output stream
190 *
191 * @throws SecurityException
192 * if a security manager exists and its
193 * <code>checkPermission</code> method doesn't allow
194 * reassigning of the standard output stream.
195 *
196 * @see SecurityManager#checkPermission
197 * @see java.lang.RuntimePermission
198 *
199 * @since 1.1
200 */
201 public static void setOut(PrintStream out) {
202 checkIO();
203 setOut0(out);
204 }
205
206 /**
207 * Reassigns the "standard" error output stream.
208 *
209 * <p>First, if there is a security manager, its <code>checkPermission</code>
210 * method is called with a <code>RuntimePermission("setIO")</code> permission
211 * to see if it's ok to reassign the "standard" error output stream.
212 *
213 * @param err the new standard error output stream.
214 *
215 * @throws SecurityException
216 * if a security manager exists and its
217 * <code>checkPermission</code> method doesn't allow
218 * reassigning of the standard error output stream.
219 *
220 * @see SecurityManager#checkPermission
221 * @see java.lang.RuntimePermission
222 *
223 * @since 1.1
224 */
225 public static void setErr(PrintStream err) {
226 checkIO();
227 setErr0(err);
228 }
229
230 private static volatile Console cons;
231 /**
232 * Returns the unique {@link java.io.Console Console} object associated
233 * with the current Java virtual machine, if any.
234 *
235 * @return The system console, if any, otherwise {@code null}.
236 *
237 * @since 1.6
238 */
239 public static Console console() {
240 Console c = cons;
241 if (c == null) {
242 synchronized (System.class) {
243 cons = c = SharedSecrets.getJavaIOAccess().console();
244 }
245 }
246 return c;
247 }
248
249 /**
250 * Returns the channel inherited from the entity that created this
251 * Java virtual machine.
252 *
253 * <p> This method returns the channel obtained by invoking the
254 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
255 * inheritedChannel} method of the system-wide default
256 * {@link java.nio.channels.spi.SelectorProvider} object. </p>
257 *
258 * <p> In addition to the network-oriented channels described in
259 * {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
260 * inheritedChannel}, this method may return other kinds of
261 * channels in the future.
262 *
263 * @return The inherited channel, if any, otherwise {@code null}.
264 *
265 * @throws IOException
266 * If an I/O error occurs
267 *
268 * @throws SecurityException
269 * If a security manager is present and it does not
270 * permit access to the channel.
271 *
272 * @since 1.5
273 */
274 public static Channel inheritedChannel() throws IOException {
275 return SelectorProvider.provider().inheritedChannel();
276 }
277
278 private static void checkIO() {
279 SecurityManager sm = getSecurityManager();
280 if (sm != null) {
281 sm.checkPermission(new RuntimePermission("setIO"));
282 }
283 }
284
285 private static native void setIn0(InputStream in);
286 private static native void setOut0(PrintStream out);
287 private static native void setErr0(PrintStream err);
288
289 /**
290 * Sets the System security.
291 *
292 * <p> If there is a security manager already installed, this method first
293 * calls the security manager's <code>checkPermission</code> method
294 * with a <code>RuntimePermission("setSecurityManager")</code>
295 * permission to ensure it's ok to replace the existing
296 * security manager.
297 * This may result in throwing a <code>SecurityException</code>.
298 *
299 * <p> Otherwise, the argument is established as the current
300 * security manager. If the argument is <code>null</code> and no
301 * security manager has been established, then no action is taken and
302 * the method simply returns.
303 *
304 * @param s the security manager.
305 * @exception SecurityException if the security manager has already
306 * been set and its <code>checkPermission</code> method
307 * doesn't allow it to be replaced.
308 * @see #getSecurityManager
309 * @see SecurityManager#checkPermission
310 * @see java.lang.RuntimePermission
311 */
312 public static
313 void setSecurityManager(final SecurityManager s) {
314 try {
315 s.checkPackageAccess("java.lang");
316 } catch (Exception e) {
317 // no-op
318 }
319 setSecurityManager0(s);
320 }
321
322 private static synchronized
323 void setSecurityManager0(final SecurityManager s) {
324 SecurityManager sm = getSecurityManager();
325 if (sm != null) {
326 // ask the currently installed security manager if we
327 // can replace it.
328 sm.checkPermission(new RuntimePermission
329 ("setSecurityManager"));
330 }
331
332 if ((s != null) && (s.getClass().getClassLoader() != null)) {
333 // New security manager class is not on bootstrap classpath.
334 // Cause policy to get initialized before we install the new
335 // security manager, in order to prevent infinite loops when
336 // trying to initialize the policy (which usually involves
337 // accessing some security and/or system properties, which in turn
338 // calls the installed security manager's checkPermission method
339 // which will loop infinitely if there is a non-system class
340 // (in this case: the new security manager class) on the stack).
341 AccessController.doPrivileged(new PrivilegedAction<>() {
342 public Object run() {
343 s.getClass().getProtectionDomain().implies
344 (SecurityConstants.ALL_PERMISSION);
345 return null;
346 }
347 });
348 }
349
350 security = s;
351 }
352
353 /**
354 * Gets the system security interface.
355 *
356 * @return if a security manager has already been established for the
357 * current application, then that security manager is returned;
358 * otherwise, <code>null</code> is returned.
359 * @see #setSecurityManager
360 */
361 public static SecurityManager getSecurityManager() {
362 return security;
363 }
364
365 /**
366 * Returns the current time in milliseconds. Note that
367 * while the unit of time of the return value is a millisecond,
368 * the granularity of the value depends on the underlying
369 * operating system and may be larger. For example, many
370 * operating systems measure time in units of tens of
371 * milliseconds.
372 *
373 * <p> See the description of the class <code>Date</code> for
374 * a discussion of slight discrepancies that may arise between
375 * "computer time" and coordinated universal time (UTC).
376 *
377 * @return the difference, measured in milliseconds, between
378 * the current time and midnight, January 1, 1970 UTC.
379 * @see java.util.Date
380 */
381 @HotSpotIntrinsicCandidate
382 public static native long currentTimeMillis();
383
384 /**
385 * Returns the current value of the running Java Virtual Machine's
386 * high-resolution time source, in nanoseconds.
387 *
388 * <p>This method can only be used to measure elapsed time and is
389 * not related to any other notion of system or wall-clock time.
390 * The value returned represents nanoseconds since some fixed but
391 * arbitrary <i>origin</i> time (perhaps in the future, so values
392 * may be negative). The same origin is used by all invocations of
393 * this method in an instance of a Java virtual machine; other
394 * virtual machine instances are likely to use a different origin.
395 *
396 * <p>This method provides nanosecond precision, but not necessarily
397 * nanosecond resolution (that is, how frequently the value changes)
398 * - no guarantees are made except that the resolution is at least as
399 * good as that of {@link #currentTimeMillis()}.
400 *
401 * <p>Differences in successive calls that span greater than
402 * approximately 292 years (2<sup>63</sup> nanoseconds) will not
403 * correctly compute elapsed time due to numerical overflow.
404 *
405 * <p>The values returned by this method become meaningful only when
406 * the difference between two such values, obtained within the same
407 * instance of a Java virtual machine, is computed.
408 *
409 * <p>For example, to measure how long some code takes to execute:
410 * <pre> {@code
411 * long startTime = System.nanoTime();
412 * // ... the code being measured ...
413 * long elapsedNanos = System.nanoTime() - startTime;}</pre>
414 *
415 * <p>To compare elapsed time against a timeout, use <pre> {@code
416 * if (System.nanoTime() - startTime >= timeoutNanos) ...}</pre>
417 * instead of <pre> {@code
418 * if (System.nanoTime() >= startTime + timeoutNanos) ...}</pre>
419 * because of the possibility of numerical overflow.
420 *
421 * @return the current value of the running Java Virtual Machine's
422 * high-resolution time source, in nanoseconds
423 * @since 1.5
424 */
425 @HotSpotIntrinsicCandidate
426 public static native long nanoTime();
427
428 /**
429 * Copies an array from the specified source array, beginning at the
430 * specified position, to the specified position of the destination array.
431 * A subsequence of array components are copied from the source
432 * array referenced by <code>src</code> to the destination array
433 * referenced by <code>dest</code>. The number of components copied is
434 * equal to the <code>length</code> argument. The components at
435 * positions <code>srcPos</code> through
436 * <code>srcPos+length-1</code> in the source array are copied into
437 * positions <code>destPos</code> through
438 * <code>destPos+length-1</code>, respectively, of the destination
439 * array.
440 * <p>
441 * If the <code>src</code> and <code>dest</code> arguments refer to the
442 * same array object, then the copying is performed as if the
443 * components at positions <code>srcPos</code> through
444 * <code>srcPos+length-1</code> were first copied to a temporary
445 * array with <code>length</code> components and then the contents of
446 * the temporary array were copied into positions
447 * <code>destPos</code> through <code>destPos+length-1</code> of the
448 * destination array.
449 * <p>
450 * If <code>dest</code> is <code>null</code>, then a
451 * <code>NullPointerException</code> is thrown.
452 * <p>
453 * If <code>src</code> is <code>null</code>, then a
454 * <code>NullPointerException</code> is thrown and the destination
455 * array is not modified.
456 * <p>
457 * Otherwise, if any of the following is true, an
458 * <code>ArrayStoreException</code> is thrown and the destination is
459 * not modified:
460 * <ul>
461 * <li>The <code>src</code> argument refers to an object that is not an
462 * array.
463 * <li>The <code>dest</code> argument refers to an object that is not an
464 * array.
465 * <li>The <code>src</code> argument and <code>dest</code> argument refer
466 * to arrays whose component types are different primitive types.
467 * <li>The <code>src</code> argument refers to an array with a primitive
468 * component type and the <code>dest</code> argument refers to an array
469 * with a reference component type.
470 * <li>The <code>src</code> argument refers to an array with a reference
471 * component type and the <code>dest</code> argument refers to an array
472 * with a primitive component type.
473 * </ul>
474 * <p>
475 * Otherwise, if any of the following is true, an
476 * <code>IndexOutOfBoundsException</code> is
477 * thrown and the destination is not modified:
478 * <ul>
479 * <li>The <code>srcPos</code> argument is negative.
480 * <li>The <code>destPos</code> argument is negative.
481 * <li>The <code>length</code> argument is negative.
482 * <li><code>srcPos+length</code> is greater than
483 * <code>src.length</code>, the length of the source array.
484 * <li><code>destPos+length</code> is greater than
485 * <code>dest.length</code>, the length of the destination array.
486 * </ul>
487 * <p>
488 * Otherwise, if any actual component of the source array from
489 * position <code>srcPos</code> through
490 * <code>srcPos+length-1</code> cannot be converted to the component
491 * type of the destination array by assignment conversion, an
492 * <code>ArrayStoreException</code> is thrown. In this case, let
493 * <b><i>k</i></b> be the smallest nonnegative integer less than
494 * length such that <code>src[srcPos+</code><i>k</i><code>]</code>
495 * cannot be converted to the component type of the destination
496 * array; when the exception is thrown, source array components from
497 * positions <code>srcPos</code> through
498 * <code>srcPos+</code><i>k</i><code>-1</code>
499 * will already have been copied to destination array positions
500 * <code>destPos</code> through
501 * <code>destPos+</code><i>k</I><code>-1</code> and no other
502 * positions of the destination array will have been modified.
503 * (Because of the restrictions already itemized, this
504 * paragraph effectively applies only to the situation where both
505 * arrays have component types that are reference types.)
506 *
507 * @param src the source array.
508 * @param srcPos starting position in the source array.
509 * @param dest the destination array.
510 * @param destPos starting position in the destination data.
511 * @param length the number of array elements to be copied.
512 * @exception IndexOutOfBoundsException if copying would cause
513 * access of data outside array bounds.
514 * @exception ArrayStoreException if an element in the <code>src</code>
515 * array could not be stored into the <code>dest</code> array
516 * because of a type mismatch.
517 * @exception NullPointerException if either <code>src</code> or
518 * <code>dest</code> is <code>null</code>.
519 */
520 @HotSpotIntrinsicCandidate
521 public static native void arraycopy(Object src, int srcPos,
522 Object dest, int destPos,
523 int length);
524
525 /**
526 * Returns the same hash code for the given object as
527 * would be returned by the default method hashCode(),
528 * whether or not the given object's class overrides
529 * hashCode().
530 * The hash code for the null reference is zero.
531 *
532 * @param x object for which the hashCode is to be calculated
533 * @return the hashCode
534 * @since 1.1
535 */
536 @HotSpotIntrinsicCandidate
537 public static native int identityHashCode(Object x);
538
539 /**
540 * System properties. The following properties are guaranteed to be defined:
541 * <dl>
542 * <dt>java.version <dd>Java version number
543 * <dt>java.vendor <dd>Java vendor specific string
544 * <dt>java.vendor.url <dd>Java vendor URL
545 * <dt>java.home <dd>Java installation directory
546 * <dt>java.class.version <dd>Java class version number
547 * <dt>java.class.path <dd>Java classpath
548 * <dt>os.name <dd>Operating System Name
549 * <dt>os.arch <dd>Operating System Architecture
550 * <dt>os.version <dd>Operating System Version
551 * <dt>file.separator <dd>File separator ("/" on Unix)
552 * <dt>path.separator <dd>Path separator (":" on Unix)
553 * <dt>line.separator <dd>Line separator ("\n" on Unix)
554 * <dt>user.name <dd>User account name
555 * <dt>user.home <dd>User home directory
556 * <dt>user.dir <dd>User's current working directory
557 * </dl>
558 */
559
560 private static Properties props;
561 private static native Properties initProperties(Properties props);
562
563 /**
564 * Determines the current system properties.
565 * <p>
566 * First, if there is a security manager, its
567 * <code>checkPropertiesAccess</code> method is called with no
568 * arguments. This may result in a security exception.
569 * <p>
570 * The current set of system properties for use by the
571 * {@link #getProperty(String)} method is returned as a
572 * <code>Properties</code> object. If there is no current set of
573 * system properties, a set of system properties is first created and
574 * initialized. This set of system properties always includes values
575 * for the following keys:
576 * <table summary="Shows property keys and associated values">
577 * <tr><th>Key</th>
578 * <th>Description of Associated Value</th></tr>
579 * <tr><td><code>java.version</code></td>
580 * <td>Java Runtime Environment version</td></tr>
581 * <tr><td><code>java.vendor</code></td>
582 * <td>Java Runtime Environment vendor</td></tr>
583 * <tr><td><code>java.vendor.url</code></td>
584 * <td>Java vendor URL</td></tr>
585 * <tr><td><code>java.home</code></td>
586 * <td>Java installation directory</td></tr>
587 * <tr><td><code>java.vm.specification.version</code></td>
588 * <td>Java Virtual Machine specification version</td></tr>
589 * <tr><td><code>java.vm.specification.vendor</code></td>
590 * <td>Java Virtual Machine specification vendor</td></tr>
591 * <tr><td><code>java.vm.specification.name</code></td>
592 * <td>Java Virtual Machine specification name</td></tr>
593 * <tr><td><code>java.vm.version</code></td>
594 * <td>Java Virtual Machine implementation version</td></tr>
595 * <tr><td><code>java.vm.vendor</code></td>
596 * <td>Java Virtual Machine implementation vendor</td></tr>
597 * <tr><td><code>java.vm.name</code></td>
598 * <td>Java Virtual Machine implementation name</td></tr>
599 * <tr><td><code>java.specification.version</code></td>
600 * <td>Java Runtime Environment specification version</td></tr>
601 * <tr><td><code>java.specification.vendor</code></td>
602 * <td>Java Runtime Environment specification vendor</td></tr>
603 * <tr><td><code>java.specification.name</code></td>
604 * <td>Java Runtime Environment specification name</td></tr>
605 * <tr><td><code>java.class.version</code></td>
606 * <td>Java class format version number</td></tr>
607 * <tr><td><code>java.class.path</code></td>
608 * <td>Java class path</td></tr>
609 * <tr><td><code>java.library.path</code></td>
610 * <td>List of paths to search when loading libraries</td></tr>
611 * <tr><td><code>java.io.tmpdir</code></td>
612 * <td>Default temp file path</td></tr>
613 * <tr><td><code>java.compiler</code></td>
614 * <td>Name of JIT compiler to use</td></tr>
615 * <tr><td><code>os.name</code></td>
616 * <td>Operating system name</td></tr>
617 * <tr><td><code>os.arch</code></td>
618 * <td>Operating system architecture</td></tr>
619 * <tr><td><code>os.version</code></td>
620 * <td>Operating system version</td></tr>
621 * <tr><td><code>file.separator</code></td>
622 * <td>File separator ("/" on UNIX)</td></tr>
623 * <tr><td><code>path.separator</code></td>
624 * <td>Path separator (":" on UNIX)</td></tr>
625 * <tr><td><code>line.separator</code></td>
626 * <td>Line separator ("\n" on UNIX)</td></tr>
627 * <tr><td><code>user.name</code></td>
628 * <td>User's account name</td></tr>
629 * <tr><td><code>user.home</code></td>
630 * <td>User's home directory</td></tr>
631 * <tr><td><code>user.dir</code></td>
632 * <td>User's current working directory</td></tr>
633 * </table>
634 * <p>
635 * Multiple paths in a system property value are separated by the path
636 * separator character of the platform.
637 * <p>
638 * Note that even if the security manager does not permit the
639 * <code>getProperties</code> operation, it may choose to permit the
640 * {@link #getProperty(String)} operation.
641 *
642 * @implNote In addition to the standard system properties, the {@code
643 * java} launcher may create the Java Virtual Machine with system
644 * properties that have the following keys:
645 * <table summary="Shows property keys and associated values">
646 * <tr><th>Key</th>
647 * <th>Description of Associated Value</th></tr>
648 * <tr><td>{@code jdk.module.path}</td>
649 * <td>Application module path</td></tr>
650 * <tr><td>{@code jdk.upgrade.module.path}</td>
651 * <td>The upgrade module path</td></tr>
652 * <tr><td>{@code jdk.module.main}</td>
653 * <td>The module name of the initial/main module</td></tr>
654 * <tr><td>{@code jdk.module.main.class}</td>
655 * <td>The main class name of the initial module</td></tr>
656 * </table>
657 * These properties may also be set by custom launchers that use the JNI
658 * invocation API to create the Java Virtual Machine.
659 *
660 * @return the system properties
661 * @exception SecurityException if a security manager exists and its
662 * <code>checkPropertiesAccess</code> method doesn't allow access
663 * to the system properties.
664 * @see #setProperties
665 * @see java.lang.SecurityException
666 * @see java.lang.SecurityManager#checkPropertiesAccess()
667 * @see java.util.Properties
668 */
669 public static Properties getProperties() {
670 SecurityManager sm = getSecurityManager();
671 if (sm != null) {
672 sm.checkPropertiesAccess();
673 }
674
675 return props;
676 }
677
678 /**
679 * Returns the system-dependent line separator string. It always
680 * returns the same value - the initial value of the {@linkplain
681 * #getProperty(String) system property} {@code line.separator}.
682 *
683 * <p>On UNIX systems, it returns {@code "\n"}; on Microsoft
684 * Windows systems it returns {@code "\r\n"}.
685 *
686 * @return the system-dependent line separator string
687 * @since 1.7
688 */
689 public static String lineSeparator() {
690 return lineSeparator;
691 }
692
693 private static String lineSeparator;
694
695 /**
696 * Sets the system properties to the <code>Properties</code>
697 * argument.
698 * <p>
699 * First, if there is a security manager, its
700 * <code>checkPropertiesAccess</code> method is called with no
701 * arguments. This may result in a security exception.
702 * <p>
703 * The argument becomes the current set of system properties for use
704 * by the {@link #getProperty(String)} method. If the argument is
705 * <code>null</code>, then the current set of system properties is
706 * forgotten.
707 *
708 * @param props the new system properties.
709 * @exception SecurityException if a security manager exists and its
710 * <code>checkPropertiesAccess</code> method doesn't allow access
711 * to the system properties.
712 * @see #getProperties
713 * @see java.util.Properties
714 * @see java.lang.SecurityException
715 * @see java.lang.SecurityManager#checkPropertiesAccess()
716 */
717 public static void setProperties(Properties props) {
718 SecurityManager sm = getSecurityManager();
719 if (sm != null) {
720 sm.checkPropertiesAccess();
721 }
722 if (props == null) {
723 props = new Properties();
724 initProperties(props);
725 }
726 System.props = props;
727 }
728
729 /**
730 * Gets the system property indicated by the specified key.
731 * <p>
732 * First, if there is a security manager, its
733 * <code>checkPropertyAccess</code> method is called with the key as
734 * its argument. This may result in a SecurityException.
735 * <p>
736 * If there is no current set of system properties, a set of system
737 * properties is first created and initialized in the same manner as
738 * for the <code>getProperties</code> method.
739 *
740 * @param key the name of the system property.
741 * @return the string value of the system property,
742 * or <code>null</code> if there is no property with that key.
743 *
744 * @exception SecurityException if a security manager exists and its
745 * <code>checkPropertyAccess</code> method doesn't allow
746 * access to the specified system property.
747 * @exception NullPointerException if <code>key</code> is
748 * <code>null</code>.
749 * @exception IllegalArgumentException if <code>key</code> is empty.
750 * @see #setProperty
751 * @see java.lang.SecurityException
752 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
753 * @see java.lang.System#getProperties()
754 */
755 public static String getProperty(String key) {
756 checkKey(key);
757 SecurityManager sm = getSecurityManager();
758 if (sm != null) {
759 sm.checkPropertyAccess(key);
760 }
761
762 return props.getProperty(key);
763 }
764
765 /**
766 * Gets the system property indicated by the specified key.
767 * <p>
768 * First, if there is a security manager, its
769 * <code>checkPropertyAccess</code> method is called with the
770 * <code>key</code> as its argument.
771 * <p>
772 * If there is no current set of system properties, a set of system
773 * properties is first created and initialized in the same manner as
774 * for the <code>getProperties</code> method.
775 *
776 * @param key the name of the system property.
777 * @param def a default value.
778 * @return the string value of the system property,
779 * or the default value if there is no property with that key.
780 *
781 * @exception SecurityException if a security manager exists and its
782 * <code>checkPropertyAccess</code> method doesn't allow
783 * access to the specified system property.
784 * @exception NullPointerException if <code>key</code> is
785 * <code>null</code>.
786 * @exception IllegalArgumentException if <code>key</code> is empty.
787 * @see #setProperty
788 * @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
789 * @see java.lang.System#getProperties()
790 */
791 public static String getProperty(String key, String def) {
792 checkKey(key);
793 SecurityManager sm = getSecurityManager();
794 if (sm != null) {
795 sm.checkPropertyAccess(key);
796 }
797
798 return props.getProperty(key, def);
799 }
800
801 /**
802 * Sets the system property indicated by the specified key.
803 * <p>
804 * First, if a security manager exists, its
805 * <code>SecurityManager.checkPermission</code> method
806 * is called with a <code>PropertyPermission(key, "write")</code>
807 * permission. This may result in a SecurityException being thrown.
808 * If no exception is thrown, the specified property is set to the given
809 * value.
810 *
811 * @param key the name of the system property.
812 * @param value the value of the system property.
813 * @return the previous value of the system property,
814 * or <code>null</code> if it did not have one.
815 *
816 * @exception SecurityException if a security manager exists and its
817 * <code>checkPermission</code> method doesn't allow
818 * setting of the specified property.
819 * @exception NullPointerException if <code>key</code> or
820 * <code>value</code> is <code>null</code>.
821 * @exception IllegalArgumentException if <code>key</code> is empty.
822 * @see #getProperty
823 * @see java.lang.System#getProperty(java.lang.String)
824 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
825 * @see java.util.PropertyPermission
826 * @see SecurityManager#checkPermission
827 * @since 1.2
828 */
829 public static String setProperty(String key, String value) {
830 checkKey(key);
831 SecurityManager sm = getSecurityManager();
832 if (sm != null) {
833 sm.checkPermission(new PropertyPermission(key,
834 SecurityConstants.PROPERTY_WRITE_ACTION));
835 }
836
837 return (String) props.setProperty(key, value);
838 }
839
840 /**
841 * Removes the system property indicated by the specified key.
842 * <p>
843 * First, if a security manager exists, its
844 * <code>SecurityManager.checkPermission</code> method
845 * is called with a <code>PropertyPermission(key, "write")</code>
846 * permission. This may result in a SecurityException being thrown.
847 * If no exception is thrown, the specified property is removed.
848 *
849 * @param key the name of the system property to be removed.
850 * @return the previous string value of the system property,
851 * or <code>null</code> if there was no property with that key.
852 *
853 * @exception SecurityException if a security manager exists and its
854 * <code>checkPropertyAccess</code> method doesn't allow
855 * access to the specified system property.
856 * @exception NullPointerException if <code>key</code> is
857 * <code>null</code>.
858 * @exception IllegalArgumentException if <code>key</code> is empty.
859 * @see #getProperty
860 * @see #setProperty
861 * @see java.util.Properties
862 * @see java.lang.SecurityException
863 * @see java.lang.SecurityManager#checkPropertiesAccess()
864 * @since 1.5
865 */
866 public static String clearProperty(String key) {
867 checkKey(key);
868 SecurityManager sm = getSecurityManager();
869 if (sm != null) {
870 sm.checkPermission(new PropertyPermission(key, "write"));
871 }
872
873 return (String) props.remove(key);
874 }
875
876 private static void checkKey(String key) {
877 if (key == null) {
878 throw new NullPointerException("key can't be null");
879 }
880 if (key.equals("")) {
881 throw new IllegalArgumentException("key can't be empty");
882 }
883 }
884
885 /**
886 * Gets the value of the specified environment variable. An
887 * environment variable is a system-dependent external named
888 * value.
889 *
890 * <p>If a security manager exists, its
891 * {@link SecurityManager#checkPermission checkPermission}
892 * method is called with a
893 * <code>{@link RuntimePermission}("getenv."+name)</code>
894 * permission. This may result in a {@link SecurityException}
895 * being thrown. If no exception is thrown the value of the
896 * variable <code>name</code> is returned.
897 *
898 * <p><a name="EnvironmentVSSystemProperties"><i>System
899 * properties</i> and <i>environment variables</i></a> are both
900 * conceptually mappings between names and values. Both
901 * mechanisms can be used to pass user-defined information to a
902 * Java process. Environment variables have a more global effect,
903 * because they are visible to all descendants of the process
904 * which defines them, not just the immediate Java subprocess.
905 * They can have subtly different semantics, such as case
906 * insensitivity, on different operating systems. For these
907 * reasons, environment variables are more likely to have
908 * unintended side effects. It is best to use system properties
909 * where possible. Environment variables should be used when a
910 * global effect is desired, or when an external system interface
911 * requires an environment variable (such as <code>PATH</code>).
912 *
913 * <p>On UNIX systems the alphabetic case of <code>name</code> is
914 * typically significant, while on Microsoft Windows systems it is
915 * typically not. For example, the expression
916 * <code>System.getenv("FOO").equals(System.getenv("foo"))</code>
917 * is likely to be true on Microsoft Windows.
918 *
919 * @param name the name of the environment variable
920 * @return the string value of the variable, or <code>null</code>
921 * if the variable is not defined in the system environment
922 * @throws NullPointerException if <code>name</code> is <code>null</code>
923 * @throws SecurityException
924 * if a security manager exists and its
925 * {@link SecurityManager#checkPermission checkPermission}
926 * method doesn't allow access to the environment variable
927 * <code>name</code>
928 * @see #getenv()
929 * @see ProcessBuilder#environment()
930 */
931 public static String getenv(String name) {
932 SecurityManager sm = getSecurityManager();
933 if (sm != null) {
934 sm.checkPermission(new RuntimePermission("getenv."+name));
935 }
936
937 return ProcessEnvironment.getenv(name);
938 }
939
940
941 /**
942 * Returns an unmodifiable string map view of the current system environment.
943 * The environment is a system-dependent mapping from names to
944 * values which is passed from parent to child processes.
945 *
946 * <p>If the system does not support environment variables, an
947 * empty map is returned.
948 *
949 * <p>The returned map will never contain null keys or values.
950 * Attempting to query the presence of a null key or value will
951 * throw a {@link NullPointerException}. Attempting to query
952 * the presence of a key or value which is not of type
953 * {@link String} will throw a {@link ClassCastException}.
954 *
955 * <p>The returned map and its collection views may not obey the
956 * general contract of the {@link Object#equals} and
957 * {@link Object#hashCode} methods.
958 *
959 * <p>The returned map is typically case-sensitive on all platforms.
960 *
961 * <p>If a security manager exists, its
962 * {@link SecurityManager#checkPermission checkPermission}
963 * method is called with a
964 * <code>{@link RuntimePermission}("getenv.*")</code>
965 * permission. This may result in a {@link SecurityException} being
966 * thrown.
967 *
968 * <p>When passing information to a Java subprocess,
969 * <a href=#EnvironmentVSSystemProperties>system properties</a>
970 * are generally preferred over environment variables.
971 *
972 * @return the environment as a map of variable names to values
973 * @throws SecurityException
974 * if a security manager exists and its
975 * {@link SecurityManager#checkPermission checkPermission}
976 * method doesn't allow access to the process environment
977 * @see #getenv(String)
978 * @see ProcessBuilder#environment()
979 * @since 1.5
980 */
981 public static java.util.Map<String,String> getenv() {
982 SecurityManager sm = getSecurityManager();
983 if (sm != null) {
984 sm.checkPermission(new RuntimePermission("getenv.*"));
985 }
986
987 return ProcessEnvironment.getenv();
988 }
989
990 /**
991 * {@code System.Logger} instances log messages that will be
992 * routed to the underlying logging framework the {@link System.LoggerFinder
993 * LoggerFinder} uses.
994 * <p>
995 * {@code System.Logger} instances are typically obtained from
996 * the {@link java.lang.System System} class, by calling
997 * {@link java.lang.System#getLogger(java.lang.String) System.getLogger(loggerName)}
998 * or {@link java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
999 * System.getLogger(loggerName, bundle)}.
1000 *
1001 * @see java.lang.System#getLogger(java.lang.String)
1002 * @see java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
1003 * @see java.lang.System.LoggerFinder
1004 *
1005 * @since 9
1006 *
1007 */
1008 public interface Logger {
1009
1010 /**
1011 * System {@linkplain Logger loggers} levels.
1012 * <p>
1013 * A level has a {@linkplain #getName() name} and {@linkplain
1014 * #getSeverity() severity}.
1015 * Level values are {@link #ALL}, {@link #TRACE}, {@link #DEBUG},
1016 * {@link #INFO}, {@link #WARNING}, {@link #ERROR}, {@link #OFF},
1017 * by order of increasing severity.
1018 * <br>
1019 * {@link #ALL} and {@link #OFF}
1020 * are simple markers with severities mapped respectively to
1021 * {@link java.lang.Integer#MIN_VALUE Integer.MIN_VALUE} and
1022 * {@link java.lang.Integer#MAX_VALUE Integer.MAX_VALUE}.
1023 * <p>
1024 * <b>Severity values and Mapping to {@code java.util.logging.Level}.</b>
1025 * <p>
1026 * {@linkplain System.Logger.Level System logger levels} are mapped to
1027 * {@linkplain java.util.logging.Level java.util.logging levels}
1028 * of corresponding severity.
1029 * <br>The mapping is as follows:
1030 * <br><br>
1031 * <table border="1">
1032 * <caption>System.Logger Severity Level Mapping</caption>
1033 * <tr><td><b>System.Logger Levels</b></td>
1034 * <td>{@link Logger.Level#ALL ALL}</td>
1035 * <td>{@link Logger.Level#TRACE TRACE}</td>
1036 * <td>{@link Logger.Level#DEBUG DEBUG}</td>
1037 * <td>{@link Logger.Level#INFO INFO}</td>
1038 * <td>{@link Logger.Level#WARNING WARNING}</td>
1039 * <td>{@link Logger.Level#ERROR ERROR}</td>
1040 * <td>{@link Logger.Level#OFF OFF}</td>
1041 * </tr>
1042 * <tr><td><b>java.util.logging Levels</b></td>
1043 * <td>{@link java.util.logging.Level#ALL ALL}</td>
1044 * <td>{@link java.util.logging.Level#FINER FINER}</td>
1045 * <td>{@link java.util.logging.Level#FINE FINE}</td>
1046 * <td>{@link java.util.logging.Level#INFO INFO}</td>
1047 * <td>{@link java.util.logging.Level#WARNING WARNING}</td>
1048 * <td>{@link java.util.logging.Level#SEVERE SEVERE}</td>
1049 * <td>{@link java.util.logging.Level#OFF OFF}</td>
1050 * </tr>
1051 * </table>
1052 *
1053 * @since 9
1054 *
1055 * @see java.lang.System.LoggerFinder
1056 * @see java.lang.System.Logger
1057 */
1058 public enum Level {
1059
1060 // for convenience, we're reusing java.util.logging.Level int values
1061 // the mapping logic in sun.util.logging.PlatformLogger depends
1062 // on this.
1063 /**
1064 * A marker to indicate that all levels are enabled.
1065 * This level {@linkplain #getSeverity() severity} is
1066 * {@link Integer#MIN_VALUE}.
1067 */
1068 ALL(Integer.MIN_VALUE), // typically mapped to/from j.u.l.Level.ALL
1069 /**
1070 * {@code TRACE} level: usually used to log diagnostic information.
1071 * This level {@linkplain #getSeverity() severity} is
1072 * {@code 400}.
1073 */
1074 TRACE(400), // typically mapped to/from j.u.l.Level.FINER
1075 /**
1076 * {@code DEBUG} level: usually used to log debug information traces.
1077 * This level {@linkplain #getSeverity() severity} is
1078 * {@code 500}.
1079 */
1080 DEBUG(500), // typically mapped to/from j.u.l.Level.FINEST/FINE/CONFIG
1081 /**
1082 * {@code INFO} level: usually used to log information messages.
1083 * This level {@linkplain #getSeverity() severity} is
1084 * {@code 800}.
1085 */
1086 INFO(800), // typically mapped to/from j.u.l.Level.INFO
1087 /**
1088 * {@code WARNING} level: usually used to log warning messages.
1089 * This level {@linkplain #getSeverity() severity} is
1090 * {@code 900}.
1091 */
1092 WARNING(900), // typically mapped to/from j.u.l.Level.WARNING
1093 /**
1094 * {@code ERROR} level: usually used to log error messages.
1095 * This level {@linkplain #getSeverity() severity} is
1096 * {@code 1000}.
1097 */
1098 ERROR(1000), // typically mapped to/from j.u.l.Level.SEVERE
1099 /**
1100 * A marker to indicate that all levels are disabled.
1101 * This level {@linkplain #getSeverity() severity} is
1102 * {@link Integer#MAX_VALUE}.
1103 */
1104 OFF(Integer.MAX_VALUE); // typically mapped to/from j.u.l.Level.OFF
1105
1106 private final int severity;
1107
1108 private Level(int severity) {
1109 this.severity = severity;
1110 }
1111
1112 /**
1113 * Returns the name of this level.
1114 * @return this level {@linkplain #name()}.
1115 */
1116 public final String getName() {
1117 return name();
1118 }
1119
1120 /**
1121 * Returns the severity of this level.
1122 * A higher severity means a more severe condition.
1123 * @return this level severity.
1124 */
1125 public final int getSeverity() {
1126 return severity;
1127 }
1128 }
1129
1130 /**
1131 * Returns the name of this logger.
1132 *
1133 * @return the logger name.
1134 */
1135 public String getName();
1136
1137 /**
1138 * Checks if a message of the given level would be logged by
1139 * this logger.
1140 *
1141 * @param level the log message level.
1142 * @return {@code true} if the given log message level is currently
1143 * being logged.
1144 *
1145 * @throws NullPointerException if {@code level} is {@code null}.
1146 */
1147 public boolean isLoggable(Level level);
1148
1149 /**
1150 * Logs a message.
1151 *
1152 * @implSpec The default implementation for this method calls
1153 * {@code this.log(level, (ResourceBundle)null, msg, (Object[])null);}
1154 *
1155 * @param level the log message level.
1156 * @param msg the string message (or a key in the message catalog, if
1157 * this logger is a {@link
1158 * LoggerFinder#getLocalizedLogger(java.lang.String,
1159 * java.util.ResourceBundle, java.lang.reflect.Module) localized logger});
1160 * can be {@code null}.
1161 *
1162 * @throws NullPointerException if {@code level} is {@code null}.
1163 */
1164 public default void log(Level level, String msg) {
1165 log(level, (ResourceBundle) null, msg, (Object[]) null);
1166 }
1167
1168 /**
1169 * Logs a lazily supplied message.
1170 * <p>
1171 * If the logger is currently enabled for the given log message level
1172 * then a message is logged that is the result produced by the
1173 * given supplier function. Otherwise, the supplier is not operated on.
1174 *
1175 * @implSpec When logging is enabled for the given level, the default
1176 * implementation for this method calls
1177 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), (Object[])null);}
1178 *
1179 * @param level the log message level.
1180 * @param msgSupplier a supplier function that produces a message.
1181 *
1182 * @throws NullPointerException if {@code level} is {@code null},
1183 * or {@code msgSupplier} is {@code null}.
1184 */
1185 public default void log(Level level, Supplier<String> msgSupplier) {
1186 Objects.requireNonNull(msgSupplier);
1187 if (isLoggable(Objects.requireNonNull(level))) {
1188 log(level, (ResourceBundle) null, msgSupplier.get(), (Object[]) null);
1189 }
1190 }
1191
1192 /**
1193 * Logs a message produced from the given object.
1194 * <p>
1195 * If the logger is currently enabled for the given log message level then
1196 * a message is logged that, by default, is the result produced from
1197 * calling toString on the given object.
1198 * Otherwise, the object is not operated on.
1199 *
1200 * @implSpec When logging is enabled for the given level, the default
1201 * implementation for this method calls
1202 * {@code this.log(level, (ResourceBundle)null, obj.toString(), (Object[])null);}
1203 *
1204 * @param level the log message level.
1205 * @param obj the object to log.
1206 *
1207 * @throws NullPointerException if {@code level} is {@code null}, or
1208 * {@code obj} is {@code null}.
1209 */
1210 public default void log(Level level, Object obj) {
1211 Objects.requireNonNull(obj);
1212 if (isLoggable(Objects.requireNonNull(level))) {
1213 this.log(level, (ResourceBundle) null, obj.toString(), (Object[]) null);
1214 }
1215 }
1216
1217 /**
1218 * Logs a message associated with a given throwable.
1219 *
1220 * @implSpec The default implementation for this method calls
1221 * {@code this.log(level, (ResourceBundle)null, msg, thrown);}
1222 *
1223 * @param level the log message level.
1224 * @param msg the string message (or a key in the message catalog, if
1225 * this logger is a {@link
1226 * LoggerFinder#getLocalizedLogger(java.lang.String,
1227 * java.util.ResourceBundle, java.lang.reflect.Module) localized logger});
1228 * can be {@code null}.
1229 * @param thrown a {@code Throwable} associated with the log message;
1230 * can be {@code null}.
1231 *
1232 * @throws NullPointerException if {@code level} is {@code null}.
1233 */
1234 public default void log(Level level, String msg, Throwable thrown) {
1235 this.log(level, null, msg, thrown);
1236 }
1237
1238 /**
1239 * Logs a lazily supplied message associated with a given throwable.
1240 * <p>
1241 * If the logger is currently enabled for the given log message level
1242 * then a message is logged that is the result produced by the
1243 * given supplier function. Otherwise, the supplier is not operated on.
1244 *
1245 * @implSpec When logging is enabled for the given level, the default
1246 * implementation for this method calls
1247 * {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), thrown);}
1248 *
1249 * @param level one of the log message level identifiers.
1250 * @param msgSupplier a supplier function that produces a message.
1251 * @param thrown a {@code Throwable} associated with log message;
1252 * can be {@code null}.
1253 *
1254 * @throws NullPointerException if {@code level} is {@code null}, or
1255 * {@code msgSupplier} is {@code null}.
1256 */
1257 public default void log(Level level, Supplier<String> msgSupplier,
1258 Throwable thrown) {
1259 Objects.requireNonNull(msgSupplier);
1260 if (isLoggable(Objects.requireNonNull(level))) {
1261 this.log(level, null, msgSupplier.get(), thrown);
1262 }
1263 }
1264
1265 /**
1266 * Logs a message with an optional list of parameters.
1267 *
1268 * @implSpec The default implementation for this method calls
1269 * {@code this.log(level, (ResourceBundle)null, format, params);}
1270 *
1271 * @param level one of the log message level identifiers.
1272 * @param format the string message format in {@link
1273 * java.text.MessageFormat} format, (or a key in the message
1274 * catalog, if this logger is a {@link
1275 * LoggerFinder#getLocalizedLogger(java.lang.String,
1276 * java.util.ResourceBundle, java.lang.reflect.Module) localized logger});
1277 * can be {@code null}.
1278 * @param params an optional list of parameters to the message (may be
1279 * none).
1280 *
1281 * @throws NullPointerException if {@code level} is {@code null}.
1282 */
1283 public default void log(Level level, String format, Object... params) {
1284 this.log(level, null, format, params);
1285 }
1286
1287 /**
1288 * Logs a localized message associated with a given throwable.
1289 * <p>
1290 * If the given resource bundle is non-{@code null}, the {@code msg}
1291 * string is localized using the given resource bundle.
1292 * Otherwise the {@code msg} string is not localized.
1293 *
1294 * @param level the log message level.
1295 * @param bundle a resource bundle to localize {@code msg}; can be
1296 * {@code null}.
1297 * @param msg the string message (or a key in the message catalog,
1298 * if {@code bundle} is not {@code null}); can be {@code null}.
1299 * @param thrown a {@code Throwable} associated with the log message;
1300 * can be {@code null}.
1301 *
1302 * @throws NullPointerException if {@code level} is {@code null}.
1303 */
1304 public void log(Level level, ResourceBundle bundle, String msg,
1305 Throwable thrown);
1306
1307 /**
1308 * Logs a message with resource bundle and an optional list of
1309 * parameters.
1310 * <p>
1311 * If the given resource bundle is non-{@code null}, the {@code format}
1312 * string is localized using the given resource bundle.
1313 * Otherwise the {@code format} string is not localized.
1314 *
1315 * @param level the log message level.
1316 * @param bundle a resource bundle to localize {@code format}; can be
1317 * {@code null}.
1318 * @param format the string message format in {@link
1319 * java.text.MessageFormat} format, (or a key in the message
1320 * catalog if {@code bundle} is not {@code null}); can be {@code null}.
1321 * @param params an optional list of parameters to the message (may be
1322 * none).
1323 *
1324 * @throws NullPointerException if {@code level} is {@code null}.
1325 */
1326 public void log(Level level, ResourceBundle bundle, String format,
1327 Object... params);
1328
1329
1330 }
1331
1332 /**
1333 * The {@code LoggerFinder} service is responsible for creating, managing,
1334 * and configuring loggers to the underlying framework it uses.
1335 * <p>
1336 * A logger finder is a concrete implementation of this class that has a
1337 * zero-argument constructor and implements the abstract methods defined
1338 * by this class.
1339 * The loggers returned from a logger finder are capable of routing log
1340 * messages to the logging backend this provider supports.
1341 * A given invocation of the Java Runtime maintains a single
1342 * system-wide LoggerFinder instance that is loaded as follows:
1343 * <ul>
1344 * <li>First it finds any custom {@code LoggerFinder} provider
1345 * using the {@link java.util.ServiceLoader} facility with the
1346 * {@linkplain ClassLoader#getSystemClassLoader() system class
1347 * loader}.</li>
1348 * <li>If no {@code LoggerFinder} provider is found, the system default
1349 * {@code LoggerFinder} implementation will be used.</li>
1350 * </ul>
1351 * <p>
1352 * An application can replace the logging backend
1353 * <i>even when the java.logging module is present</i>, by simply providing
1354 * and declaring an implementation of the {@link LoggerFinder} service.
1355 * <p>
1356 * <b>Default Implementation</b>
1357 * <p>
1358 * The system default {@code LoggerFinder} implementation uses
1359 * {@code java.util.logging} as the backend framework when the
1360 * {@code java.logging} module is present.
1361 * It returns a {@linkplain System.Logger logger} instance
1362 * that will route log messages to a {@link java.util.logging.Logger
1363 * java.util.logging.Logger}. Otherwise, if {@code java.logging} is not
1364 * present, the default implementation will return a simple logger
1365 * instance that will route log messages of {@code INFO} level and above to
1366 * the console ({@code System.err}).
1367 * <p>
1368 * <b>Logging Configuration</b>
1369 * <p>
1370 * {@linkplain Logger Logger} instances obtained from the
1371 * {@code LoggerFinder} factory methods are not directly configurable by
1372 * the application. Configuration is the responsibility of the underlying
1373 * logging backend, and usually requires using APIs specific to that backend.
1374 * <p>For the default {@code LoggerFinder} implementation
1375 * using {@code java.util.logging} as its backend, refer to
1376 * {@link java.util.logging java.util.logging} for logging configuration.
1377 * For the default {@code LoggerFinder} implementation returning simple loggers
1378 * when the {@code java.logging} module is absent, the configuration
1379 * is implementation dependent.
1380 * <p>
1381 * Usually an application that uses a logging framework will log messages
1382 * through a logger facade defined (or supported) by that framework.
1383 * Applications that wish to use an external framework should log
1384 * through the facade associated with that framework.
1385 * <p>
1386 * A system class that needs to log messages will typically obtain
1387 * a {@link System.Logger} instance to route messages to the logging
1388 * framework selected by the application.
1389 * <p>
1390 * Libraries and classes that only need loggers to produce log messages
1391 * should not attempt to configure loggers by themselves, as that
1392 * would make them dependent from a specific implementation of the
1393 * {@code LoggerFinder} service.
1394 * <p>
1395 * In addition, when a security manager is present, loggers provided to
1396 * system classes should not be directly configurable through the logging
1397 * backend without requiring permissions.
1398 * <br>
1399 * It is the responsibility of the provider of
1400 * the concrete {@code LoggerFinder} implementation to ensure that
1401 * these loggers are not configured by untrusted code without proper
1402 * permission checks, as configuration performed on such loggers usually
1403 * affects all applications in the same Java Runtime.
1404 * <p>
1405 * <b>Message Levels and Mapping to backend levels</b>
1406 * <p>
1407 * A logger finder is responsible for mapping from a {@code
1408 * System.Logger.Level} to a level supported by the logging backend it uses.
1409 * <br>The default LoggerFinder using {@code java.util.logging} as the backend
1410 * maps {@code System.Logger} levels to
1411 * {@linkplain java.util.logging.Level java.util.logging} levels
1412 * of corresponding severity - as described in {@link Logger.Level
1413 * Logger.Level}.
1414 *
1415 * @see java.lang.System
1416 * @see java.lang.System.Logger
1417 *
1418 * @since 9
1419 */
1420 public static abstract class LoggerFinder {
1421 /**
1422 * The {@code RuntimePermission("loggerFinder")} is
1423 * necessary to subclass and instantiate the {@code LoggerFinder} class,
1424 * as well as to obtain loggers from an instance of that class.
1425 */
1426 static final RuntimePermission LOGGERFINDER_PERMISSION =
1427 new RuntimePermission("loggerFinder");
1428
1429 /**
1430 * Creates a new instance of {@code LoggerFinder}.
1431 *
1432 * @implNote It is recommended that a {@code LoggerFinder} service
1433 * implementation does not perform any heavy initialization in its
1434 * constructor, in order to avoid possible risks of deadlock or class
1435 * loading cycles during the instantiation of the service provider.
1436 *
1437 * @throws SecurityException if a security manager is present and its
1438 * {@code checkPermission} method doesn't allow the
1439 * {@code RuntimePermission("loggerFinder")}.
1440 */
1441 protected LoggerFinder() {
1442 this(checkPermission());
1443 }
1444
1445 private LoggerFinder(Void unused) {
1446 // nothing to do.
1447 }
1448
1449 private static Void checkPermission() {
1450 final SecurityManager sm = System.getSecurityManager();
1451 if (sm != null) {
1452 sm.checkPermission(LOGGERFINDER_PERMISSION);
1453 }
1454 return null;
1455 }
1456
1457 /**
1458 * Returns an instance of {@link Logger Logger}
1459 * for the given {@code module}.
1460 *
1461 * @param name the name of the logger.
1462 * @param module the module for which the logger is being requested.
1463 *
1464 * @return a {@link Logger logger} suitable for use within the given
1465 * module.
1466 * @throws NullPointerException if {@code name} is {@code null} or
1467 * {@code module} is {@code null}.
1468 * @throws SecurityException if a security manager is present and its
1469 * {@code checkPermission} method doesn't allow the
1470 * {@code RuntimePermission("loggerFinder")}.
1471 */
1472 public abstract Logger getLogger(String name, Module module);
1473
1474 /**
1475 * Returns a localizable instance of {@link Logger Logger}
1476 * for the given {@code module}.
1477 * The returned logger will use the provided resource bundle for
1478 * message localization.
1479 *
1480 * @implSpec By default, this method calls {@link
1481 * #getLogger(java.lang.String, java.lang.reflect.Module)
1482 * this.getLogger(name, module)} to obtain a logger, then wraps that
1483 * logger in a {@link Logger} instance where all methods that do not
1484 * take a {@link ResourceBundle} as parameter are redirected to one
1485 * which does - passing the given {@code bundle} for
1486 * localization. So for instance, a call to {@link
1487 * Logger#log(Level, String) Logger.log(Level.INFO, msg)}
1488 * will end up as a call to {@link
1489 * Logger#log(Level, ResourceBundle, String, Object...)
1490 * Logger.log(Level.INFO, bundle, msg, (Object[])null)} on the wrapped
1491 * logger instance.
1492 * Note however that by default, string messages returned by {@link
1493 * java.util.function.Supplier Supplier<String>} will not be
1494 * localized, as it is assumed that such strings are messages which are
1495 * already constructed, rather than keys in a resource bundle.
1496 * <p>
1497 * An implementation of {@code LoggerFinder} may override this method,
1498 * for example, when the underlying logging backend provides its own
1499 * mechanism for localizing log messages, then such a
1500 * {@code LoggerFinder} would be free to return a logger
1501 * that makes direct use of the mechanism provided by the backend.
1502 *
1503 * @param name the name of the logger.
1504 * @param bundle a resource bundle; can be {@code null}.
1505 * @param module the module for which the logger is being requested.
1506 * @return an instance of {@link Logger Logger} which will use the
1507 * provided resource bundle for message localization.
1508 *
1509 * @throws NullPointerException if {@code name} is {@code null} or
1510 * {@code module} is {@code null}.
1511 * @throws SecurityException if a security manager is present and its
1512 * {@code checkPermission} method doesn't allow the
1513 * {@code RuntimePermission("loggerFinder")}.
1514 */
1515 public Logger getLocalizedLogger(String name, ResourceBundle bundle,
1516 Module module) {
1517 return new LocalizedLoggerWrapper<>(getLogger(name, module), bundle);
1518 }
1519
1520 /**
1521 * Returns the {@code LoggerFinder} instance. There is one
1522 * single system-wide {@code LoggerFinder} instance in
1523 * the Java Runtime. See the class specification of how the
1524 * {@link LoggerFinder LoggerFinder} implementation is located and
1525 * loaded.
1526
1527 * @return the {@link LoggerFinder LoggerFinder} instance.
1528 * @throws SecurityException if a security manager is present and its
1529 * {@code checkPermission} method doesn't allow the
1530 * {@code RuntimePermission("loggerFinder")}.
1531 */
1532 public static LoggerFinder getLoggerFinder() {
1533 final SecurityManager sm = System.getSecurityManager();
1534 if (sm != null) {
1535 sm.checkPermission(LOGGERFINDER_PERMISSION);
1536 }
1537 return accessProvider();
1538 }
1539
1540
1541 private static volatile LoggerFinder service;
1542 static LoggerFinder accessProvider() {
1543 // We do not need to synchronize: LoggerFinderLoader will
1544 // always return the same instance, so if we don't have it,
1545 // just fetch it again.
1546 if (service == null) {
1547 PrivilegedAction<LoggerFinder> pa =
1548 () -> LoggerFinderLoader.getLoggerFinder();
1549 service = AccessController.doPrivileged(pa, null,
1550 LOGGERFINDER_PERMISSION);
1551 }
1552 return service;
1553 }
1554
1555 }
1556
1557
1558 /**
1559 * Returns an instance of {@link Logger Logger} for the caller's
1560 * use.
1561 *
1562 * @implSpec
1563 * Instances returned by this method route messages to loggers
1564 * obtained by calling {@link LoggerFinder#getLogger(java.lang.String,
1565 * java.lang.reflect.Module) LoggerFinder.getLogger(name, module)}, where
1566 * {@code module} is the caller's module.
1567 *
1568 * @apiNote
1569 * This method may defer calling the {@link
1570 * LoggerFinder#getLogger(java.lang.String, java.lang.reflect.Module)
1571 * LoggerFinder.getLogger} method to create an actual logger supplied by
1572 * the logging backend, for instance, to allow loggers to be obtained during
1573 * the system initialization time.
1574 *
1575 * @param name the name of the logger.
1576 * @return an instance of {@link Logger} that can be used by the calling
1577 * class.
1578 * @throws NullPointerException if {@code name} is {@code null}.
1579 *
1580 * @since 9
1581 */
1582 @CallerSensitive
1583 public static Logger getLogger(String name) {
1584 Objects.requireNonNull(name);
1585 final Class<?> caller = Reflection.getCallerClass();
1586 return LazyLoggers.getLogger(name, caller.getModule());
1587 }
1588
1589 /**
1590 * Returns a localizable instance of {@link Logger
1591 * Logger} for the caller's use.
1592 * The returned logger will use the provided resource bundle for message
1593 * localization.
1594 *
1595 * @implSpec
1596 * The returned logger will perform message localization as specified
1597 * by {@link LoggerFinder#getLocalizedLogger(java.lang.String,
1598 * java.util.ResourceBundle, java.lang.reflect.Module)
1599 * LoggerFinder.getLocalizedLogger(name, bundle, module}, where
1600 * {@code module} is the caller's module.
1601 *
1602 * @apiNote
1603 * This method is intended to be used after the system is fully initialized.
1604 * This method may trigger the immediate loading and initialization
1605 * of the {@link LoggerFinder} service, which may cause issues if the
1606 * Java Runtime is not ready to initialize the concrete service
1607 * implementation yet.
1608 * System classes which may be loaded early in the boot sequence and
1609 * need to log localized messages should create a logger using
1610 * {@link #getLogger(java.lang.String)} and then use the log methods that
1611 * take a resource bundle as parameter.
1612 *
1613 * @param name the name of the logger.
1614 * @param bundle a resource bundle.
1615 * @return an instance of {@link Logger} which will use the provided
1616 * resource bundle for message localization.
1617 * @throws NullPointerException if {@code name} is {@code null} or
1618 * {@code bundle} is {@code null}.
1619 *
1620 * @since 9
1621 */
1622 @CallerSensitive
1623 public static Logger getLogger(String name, ResourceBundle bundle) {
1624 final ResourceBundle rb = Objects.requireNonNull(bundle);
1625 Objects.requireNonNull(name);
1626 final Class<?> caller = Reflection.getCallerClass();
1627 final SecurityManager sm = System.getSecurityManager();
1628 // We don't use LazyLoggers if a resource bundle is specified.
1629 // Bootstrap sensitive classes in the JDK do not use resource bundles
1630 // when logging. This could be revisited later, if it needs to.
1631 if (sm != null) {
1632 final PrivilegedAction<Logger> pa =
1633 () -> LoggerFinder.accessProvider()
1634 .getLocalizedLogger(name, rb, caller.getModule());
1635 return AccessController.doPrivileged(pa, null,
1636 LoggerFinder.LOGGERFINDER_PERMISSION);
1637 }
1638 return LoggerFinder.accessProvider()
1639 .getLocalizedLogger(name, rb, caller.getModule());
1640 }
1641
1642 /**
1643 * Terminates the currently running Java Virtual Machine. The
1644 * argument serves as a status code; by convention, a nonzero status
1645 * code indicates abnormal termination.
1646 * <p>
1647 * This method calls the <code>exit</code> method in class
1648 * <code>Runtime</code>. This method never returns normally.
1649 * <p>
1650 * The call <code>System.exit(n)</code> is effectively equivalent to
1651 * the call:
1652 * <blockquote><pre>
1653 * Runtime.getRuntime().exit(n)
1654 * </pre></blockquote>
1655 *
1656 * @param status exit status.
1657 * @throws SecurityException
1658 * if a security manager exists and its <code>checkExit</code>
1659 * method doesn't allow exit with the specified status.
1660 * @see java.lang.Runtime#exit(int)
1661 */
1662 public static void exit(int status) {
1663 Runtime.getRuntime().exit(status);
1664 }
1665
1666 /**
1667 * Runs the garbage collector.
1668 * <p>
1669 * Calling the <code>gc</code> method suggests that the Java Virtual
1670 * Machine expend effort toward recycling unused objects in order to
1671 * make the memory they currently occupy available for quick reuse.
1672 * When control returns from the method call, the Java Virtual
1673 * Machine has made a best effort to reclaim space from all discarded
1674 * objects.
1675 * <p>
1676 * The call <code>System.gc()</code> is effectively equivalent to the
1677 * call:
1678 * <blockquote><pre>
1679 * Runtime.getRuntime().gc()
1680 * </pre></blockquote>
1681 *
1682 * @see java.lang.Runtime#gc()
1683 */
1684 public static void gc() {
1685 Runtime.getRuntime().gc();
1686 }
1687
1688 /**
1689 * Runs the finalization methods of any objects pending finalization.
1690 * <p>
1691 * Calling this method suggests that the Java Virtual Machine expend
1692 * effort toward running the <code>finalize</code> methods of objects
1693 * that have been found to be discarded but whose <code>finalize</code>
1694 * methods have not yet been run. When control returns from the
1695 * method call, the Java Virtual Machine has made a best effort to
1696 * complete all outstanding finalizations.
1697 * <p>
1698 * The call <code>System.runFinalization()</code> is effectively
1699 * equivalent to the call:
1700 * <blockquote><pre>
1701 * Runtime.getRuntime().runFinalization()
1702 * </pre></blockquote>
1703 *
1704 * @see java.lang.Runtime#runFinalization()
1705 */
1706 public static void runFinalization() {
1707 Runtime.getRuntime().runFinalization();
1708 }
1709
1710 /**
1711 * Enable or disable finalization on exit; doing so specifies that the
1712 * finalizers of all objects that have finalizers that have not yet been
1713 * automatically invoked are to be run before the Java runtime exits.
1714 * By default, finalization on exit is disabled.
1715 *
1716 * <p>If there is a security manager,
1717 * its <code>checkExit</code> method is first called
1718 * with 0 as its argument to ensure the exit is allowed.
1719 * This could result in a SecurityException.
1720 *
1721 * @deprecated This method is inherently unsafe. It may result in
1722 * finalizers being called on live objects while other threads are
1723 * concurrently manipulating those objects, resulting in erratic
1724 * behavior or deadlock.
1725 * @param value indicating enabling or disabling of finalization
1726 * @throws SecurityException
1727 * if a security manager exists and its <code>checkExit</code>
1728 * method doesn't allow the exit.
1729 *
1730 * @see java.lang.Runtime#exit(int)
1731 * @see java.lang.Runtime#gc()
1732 * @see java.lang.SecurityManager#checkExit(int)
1733 * @since 1.1
1734 */
1735 @Deprecated
1736 public static void runFinalizersOnExit(boolean value) {
1737 Runtime.runFinalizersOnExit(value);
1738 }
1739
1740 /**
1741 * Loads the native library specified by the filename argument. The filename
1742 * argument must be an absolute path name.
1743 *
1744 * If the filename argument, when stripped of any platform-specific library
1745 * prefix, path, and file extension, indicates a library whose name is,
1746 * for example, L, and a native library called L is statically linked
1747 * with the VM, then the JNI_OnLoad_L function exported by the library
1748 * is invoked rather than attempting to load a dynamic library.
1749 * A filename matching the argument does not have to exist in the
1750 * file system.
1751 * See the JNI Specification for more details.
1752 *
1753 * Otherwise, the filename argument is mapped to a native library image in
1754 * an implementation-dependent manner.
1755 *
1756 * <p>
1757 * The call <code>System.load(name)</code> is effectively equivalent
1758 * to the call:
1759 * <blockquote><pre>
1760 * Runtime.getRuntime().load(name)
1761 * </pre></blockquote>
1762 *
1763 * @param filename the file to load.
1764 * @exception SecurityException if a security manager exists and its
1765 * <code>checkLink</code> method doesn't allow
1766 * loading of the specified dynamic library
1767 * @exception UnsatisfiedLinkError if either the filename is not an
1768 * absolute path name, the native library is not statically
1769 * linked with the VM, or the library cannot be mapped to
1770 * a native library image by the host system.
1771 * @exception NullPointerException if <code>filename</code> is
1772 * <code>null</code>
1773 * @see java.lang.Runtime#load(java.lang.String)
1774 * @see java.lang.SecurityManager#checkLink(java.lang.String)
1775 */
1776 @CallerSensitive
1777 public static void load(String filename) {
1778 Runtime.getRuntime().load0(Reflection.getCallerClass(), filename);
1779 }
1780
1781 /**
1782 * Loads the native library specified by the <code>libname</code>
1783 * argument. The <code>libname</code> argument must not contain any platform
1784 * specific prefix, file extension or path. If a native library
1785 * called <code>libname</code> is statically linked with the VM, then the
1786 * JNI_OnLoad_<code>libname</code> function exported by the library is invoked.
1787 * See the JNI Specification for more details.
1788 *
1789 * Otherwise, the libname argument is loaded from a system library
1790 * location and mapped to a native library image in an implementation-
1791 * dependent manner.
1792 * <p>
1793 * The call <code>System.loadLibrary(name)</code> is effectively
1794 * equivalent to the call
1795 * <blockquote><pre>
1796 * Runtime.getRuntime().loadLibrary(name)
1797 * </pre></blockquote>
1798 *
1799 * @param libname the name of the library.
1800 * @exception SecurityException if a security manager exists and its
1801 * <code>checkLink</code> method doesn't allow
1802 * loading of the specified dynamic library
1803 * @exception UnsatisfiedLinkError if either the libname argument
1804 * contains a file path, the native library is not statically
1805 * linked with the VM, or the library cannot be mapped to a
1806 * native library image by the host system.
1807 * @exception NullPointerException if <code>libname</code> is
1808 * <code>null</code>
1809 * @see java.lang.Runtime#loadLibrary(java.lang.String)
1810 * @see java.lang.SecurityManager#checkLink(java.lang.String)
1811 */
1812 @CallerSensitive
1813 public static void loadLibrary(String libname) {
1814 Runtime.getRuntime().loadLibrary0(Reflection.getCallerClass(), libname);
1815 }
1816
1817 /**
1818 * Maps a library name into a platform-specific string representing
1819 * a native library.
1820 *
1821 * @param libname the name of the library.
1822 * @return a platform-dependent native library name.
1823 * @exception NullPointerException if <code>libname</code> is
1824 * <code>null</code>
1825 * @see java.lang.System#loadLibrary(java.lang.String)
1826 * @see java.lang.ClassLoader#findLibrary(java.lang.String)
1827 * @since 1.2
1828 */
1829 public static native String mapLibraryName(String libname);
1830
1831 /**
1832 * Create PrintStream for stdout/err based on encoding.
1833 */
1834 private static PrintStream newPrintStream(FileOutputStream fos, String enc) {
1835 if (enc != null) {
1836 try {
1837 return new PrintStream(new BufferedOutputStream(fos, 128), true, enc);
1838 } catch (UnsupportedEncodingException uee) {}
1839 }
1840 return new PrintStream(new BufferedOutputStream(fos, 128), true);
1841 }
1842
1843 /**
1844 * Initialize the system class. Called after thread initialization.
1845 */
1846 private static void initPhase1() {
1847
1848 // VM might invoke JNU_NewStringPlatform() to set those encoding
1849 // sensitive properties (user.home, user.name, boot.class.path, etc.)
1850 // during "props" initialization, in which it may need access, via
1851 // System.getProperty(), to the related system encoding property that
1852 // have been initialized (put into "props") at early stage of the
1853 // initialization. So make sure the "props" is available at the
1854 // very beginning of the initialization and all system properties to
1855 // be put into it directly.
1856 props = new Properties();
1857 initProperties(props); // initialized by the VM
1858
1859 // There are certain system configurations that may be controlled by
1860 // VM options such as the maximum amount of direct memory and
1861 // Integer cache size used to support the object identity semantics
1862 // of autoboxing. Typically, the library will obtain these values
1863 // from the properties set by the VM. If the properties are for
1864 // internal implementation use only, these properties should be
1865 // removed from the system properties.
1866 //
1867 // See java.lang.Integer.IntegerCache and the
1868 // VM.saveAndRemoveProperties method for example.
1869 //
1870 // Save a private copy of the system properties object that
1871 // can only be accessed by the internal implementation. Remove
1872 // certain system properties that are not intended for public access.
1873 VM.saveAndRemoveProperties(props);
1874
1875 lineSeparator = props.getProperty("line.separator");
1876 VersionProps.init();
1877
1878 FileInputStream fdIn = new FileInputStream(FileDescriptor.in);
1879 FileOutputStream fdOut = new FileOutputStream(FileDescriptor.out);
1880 FileOutputStream fdErr = new FileOutputStream(FileDescriptor.err);
1881 setIn0(new BufferedInputStream(fdIn));
1882 setOut0(newPrintStream(fdOut, props.getProperty("sun.stdout.encoding")));
1883 setErr0(newPrintStream(fdErr, props.getProperty("sun.stderr.encoding")));
1884
1885 // Load the zip library now in order to keep java.util.zip.ZipFile
1886 // from trying to use itself to load this library later.
1887 loadLibrary("zip");
1888
1889 // Setup Java signal handlers for HUP, TERM, and INT (where available).
1890 Terminator.setup();
1891
1892 // Initialize any miscellaneous operating system settings that need to be
1893 // set for the class libraries. Currently this is no-op everywhere except
1894 // for Windows where the process-wide error mode is set before the java.io
1895 // classes are used.
1896 VM.initializeOSEnvironment();
1897
1898 // The main thread is not added to its thread group in the same
1899 // way as other threads; we must do it ourselves here.
1900 Thread current = Thread.currentThread();
1901 current.getThreadGroup().add(current);
1902
1903 // register shared secrets
1904 setJavaLangAccess();
1905
1906 // Subsystems that are invoked during initialization can invoke
1907 // VM.isBooted() in order to avoid doing things that should
1908 // wait until the VM is fully initialized. The initialization level
1909 // is incremented from 0 to 1 here to indicate the first phase of
1910 // initialization has completed.
1911 // IMPORTANT: Ensure that this remains the last initialization action!
1912 VM.initLevel(1);
1913 }
1914
1915 // @see #initPhase2()
1916 private static Layer bootLayer;
1917
1918 /*
1919 * Invoked by VM. Phase 2 module system initialization.
1920 * Only classes in java.base can be loaded in this phase.
1921 */
1922 private static void initPhase2() {
1923 // initialize the module system
1924 System.bootLayer = ModuleBootstrap.boot();
1925
1926 // base module needs to be loose (CODETOOLS-7901619)
1927 Module base = Object.class.getModule();
1928 Modules.addReads(base, null);
1929
1930 // module system initialized
1931 VM.initLevel(2);
1932 }
1933
1934 /*
1935 * Invoked by VM. Phase 3 is the final system initialization:
1936 * 1. set security manager
1937 * 2. set system class loader
1938 * 3. set TCCL
1939 *
1940 * This method must be called after the module system initialization.
1941 * The security manager and system class loader may be custom class from
1942 * the application classpath or modulepath.
1943 */
1944 private static void initPhase3() {
1945 // set security manager
1946 String cn = System.getProperty("java.security.manager");
1947 if (cn != null) {
1948 if (cn.isEmpty() || "default".equals(cn)) {
1949 System.setSecurityManager(new SecurityManager());
1950 } else {
1951 try {
1952 Class<?> c = Class.forName(cn, false, ClassLoader.getBuiltinAppClassLoader());
1953 Constructor<?> ctor = c.getConstructor();
1954 // Must be a public subclass of SecurityManager with
1955 // a public no-arg constructor
1956 if (!SecurityManager.class.isAssignableFrom(c) ||
1957 !Modifier.isPublic(c.getModifiers()) ||
1958 !Modifier.isPublic(ctor.getModifiers())) {
1959 throw new Error("Could not create SecurityManager: " + ctor.toString());
1960 }
1961 // custom security manager implementation may be in unnamed module
1962 // or a named module but non-exported package
1963 ctor.setAccessible(true);
1964 SecurityManager sm = (SecurityManager) ctor.newInstance();
1965 System.setSecurityManager(sm);
1966 } catch (Exception e) {
1967 throw new Error("Could not create SecurityManager", e);
1968 }
1969 }
1970 }
1971
1972 // initializing the system class loader
1973 VM.initLevel(3);
1974
1975 // system class loader initialized
1976 ClassLoader scl = ClassLoader.initSystemClassLoader();
1977
1978 // set TCCL
1979 Thread.currentThread().setContextClassLoader(scl);
1980
1981 // system is fully initialized
1982 VM.initLevel(4);
1983 }
1984
1985 private static void setJavaLangAccess() {
1986 // Allow privileged classes outside of java.lang
1987 SharedSecrets.setJavaLangAccess(new JavaLangAccess(){
1988 public sun.reflect.ConstantPool getConstantPool(Class<?> klass) {
1989 return klass.getConstantPool();
1990 }
1991 public boolean casAnnotationType(Class<?> klass, AnnotationType oldType, AnnotationType newType) {
1992 return klass.casAnnotationType(oldType, newType);
1993 }
1994 public AnnotationType getAnnotationType(Class<?> klass) {
1995 return klass.getAnnotationType();
1996 }
1997 public Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap(Class<?> klass) {
1998 return klass.getDeclaredAnnotationMap();
1999 }
2000 public byte[] getRawClassAnnotations(Class<?> klass) {
2001 return klass.getRawAnnotations();
2002 }
2003 public byte[] getRawClassTypeAnnotations(Class<?> klass) {
2004 return klass.getRawTypeAnnotations();
2005 }
2006 public byte[] getRawExecutableTypeAnnotations(Executable executable) {
2007 return Class.getExecutableTypeAnnotationBytes(executable);
2008 }
2009 public <E extends Enum<E>>
2010 E[] getEnumConstantsShared(Class<E> klass) {
2011 return klass.getEnumConstantsShared();
2012 }
2013 public void blockedOn(Thread t, Interruptible b) {
2014 t.blockedOn(b);
2015 }
2016 public void registerShutdownHook(int slot, boolean registerShutdownInProgress, Runnable hook) {
2017 Shutdown.add(slot, registerShutdownInProgress, hook);
2018 }
2019 public String newStringUnsafe(char[] chars) {
2020 return new String(chars, true);
2021 }
2022 public Thread newThreadWithAcc(Runnable target, AccessControlContext acc) {
2023 return new Thread(target, acc);
2024 }
2025 public void invokeFinalize(Object o) throws Throwable {
2026 o.finalize();
2027 }
2028 public Layer getBootLayer() {
2029 return bootLayer;
2030 }
2031 public ServicesCatalog getServicesCatalog(ClassLoader cl) {
2032 return cl.getServicesCatalog();
2033 }
2034 public ServicesCatalog createOrGetServicesCatalog(ClassLoader cl) {
2035 return cl.createOrGetServicesCatalog();
2036 }
2037 public ConcurrentHashMap<?, ?> createOrGetClassLoaderValueMap(ClassLoader cl) {
2038 return cl.createOrGetClassLoaderValueMap();
2039 }
2040 public Class<?> findBootstrapClassOrNull(ClassLoader cl, String name) {
2041 return cl.findBootstrapClassOrNull(name);
2042 }
2043 public URL findResource(ClassLoader cl, String mn, String name) throws IOException {
2044 return cl.findResource(mn, name);
2045 }
2046 public Stream<Package> packages(ClassLoader cl) {
2047 return cl.packages();
2048 }
2049 public Package definePackage(ClassLoader cl, String name, Module module) {
2050 return cl.definePackage(name, module);
2051 }
2052 public String fastUUID(long lsb, long msb) {
2053 return Long.fastUUID(lsb, msb);
2054 }
2055 });
2056 }
2057 }