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