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25 
26 package java.util.logging;
27 import java.util.ArrayList;
28 import java.util.HashMap;
29 import java.util.List;
30 import java.util.Locale;
31 import java.util.Map;
32 import java.util.ResourceBundle;
33 
34 /**
35  * The Level class defines a set of standard logging levels that
36  * can be used to control logging output.  The logging Level objects
37  * are ordered and are specified by ordered integers.  Enabling logging
38  * at a given level also enables logging at all higher levels.
39  * <p>
40  * Clients should normally use the predefined Level constants such
41  * as Level.SEVERE.
42  * <p>
43  * The levels in descending order are:
44  * <ul>
45  * <li>SEVERE (highest value)
46  * <li>WARNING
47  * <li>INFO
48  * <li>CONFIG
49  * <li>FINE
50  * <li>FINER
51  * <li>FINEST  (lowest value)
52  * </ul>
53  * In addition there is a level OFF that can be used to turn
54  * off logging, and a level ALL that can be used to enable
55  * logging of all messages.
56  * <p>
57  * It is possible for third parties to define additional logging
58  * levels by subclassing Level.  In such cases subclasses should
59  * take care to chose unique integer level values and to ensure that
60  * they maintain the Object uniqueness property across serialization
61  * by defining a suitable readResolve method.
62  *
63  * @since 1.4
64  */
65 
66 public class Level implements java.io.Serializable {
67     private static final String defaultBundle = "sun.util.logging.resources.logging";
68 
69     /**
70      * @serial  The non-localized name of the level.
71      */
72     private final String name;
73 
74     /**
75      * @serial  The integer value of the level.
76      */
77     private final int value;
78 
79     /**
80      * @serial The resource bundle name to be used in localizing the level name.
81      */
82     private final String resourceBundleName;
83 
84     // localized level name
85     private transient String localizedLevelName;
86     private transient Locale cachedLocale;
87 
88     /**
89      * OFF is a special level that can be used to turn off logging.
90      * This level is initialized to <CODE>Integer.MAX_VALUE</CODE>.
91      */
92     public static final Level OFF = new Level("OFF",Integer.MAX_VALUE, defaultBundle);
93 
94     /**
95      * SEVERE is a message level indicating a serious failure.
96      * <p>
97      * In general SEVERE messages should describe events that are
98      * of considerable importance and which will prevent normal
99      * program execution.   They should be reasonably intelligible
100      * to end users and to system administrators.
101      * This level is initialized to <CODE>1000</CODE>.
102      */
103     public static final Level SEVERE = new Level("SEVERE",1000, defaultBundle);
104 
105     /**
106      * WARNING is a message level indicating a potential problem.
107      * <p>
108      * In general WARNING messages should describe events that will
109      * be of interest to end users or system managers, or which
110      * indicate potential problems.
111      * This level is initialized to <CODE>900</CODE>.
112      */
113     public static final Level WARNING = new Level("WARNING", 900, defaultBundle);
114 
115     /**
116      * INFO is a message level for informational messages.
117      * <p>
118      * Typically INFO messages will be written to the console
119      * or its equivalent.  So the INFO level should only be
120      * used for reasonably significant messages that will
121      * make sense to end users and system administrators.
122      * This level is initialized to <CODE>800</CODE>.
123      */
124     public static final Level INFO = new Level("INFO", 800, defaultBundle);
125 
126     /**
127      * CONFIG is a message level for static configuration messages.
128      * <p>
129      * CONFIG messages are intended to provide a variety of static
130      * configuration information, to assist in debugging problems
131      * that may be associated with particular configurations.
132      * For example, CONFIG message might include the CPU type,
133      * the graphics depth, the GUI look-and-feel, etc.
134      * This level is initialized to <CODE>700</CODE>.
135      */
136     public static final Level CONFIG = new Level("CONFIG", 700, defaultBundle);
137 
138     /**
139      * FINE is a message level providing tracing information.
140      * <p>
141      * All of FINE, FINER, and FINEST are intended for relatively
142      * detailed tracing.  The exact meaning of the three levels will
143      * vary between subsystems, but in general, FINEST should be used
144      * for the most voluminous detailed output, FINER for somewhat
145      * less detailed output, and FINE for the  lowest volume (and
146      * most important) messages.
147      * <p>
148      * In general the FINE level should be used for information
149      * that will be broadly interesting to developers who do not have
150      * a specialized interest in the specific subsystem.
151      * <p>
152      * FINE messages might include things like minor (recoverable)
153      * failures.  Issues indicating potential performance problems
154      * are also worth logging as FINE.
155      * This level is initialized to <CODE>500</CODE>.
156      */
157     public static final Level FINE = new Level("FINE", 500, defaultBundle);
158 
159     /**
160      * FINER indicates a fairly detailed tracing message.
161      * By default logging calls for entering, returning, or throwing
162      * an exception are traced at this level.
163      * This level is initialized to <CODE>400</CODE>.
164      */
165     public static final Level FINER = new Level("FINER", 400, defaultBundle);
166 
167     /**
168      * FINEST indicates a highly detailed tracing message.
169      * This level is initialized to <CODE>300</CODE>.
170      */
171     public static final Level FINEST = new Level("FINEST", 300, defaultBundle);
172 
173     /**
174      * ALL indicates that all messages should be logged.
175      * This level is initialized to <CODE>Integer.MIN_VALUE</CODE>.
176      */
177     public static final Level ALL = new Level("ALL", Integer.MIN_VALUE, defaultBundle);
178 
179     /**
180      * Create a named Level with a given integer value.
181      * <p>
182      * Note that this constructor is "protected" to allow subclassing.
183      * In general clients of logging should use one of the constant Level
184      * objects such as SEVERE or FINEST.  However, if clients need to
185      * add new logging levels, they may subclass Level and define new
186      * constants.
187      * @param name  the name of the Level, for example "SEVERE".
188      * @param value an integer value for the level.
189      * @throws NullPointerException if the name is null
190      */
Level(String name, int value)191     protected Level(String name, int value) {
192         this(name, value, null);
193     }
194 
195     /**
196      * Create a named Level with a given integer value and a
197      * given localization resource name.
198      * <p>
199      * @param name  the name of the Level, for example "SEVERE".
200      * @param value an integer value for the level.
201      * @param resourceBundleName name of a resource bundle to use in
202      *    localizing the given name. If the resourceBundleName is null
203      *    or an empty string, it is ignored.
204      * @throws NullPointerException if the name is null
205      */
Level(String name, int value, String resourceBundleName)206     protected Level(String name, int value, String resourceBundleName) {
207         this(name, value, resourceBundleName, true);
208     }
209 
210     // private constructor to specify whether this instance should be added
211     // to the KnownLevel list from which Level.parse method does its look up
Level(String name, int value, String resourceBundleName, boolean visible)212     private Level(String name, int value, String resourceBundleName, boolean visible) {
213         if (name == null) {
214             throw new NullPointerException();
215         }
216         this.name = name;
217         this.value = value;
218         this.resourceBundleName = resourceBundleName;
219         this.localizedLevelName = resourceBundleName == null ? name : null;
220         this.cachedLocale = null;
221         if (visible) {
222             KnownLevel.add(this);
223         }
224     }
225 
226     /**
227      * Return the level's localization resource bundle name, or
228      * null if no localization bundle is defined.
229      *
230      * @return localization resource bundle name
231      */
getResourceBundleName()232     public String getResourceBundleName() {
233         return resourceBundleName;
234     }
235 
236     /**
237      * Return the non-localized string name of the Level.
238      *
239      * @return non-localized name
240      */
getName()241     public String getName() {
242         return name;
243     }
244 
245     /**
246      * Return the localized string name of the Level, for
247      * the current default locale.
248      * <p>
249      * If no localization information is available, the
250      * non-localized name is returned.
251      *
252      * @return localized name
253      */
getLocalizedName()254     public String getLocalizedName() {
255         return getLocalizedLevelName();
256     }
257 
258     // package-private getLevelName() is used by the implementation
259     // instead of getName() to avoid calling the subclass's version
getLevelName()260     final String getLevelName() {
261         return this.name;
262     }
263 
computeLocalizedLevelName(Locale newLocale)264     private String computeLocalizedLevelName(Locale newLocale) {
265         // Android-change: Use Thread.currentThread().getContextClassLoader(),
266         // otherwise we might get a BootClassLoader.
267         ResourceBundle rb = ResourceBundle.getBundle(resourceBundleName, newLocale,
268                                                      Thread.currentThread().getContextClassLoader());
269         final String localizedName = rb.getString(name);
270 
271         final boolean isDefaultBundle = defaultBundle.equals(resourceBundleName);
272         if (!isDefaultBundle) return localizedName;
273 
274         // This is a trick to determine whether the name has been translated
275         // or not. If it has not been translated, we need to use Locale.ROOT
276         // when calling toUpperCase().
277         final Locale rbLocale = rb.getLocale();
278         final Locale locale =
279                 Locale.ROOT.equals(rbLocale)
280                 || name.equals(localizedName.toUpperCase(Locale.ROOT))
281                 ? Locale.ROOT : rbLocale;
282 
283         // ALL CAPS in a resource bundle's message indicates no translation
284         // needed per Oracle translation guideline.  To workaround this
285         // in Oracle JDK implementation, convert the localized level name
286         // to uppercase for compatibility reason.
287         return Locale.ROOT.equals(locale) ? name : localizedName.toUpperCase(locale);
288     }
289 
290     // Avoid looking up the localizedLevelName twice if we already
291     // have it.
getCachedLocalizedLevelName()292     final String getCachedLocalizedLevelName() {
293 
294         if (localizedLevelName != null) {
295             if (cachedLocale != null) {
296                 if (cachedLocale.equals(Locale.getDefault())) {
297                     // OK: our cached value was looked up with the same
298                     //     locale. We can use it.
299                     return localizedLevelName;
300                 }
301             }
302         }
303 
304         if (resourceBundleName == null) {
305             // No resource bundle: just use the name.
306             return name;
307         }
308 
309         // We need to compute the localized name.
310         // Either because it's the first time, or because our cached
311         // value is for a different locale. Just return null.
312         return null;
313     }
314 
getLocalizedLevelName()315     final synchronized String getLocalizedLevelName() {
316 
317         // See if we have a cached localized name
318         final String cachedLocalizedName = getCachedLocalizedLevelName();
319         if (cachedLocalizedName != null) {
320             return cachedLocalizedName;
321         }
322 
323         // No cached localized name or cache invalid.
324         // Need to compute the localized name.
325         final Locale newLocale = Locale.getDefault();
326         try {
327             localizedLevelName = computeLocalizedLevelName(newLocale);
328         } catch (Exception ex) {
329             localizedLevelName = name;
330         }
331         cachedLocale = newLocale;
332         return localizedLevelName;
333     }
334 
335     // Returns a mirrored Level object that matches the given name as
336     // specified in the Level.parse method.  Returns null if not found.
337     //
338     // It returns the same Level object as the one returned by Level.parse
339     // method if the given name is a non-localized name or integer.
340     //
341     // If the name is a localized name, findLevel and parse method may
342     // return a different level value if there is a custom Level subclass
343     // that overrides Level.getLocalizedName() to return a different string
344     // than what's returned by the default implementation.
345     //
findLevel(String name)346     static Level findLevel(String name) {
347         if (name == null) {
348             throw new NullPointerException();
349         }
350 
351         KnownLevel level;
352 
353         // Look for a known Level with the given non-localized name.
354         level = KnownLevel.findByName(name);
355         if (level != null) {
356             return level.mirroredLevel;
357         }
358 
359         // Now, check if the given name is an integer.  If so,
360         // first look for a Level with the given value and then
361         // if necessary create one.
362         try {
363             int x = Integer.parseInt(name);
364             level = KnownLevel.findByValue(x);
365             if (level == null) {
366                 // add new Level
367                 Level levelObject = new Level(name, x);
368                 level = KnownLevel.findByValue(x);
369             }
370             return level.mirroredLevel;
371         } catch (NumberFormatException ex) {
372             // Not an integer.
373             // Drop through.
374         }
375 
376         level = KnownLevel.findByLocalizedLevelName(name);
377         if (level != null) {
378             return level.mirroredLevel;
379         }
380 
381         return null;
382     }
383 
384     /**
385      * Returns a string representation of this Level.
386      *
387      * @return the non-localized name of the Level, for example "INFO".
388      */
389     @Override
toString()390     public final String toString() {
391         return name;
392     }
393 
394     /**
395      * Get the integer value for this level.  This integer value
396      * can be used for efficient ordering comparisons between
397      * Level objects.
398      * @return the integer value for this level.
399      */
intValue()400     public final int intValue() {
401         return value;
402     }
403 
404     private static final long serialVersionUID = -8176160795706313070L;
405 
406     // Serialization magic to prevent "doppelgangers".
407     // This is a performance optimization.
readResolve()408     private Object readResolve() {
409         KnownLevel o = KnownLevel.matches(this);
410         if (o != null) {
411             return o.levelObject;
412         }
413 
414         // Woops.  Whoever sent us this object knows
415         // about a new log level.  Add it to our list.
416         Level level = new Level(this.name, this.value, this.resourceBundleName);
417         return level;
418     }
419 
420     /**
421      * Parse a level name string into a Level.
422      * <p>
423      * The argument string may consist of either a level name
424      * or an integer value.
425      * <p>
426      * For example:
427      * <ul>
428      * <li>     "SEVERE"
429      * <li>     "1000"
430      * </ul>
431      *
432      * @param  name   string to be parsed
433      * @throws NullPointerException if the name is null
434      * @throws IllegalArgumentException if the value is not valid.
435      * Valid values are integers between <CODE>Integer.MIN_VALUE</CODE>
436      * and <CODE>Integer.MAX_VALUE</CODE>, and all known level names.
437      * Known names are the levels defined by this class (e.g., <CODE>FINE</CODE>,
438      * <CODE>FINER</CODE>, <CODE>FINEST</CODE>), or created by this class with
439      * appropriate package access, or new levels defined or created
440      * by subclasses.
441      *
442      * @return The parsed value. Passing an integer that corresponds to a known name
443      * (e.g., 700) will return the associated name (e.g., <CODE>CONFIG</CODE>).
444      * Passing an integer that does not (e.g., 1) will return a new level name
445      * initialized to that value.
446      */
parse(String name)447     public static synchronized Level parse(String name) throws IllegalArgumentException {
448         // Check that name is not null.
449         name.length();
450 
451         KnownLevel level;
452 
453         // Look for a known Level with the given non-localized name.
454         level = KnownLevel.findByName(name);
455         if (level != null) {
456             return level.levelObject;
457         }
458 
459         // Now, check if the given name is an integer.  If so,
460         // first look for a Level with the given value and then
461         // if necessary create one.
462         try {
463             int x = Integer.parseInt(name);
464             level = KnownLevel.findByValue(x);
465             if (level == null) {
466                 // add new Level
467                 Level levelObject = new Level(name, x);
468                 level = KnownLevel.findByValue(x);
469             }
470             return level.levelObject;
471         } catch (NumberFormatException ex) {
472             // Not an integer.
473             // Drop through.
474         }
475 
476         // Finally, look for a known level with the given localized name,
477         // in the current default locale.
478         // This is relatively expensive, but not excessively so.
479         level = KnownLevel.findByLocalizedLevelName(name);
480         if (level != null) {
481             return level.levelObject;
482         }
483 
484         // OK, we've tried everything and failed
485         throw new IllegalArgumentException("Bad level \"" + name + "\"");
486     }
487 
488     /**
489      * Compare two objects for value equality.
490      * @return true if and only if the two objects have the same level value.
491      */
492     @Override
equals(Object ox)493     public boolean equals(Object ox) {
494         try {
495             Level lx = (Level)ox;
496             return (lx.value == this.value);
497         } catch (Exception ex) {
498             return false;
499         }
500     }
501 
502     /**
503      * Generate a hashcode.
504      * @return a hashcode based on the level value
505      */
506     @Override
hashCode()507     public int hashCode() {
508         return this.value;
509     }
510 
511     // KnownLevel class maintains the global list of all known levels.
512     // The API allows multiple custom Level instances of the same name/value
513     // be created. This class provides convenient methods to find a level
514     // by a given name, by a given value, or by a given localized name.
515     //
516     // KnownLevel wraps the following Level objects:
517     // 1. levelObject:   standard Level object or custom Level object
518     // 2. mirroredLevel: Level object representing the level specified in the
519     //                   logging configuration.
520     //
521     // Level.getName, Level.getLocalizedName, Level.getResourceBundleName methods
522     // are non-final but the name and resource bundle name are parameters to
523     // the Level constructor.  Use the mirroredLevel object instead of the
524     // levelObject to prevent the logging framework to execute foreign code
525     // implemented by untrusted Level subclass.
526     //
527     // Implementation Notes:
528     // If Level.getName, Level.getLocalizedName, Level.getResourceBundleName methods
529     // were final, the following KnownLevel implementation can be removed.
530     // Future API change should take this into consideration.
531     static final class KnownLevel {
532         private static Map<String, List<KnownLevel>> nameToLevels = new HashMap<>();
533         private static Map<Integer, List<KnownLevel>> intToLevels = new HashMap<>();
534         final Level levelObject;     // instance of Level class or Level subclass
535         final Level mirroredLevel;   // mirror of the custom Level
KnownLevel(Level l)536         KnownLevel(Level l) {
537             this.levelObject = l;
538             if (l.getClass() == Level.class) {
539                 this.mirroredLevel = l;
540             } else {
541                 // this mirrored level object is hidden
542                 this.mirroredLevel = new Level(l.name, l.value, l.resourceBundleName, false);
543             }
544         }
545 
add(Level l)546         static synchronized void add(Level l) {
547             // the mirroredLevel object is always added to the list
548             // before the custom Level instance
549             KnownLevel o = new KnownLevel(l);
550             List<KnownLevel> list = nameToLevels.get(l.name);
551             if (list == null) {
552                 list = new ArrayList<>();
553                 nameToLevels.put(l.name, list);
554             }
555             list.add(o);
556 
557             list = intToLevels.get(l.value);
558             if (list == null) {
559                 list = new ArrayList<>();
560                 intToLevels.put(l.value, list);
561             }
562             list.add(o);
563         }
564 
565         // Returns a KnownLevel with the given non-localized name.
findByName(String name)566         static synchronized KnownLevel findByName(String name) {
567             List<KnownLevel> list = nameToLevels.get(name);
568             if (list != null) {
569                 return list.get(0);
570             }
571             return null;
572         }
573 
574         // Returns a KnownLevel with the given value.
findByValue(int value)575         static synchronized KnownLevel findByValue(int value) {
576             List<KnownLevel> list = intToLevels.get(value);
577             if (list != null) {
578                 return list.get(0);
579             }
580             return null;
581         }
582 
583         // Returns a KnownLevel with the given localized name matching
584         // by calling the Level.getLocalizedLevelName() method (i.e. found
585         // from the resourceBundle associated with the Level object).
586         // This method does not call Level.getLocalizedName() that may
587         // be overridden in a subclass implementation
findByLocalizedLevelName(String name)588         static synchronized KnownLevel findByLocalizedLevelName(String name) {
589             for (List<KnownLevel> levels : nameToLevels.values()) {
590                 for (KnownLevel l : levels) {
591                     String lname = l.levelObject.getLocalizedLevelName();
592                     if (name.equals(lname)) {
593                         return l;
594                     }
595                 }
596             }
597             return null;
598         }
599 
matches(Level l)600         static synchronized KnownLevel matches(Level l) {
601             List<KnownLevel> list = nameToLevels.get(l.name);
602             if (list != null) {
603                 for (KnownLevel level : list) {
604                     Level other = level.mirroredLevel;
605                     Class<? extends Level> type = level.levelObject.getClass();
606                     if (l.value == other.value &&
607                            (l.resourceBundleName == other.resourceBundleName ||
608                                (l.resourceBundleName != null &&
609                                 l.resourceBundleName.equals(other.resourceBundleName)))) {
610                         if (type == l.getClass()) {
611                             return level;
612                         }
613                     }
614                 }
615             }
616             return null;
617         }
618     }
619 
620 }
621