Holger,
you are right: PlatformLogger does not care about custom Level
implementations because it relies on j.u.l.Logger to decide if the message
should be logged or not:
609 public boolean isLoggable(int level) {
610 return LoggingSupport.isLoggable(javaLogger, getLevel(level));
611 }
The former Map<Integer, Object> levelObjects I removed was only used to get
the j.u.l.Level instance corresponding to a PlatformLogger's level which
are defined as int constants.
FYI, the former map was filled with only j.u.l.Level instances
corresponding to all PlatformLogger's levels:
481 private static void getLevelObjects() {
482 // get all java.util.logging.Level objects
483 int[] levelArray = new int[] {OFF, SEVERE, WARNING,
INFO, CONFIG, FINE, FINER, FINEST, ALL};
484 for (int l : levelArray) {
485 Object level = LoggingSupport.parseLevel(getLevelName(l));
486 levelObjects.put(l, level);
487 }
488 }
I think I did not change the scope of the mapping i.e. PlatformLogger's
levels.
Cheers,
Laurent
2013/3/21 Laurent Bourgès <bourges.laur...@gmail.com>
> Here is the test code that was scrubbed in my previous email.
>
> As you can see in my benchmarks:
> - TLAB has a major impact on Integer allocation overhead
> - patched code is 2x faster (with TLAB enabled)
>
> Test code:
>
> package test;
>
> import java.util.logging.Level;
> import java.util.logging.Logger;
> import sun.util.logging.LoggingSupport;
> import sun.util.logging.PlatformLogger;
>
> /**
> * PlatformLogger patch Test (performance / memory overhead)
> * @author bourgesl
> */
> public class PlatformLoggerTest {
>
> /** logger - enable java.util.logging to enable PlatformLogger using
> JUL */
> private final static Logger logger =
> Logger.getLogger(PlatformLoggerTest.class.getName());
>
> public static void main(String[] args) {
>
> /*
> * 1/ JVM options during tests:
> * -Xms8m -Xmx8m -XX:-UseTLAB -XX:+PrintTLAB
> *
> * JDK7_13 results:
> mars 21, 2013 11:15:07 AM test.PlatformLoggerTest main
> INFO: PlatformLoggerTest: start on JVM1.7.0_13 [Java HotSpot(TM)
> 64-Bit Server VM 23.7-b01]
> *
> INFO: testPerf[100000 iterations]: duration = 61.536460999999996
> ms.
> INFO: PlatformLoggerTest: starting 100000000 iterations ...
> INFO: testPerf[100000000 iterations]: duration = 10485.07581 ms.
> INFO: testPerf[100000000 iterations]: duration = 10639.329926 ms.
> INFO: testPerf[100000000 iterations]: duration = 10903.235198 ms.
> INFO: testPerf[100000000 iterations]: duration = 10728.399372 ms.
> INFO: testPerf[100000000 iterations]: duration = 10643.329983 ms.
> INFO: testPerf[100000000 iterations]: duration = 10720.43687 ms.
> INFO: testPerf[100000000 iterations]: duration =
> 10864.371595999999 ms.
> INFO: testPerf[100000000 iterations]: duration = 10713.845459 ms.
> INFO: testPerf[100000000 iterations]: duration = 10458.257711 ms.
> INFO: testPerf[100000000 iterations]: duration = 10606.267606 ms.
> *
> * OpenJDK8 (+patch):
> mars 21, 2013 11:19:03 AM test.PlatformLoggerTest main
> Infos: PlatformLoggerTest: start on JVM1.8.0-internal [OpenJDK
> 64-Bit Server VM 25.0-b22]
> *
> Infos: testPerf[100000 iterations]: duration = 24.862816 ms.
> Infos: PlatformLoggerTest: starting 100000000 iterations ...
> Infos: testPerf[100000000 iterations]: duration = 1043.957166 ms.
> Infos: testPerf[100000000 iterations]: duration = 1013.602486 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1018.2792629999999 ms.
> Infos: testPerf[100000000 iterations]: duration = 1073.422125 ms.
> Infos: testPerf[100000000 iterations]: duration = 1024.742149 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1021.3166339999999 ms.
> Infos: testPerf[100000000 iterations]: duration = 1014.771751 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1017.6148959999999 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1021.4425389999999 ms.
> Infos: testPerf[100000000 iterations]: duration = 1020.200104 ms.
> *
> * 2/ JVM options during tests:
> * -Xms8m -Xmx8m -XX:+UseTLAB
> *
> * JDK7_13 results:
> * mars 21, 2013 12:58:37 PM test.PlatformLoggerTest main
> INFO: PlatformLoggerTest: start on JVM1.7.0_13 [Java HotSpot(TM)
> 64-Bit Server VM 23.7-b01]
> *
> INFO: testPerf[100000 iterations]: duration = 55.329637 ms.
> INFO: PlatformLoggerTest: starting 100000000 iterations ...
> INFO: testPerf[100000000 iterations]: duration = 2553.872667 ms.
> INFO: testPerf[100000000 iterations]: duration = 2327.072791 ms.
> INFO: testPerf[100000000 iterations]: duration = 2324.000677 ms.
> INFO: testPerf[100000000 iterations]: duration =
> 2326.0859929999997 ms.
> INFO: testPerf[100000000 iterations]: duration = 2325.34332 ms.
> INFO: testPerf[100000000 iterations]: duration = 2322.579729 ms.
> INFO: testPerf[100000000 iterations]: duration = 2322.170814 ms.
> INFO: testPerf[100000000 iterations]: duration = 2324.055535 ms.
> INFO: testPerf[100000000 iterations]: duration =
> 2432.6784829999997 ms.
> INFO: testPerf[100000000 iterations]: duration = 2335.47692 ms.
> *
> * OpenJDK8 (+patch):
> mars 21, 2013 1:00:30 PM test.PlatformLoggerTest main
> Infos: PlatformLoggerTest: start on JVM1.8.0-internal [OpenJDK
> 64-Bit Server VM 25.0-b22]
> *
> Infos: testPerf[100000 iterations]: duration = 22.091089999999998
> ms.
> Infos: PlatformLoggerTest: starting 100000000 iterations ...
> Infos: testPerf[100000000 iterations]: duration = 1023.84232 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1010.5437909999999 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1004.6675389999999 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1005.2778669999999 ms.
> Infos: testPerf[100000000 iterations]: duration = 1017.892527 ms.
> Infos: testPerf[100000000 iterations]: duration = 1006.359113 ms.
> Infos: testPerf[100000000 iterations]: duration = 1006.2957 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1008.3199189999999 ms.
> Infos: testPerf[100000000 iterations]: duration =
> 1001.7142339999999 ms.
> Infos: testPerf[100000000 iterations]: duration = 997.141141 ms.
> *
> * That's all folks!
> */
>
> // JVM options: -Xms8m -Xmx8m -verbose:gc -XX:-UseTLAB
> -XX:+PrintTLAB
>
> // Note: -XX:-UseTLAB because Thread local allocator is efficient
> to support Integer allocations
>
> logger.info("PlatformLoggerTest: start on JVM" +
> System.getProperty("java.version") + " [" + System.getProperty("
> java.vm.name") + " " + System.getProperty("java.vm.version") + "]");
>
>
> logger.info("PlatformLoggerTest: LoggingSupport.isAvailable() = "
> + LoggingSupport.isAvailable());
>
> PlatformLogger.redirectPlatformLoggers();
>
> final PlatformLogger log = PlatformLogger.getLogger("sun.awt.X11");
>
> log.setLevel(PlatformLogger.INFO);
>
> final boolean testEnabledLogs = false;
>
> logger.info("PlatformLogger: enabled = " + log.isEnabled());
> logger.info("PlatformLogger: level = " + log.getLevel());
>
> /*
> for (Enumeration<String> e =
> LogManager.getLogManager().getLoggerNames(); e.hasMoreElements();) {
> logger.info("PlatformLoggerTest: logger[" + e.nextElement() +
> "]");
> }
> */
>
> // Cleanup before test:
> cleanup();
>
>
> int nLog = 0;
>
> final int WARMUP = 100 * 1000;
>
> long start = System.nanoTime();
>
> for (int i = 0; i < WARMUP; i++) {
>
>
> if (log.isLoggable(PlatformLogger.FINEST)) {
> log.finest("test PlatformLogger.FINEST");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.FINE)) {
> log.fine("test PlatformLogger.FINE");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.FINER)) {
> log.finer("test PlatformLogger.FINER");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.CONFIG)) {
> log.config("test PlatformLogger.CONFIG");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (testEnabledLogs) {
> if (log.isLoggable(PlatformLogger.INFO)) {
> log.info("test PlatformLogger.INFO");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.WARNING)) {
> log.warning("test PlatformLogger.WARNING");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.SEVERE)) {
> log.severe("test PlatformLogger.SEVERE");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.OFF)) {
> log.severe("test PlatformLogger.OFF");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
> }
> }
>
> log.info("testPerf[" + WARMUP + " iterations]: duration = " +
> (1e-6d * (System.nanoTime() - start)) + " ms.");
> log.info("testPerf: nLog = " + nLog);
> cleanup();
>
>
> final int PASS = 10;
> final int N = 100 * 1000 * 1000;
> logger.info("PlatformLoggerTest: starting " + N + " iterations
> ...");
>
> for (int j = 0; j < PASS; j++) {
> nLog = 0;
> start = System.nanoTime();
>
> for (int i = 0; i < N; i++) {
>
>
> if (log.isLoggable(PlatformLogger.FINEST)) {
> log.finest("test PlatformLogger.FINEST");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.FINE)) {
> log.fine("test PlatformLogger.FINE");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.FINER)) {
> log.finer("test PlatformLogger.FINER");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.CONFIG)) {
> log.config("test PlatformLogger.CONFIG");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (testEnabledLogs) {
> if (log.isLoggable(PlatformLogger.INFO)) {
> log.info("test PlatformLogger.INFO");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.WARNING)) {
> log.warning("test PlatformLogger.WARNING");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.SEVERE)) {
> log.severe("test PlatformLogger.SEVERE");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
>
> if (log.isLoggable(PlatformLogger.OFF)) {
> log.severe("test PlatformLogger.OFF");
> nLog++; // ensure hotspot do not skip isLoggable()
> } else {
> nLog--;
> }
> }
> }
>
> log.info("testPerf[" + N + " iterations]: duration = " +
> (1e-6d * (System.nanoTime() - start)) + " ms.");
> log.info("testPerf: nLog = " + nLog);
> cleanup();
> }
>
> try {
> Thread.sleep(1000l);
> } catch (InterruptedException ie) {
> logger.log(Level.SEVERE, "Interrupted", ie);
> }
>
> logger.info("PlatformLoggerTest: exit.");
> }
>
> /**
> * Cleanup (GC + pause)
> */
> private static void cleanup() {
> // Perform GC:
> System.gc();
>
> // pause:
> try {
> Thread.sleep(100l);
> } catch (InterruptedException ie) {
>
> }
> }
> }
>
> 2013/3/21 Laurent Bourgès <bourges.laur...@gmail.com>
>
>> Here is an improved patch tested on JDK7u13 and JDK8 internal build on my
>> machine linux x64:
>> http://jmmc.fr/~bourgesl/share/webrev-8010309/
>>
>> FYI, I removed completely the Map<Integer, Object> levelObjects and used
>> two arrays to perform the PlatformLogger's level (int) to j.u.l.Level
>> mapping:
>>
>> I decided to keep it simple as possible (no enum ...) and used a switch
>> case based on current level occurences:
>>
>> 510 /**
>> 511 * Return the corresponding j.u.l.Level instance
>> 512 * @param level PlatformLogger level as integer
>>
>>
>> 513 * @return Object (j.u.l.Level instance) or null if no matching
>> level
>> 514 */
>> 515 private static Object getLevel(final int level) {
>> 516 if (levelObjects == null) {
>>
>> 517 return null;
>>
>> 518 }
>> 519 // higher occurences first (finest, fine, finer, info)
>> 520 // based on isLoggable(level) calls (03/20/2013)
>> 521 // in jdk project only (including generated sources)
>>
>>
>> 522 switch (level) {
>> 523 case FINEST : return levelObjects[IDX_FINEST]; // 116
>> + 2257 matches in generated files
>> 524 case FINE : return levelObjects[IDX_FINE]; // 270
>>
>>
>> 525 case FINER : return levelObjects[IDX_FINER]; // 157
>> 526 case INFO : return levelObjects[IDX_INFO]; // 39
>> 527 case WARNING : return levelObjects[IDX_WARNING]; // 12
>>
>>
>> 528 case CONFIG : return levelObjects[IDX_CONFIG]; // 6
>> 529 case SEVERE : return levelObjects[IDX_SEVERE]; // 1
>> 530 case OFF : return levelObjects[IDX_OFF]; // 0
>>
>>
>> 531 case ALL : return levelObjects[IDX_ALL]; // 0
>> 532 default : return null;
>> 533 }
>> 534 }
>>
>> I enhanced the PlatformLoggerTest class also and figured out that TLAB
>> optimized Integer allocations but I think the patch is still useful.
>>
>> Can you have a look to the patch ?
>> Should I write a jtreg test (performance / GC issue) ?
>>
>> Cheers,
>> Laurent
>>
>>
>> 2013/3/20 Mandy Chung <mandy.ch...@oracle.com>
>>
>>> Hi Laurent,
>>>
>>> Thank you for signing the OCA. Your contribution is very welcome. You
>>> can submit a patch for this bug (see [1]) to Core libraries group which
>>> owns logging. Jim Gish and I will sponsor it.
>>>
>>> Thanks
>>> Mandy
>>> [1] http://openjdk.java.net/contribute/
>>>
>>>
>>> On 3/20/2013 5:45 AM, Laurent Bourgès wrote:
>>>
>>> Hi mandy,
>>>
>>> Do you want me to propose an improved patch to remove the former Map and
>>> fix the getLevel() method ? or you prefer fix on your own ?
>>>
>>> Is it better to discuss the fix on the bug database (still not visible) ?
>>>
>>> Laurent
>>>
>>> 2013/3/19 Mandy Chung <mandy.ch...@oracle.com>
>>>
>>>> Hi Laurent,
>>>>
>>>> Thanks for the contribution. I agree that the map can be replaced with
>>>> a direct mapping from a int value to Level object and avoid the autoboxing
>>>> conversion.
>>>>
>>>> I have filed a bug to track this and target this for JDK8:
>>>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id= 8010309
>>>>
>>>> Thanks
>>>> Mandy
>>>>
>>>>
>>>> On 3/19/13 5:19 AM, Laurent Bourgès wrote:
>>>>
>>>> Dear all,
>>>>
>>>> I run recently netbeans profiler on my swing application
>>>> (Aspro2:http://www.jmmc.fr/aspro
>>>> ) under linux x64 platform and figured out a
>>>> performance and waste issue related to PlatformLogger.
>>>>
>>>> Actually, the JavaLogger implementation uses a Map<Integer, Object>
>>>> levelObjects to store mapping between PlatformLogger's levels (int) and JUL
>>>> Level instances.
>>>>
>>>> However, the isLoggable(int level) method is highly used by awt project and
>>>> other JDK projects and it leads to many Integer allocations as autoboxing
>>>> converts the level as int to an Integer instance used by the Map.get()
>>>> call.
>>>>
>>>> /**
>>>> * JavaLogger forwards all the calls to its corresponding
>>>> * java.util.logging.Logger object.
>>>> */
>>>> static class JavaLogger extends LoggerProxy {
>>>> private static final* Map<Integer, Object>* levelObjects = new
>>>> HashMap<>();
>>>> ...
>>>> public boolean isLoggable(*int level*) {
>>>> return LoggingSupport.isLoggable(javaLogger, *
>>>> levelObjects.get(level)*);
>>>> }
>>>> }
>>>>
>>>> I wrote a simple test to illustrate that performance / waste problem:
>>>> PlatformLoggerTest that simply performs 1 million DISABLED log statements:
>>>> if (log.isLoggable(PlatformLogger.FINEST)) {
>>>> log.finest("test PlatformLogger.FINEST");
>>>> }
>>>>
>>>> As you can see in screenshots:
>>>> - 5 million Integer instances are allocated
>>>> - Integer.valueOf(int) is called 5 million times (autoboxing)
>>>> - HashMap.get() represents 30% of the test time
>>>> - patched PlatformLogger is 3x times faster
>>>> [jvm options: -Xms8m -Xmx8m -verbose:gc]
>>>>
>>>> I suggest you to use an alternative way to map PlatformLogger's levels
>>>> (int) and JUL Level instances to fix that performance / memory issue: I
>>>> added the getLevel(int level) method that performs a switch case to return
>>>> the corresponding Level object (quick and dirty solution).
>>>>
>>>> I advocate this is not a very clean solution but I prefer efficiency here:
>>>> any better solution may be appropriate to avoid at least Integer allocation
>>>> and maybe enhance performance.
>>>>
>>>> Best regards,
>>>> Laurent Bourgès
>>>>
>>>> PS: here is the patch as text:
>>>>
>>>> # This patch file was generated by NetBeans IDE
>>>> # It uses platform neutral UTF-8 encoding and \n newlines.
>>>> --- PlatformLogger.java (6767)
>>>> +++ PlatformLogger.java (6768)
>>>> @@ -468,31 +468,13 @@
>>>> * java.util.logging.Logger object.
>>>> */
>>>> static class JavaLogger extends LoggerProxy {
>>>> - /** Note: using Integer keys leads to a lot of new Integer
>>>> instances !! */
>>>> - private static final Map<Integer, Object> levelObjects = new
>>>> HashMap<>();
>>>> - /** fastest mapping to Level instances from PlatformLogger level
>>>> as integer */
>>>> - private static final Object[] fastLevelObjects;
>>>> -
>>>> -
>>>> + private static final Map<Integer, Object> levelObjects =
>>>> + new HashMap<>();
>>>> +
>>>> static {
>>>> if (LoggingSupport.isAvailable()) {
>>>> // initialize the map to Level objects
>>>> getLevelObjects();
>>>> -
>>>> - // initialize the fastLevelObjects:
>>>> - fastLevelObjects = new Object[] {
>>>> - LoggingSupport.parseLevel(getLevelName(OFF)), //
>>>> 0
>>>> - LoggingSupport.parseLevel(getLevelName(SEVERE)), //
>>>> 1
>>>> - LoggingSupport.parseLevel(getLevelName(WARNING)), //
>>>> 2
>>>> - LoggingSupport.parseLevel(getLevelName(INFO)), //
>>>> 3
>>>> - LoggingSupport.parseLevel(getLevelName(CONFIG)), //
>>>> 4
>>>> - LoggingSupport.parseLevel(getLevelName(FINE)), //
>>>> 5
>>>> - LoggingSupport.parseLevel(getLevelName(FINER)), //
>>>> 6
>>>> - LoggingSupport.parseLevel(getLevelName(FINEST)), //
>>>> 7
>>>> - LoggingSupport.parseLevel(getLevelName(ALL)) //
>>>> 8
>>>> - };
>>>> - } else {
>>>> - fastLevelObjects = null; // check null
>>>> }
>>>> }
>>>>
>>>> @@ -515,7 +497,7 @@
>>>> this.javaLogger = LoggingSupport.getLogger(name);
>>>> if (level != 0) {
>>>> // level has been updated and so set the Logger's level
>>>> - LoggingSupport.setLevel(javaLogger, getLevel(level));
>>>> + LoggingSupport.setLevel(javaLogger,
>>>> levelObjects.get(level));
>>>> }
>>>> }
>>>>
>>>> @@ -526,11 +508,11 @@
>>>> * not be updated.
>>>> */
>>>> void doLog(int level, String msg) {
>>>> - LoggingSupport.log(javaLogger, getLevel(level), msg);
>>>> + LoggingSupport.log(javaLogger, levelObjects.get(level), msg);
>>>> }
>>>>
>>>> void doLog(int level, String msg, Throwable t) {
>>>> - LoggingSupport.log(javaLogger, getLevel(level), msg, t);
>>>> + LoggingSupport.log(javaLogger, levelObjects.get(level), msg,
>>>> t);
>>>> }
>>>>
>>>> void doLog(int level, String msg, Object... params) {
>>>> @@ -544,12 +526,12 @@
>>>> for (int i = 0; i < len; i++) {
>>>> sparams [i] = String.valueOf(params[i]);
>>>> }
>>>> - LoggingSupport.log(javaLogger, getLevel(level), msg, sparams);
>>>> + LoggingSupport.log(javaLogger, levelObjects.get(level), msg,
>>>> sparams);
>>>> }
>>>>
>>>> boolean isEnabled() {
>>>> Object level = LoggingSupport.getLevel(javaLogger);
>>>> - return level == null || level.equals(getLevel(OFF)) == false;
>>>> + return level == null || level.equals(levelObjects.get(OFF)) ==
>>>> false;
>>>> }
>>>>
>>>> int getLevel() {
>>>> @@ -566,34 +548,12 @@
>>>>
>>>> void setLevel(int newLevel) {
>>>> levelValue = newLevel;
>>>> - LoggingSupport.setLevel(javaLogger, getLevel(newLevel));
>>>> + LoggingSupport.setLevel(javaLogger,
>>>> levelObjects.get(newLevel));
>>>> }
>>>>
>>>> public boolean isLoggable(int level) {
>>>> - return LoggingSupport.isLoggable(javaLogger, getLevel(level));
>>>> + return LoggingSupport.isLoggable(javaLogger,
>>>> levelObjects.get(level));
>>>> }
>>>> -
>>>> - /**
>>>> - * Return the corresponding level object (fastest implementation)
>>>> - * @param level PlatformLogger level as primitive integer
>>>> - * @return Object (JUL Level instance)
>>>> - */
>>>> - private static Object getLevel(final int level) {
>>>> - // higher occurences first (finest, fine, finer, info):
>>>> - switch (level) {
>>>> - case FINEST : return fastLevelObjects[7];
>>>> - case FINE : return fastLevelObjects[5];
>>>> - case FINER : return fastLevelObjects[6];
>>>> - case INFO : return fastLevelObjects[3];
>>>> - case CONFIG : return fastLevelObjects[4];
>>>> - case WARNING : return fastLevelObjects[2];
>>>> - case SEVERE : return fastLevelObjects[1];
>>>> - case ALL : return fastLevelObjects[8];
>>>> - case OFF : return fastLevelObjects[0];
>>>> - default : return null;
>>>> - }
>>>> - }
>>>> -
>>>> }
>>>>
>>>> private static String getLevelName(int level) {
>>>>
>>>>
>>>>
>>>
>>>
>>
>
