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   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
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   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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  package java.util.logging;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.ResourceBundle;
  
  /**
   * The Level class defines a set of standard logging levels that
   * can be used to control logging output.  The logging Level objects
   * are ordered and are specified by ordered integers.  Enabling logging
   * at a given level also enables logging at all higher levels.
   * <p>
   * Clients should normally use the predefined Level constants such
   * as Level.SEVERE.
   * <p>
   * The levels in descending order are:
   * <ul>
   * <li>SEVERE (highest value)
   * <li>WARNING
   * <li>INFO
   * <li>CONFIG
   * <li>FINE
   * <li>FINER
   * <li>FINEST  (lowest value)
   * </ul>
   * In addition there is a level OFF that can be used to turn
   * off logging, and a level ALL that can be used to enable
   * logging of all messages.
   * <p>
   * It is possible for third parties to define additional logging
   * levels by subclassing Level.  In such cases subclasses should
   * take care to chose unique integer level values and to ensure that
   * they maintain the Object uniqueness property across serialization
   * by defining a suitable readResolve method.
   *
   * @since 1.4
   */
  
  public class Level implements java.io.Serializable {
      private static final String defaultBundle = "sun.util.logging.resources.logging";
  
      /**
       * @serial  The non-localized name of the level.
       */
      private final String name;
  
      /**
       * @serial  The integer value of the level.
       */
      private final int value;
  
      /**
       * @serial The resource bundle name to be used in localizing the level name.
       */
      private final String resourceBundleName;
  
      // localized level name
      private transient String localizedLevelName;
      private transient Locale cachedLocale;
  
      /**
       * OFF is a special level that can be used to turn off logging.
       * This level is initialized to <CODE>Integer.MAX_VALUE</CODE>.
       */
      public static final Level OFF = new Level("OFF",Integer.MAX_VALUE, defaultBundle);
  
      /**
       * SEVERE is a message level indicating a serious failure.
       * <p>
       * In general SEVERE messages should describe events that are
       * of considerable importance and which will prevent normal
       * program execution.   They should be reasonably intelligible
       * to end users and to system administrators.
       * This level is initialized to <CODE>1000</CODE>.
       */
      public static final Level SEVERE = new Level("SEVERE",1000, defaultBundle);
  
      /**
       * WARNING is a message level indicating a potential problem.
       * <p>
       * In general WARNING messages should describe events that will
       * be of interest to end users or system managers, or which
       * indicate potential problems.
       * This level is initialized to <CODE>900</CODE>.
       */
      public static final Level WARNING = new Level("WARNING", 900, defaultBundle);
  
      /**
       * INFO is a message level for informational messages.
       * <p>
       * Typically INFO messages will be written to the console
       * or its equivalent.  So the INFO level should only be
       * used for reasonably significant messages that will
       * make sense to end users and system administrators.
       * This level is initialized to <CODE>800</CODE>.
       */
      public static final Level INFO = new Level("INFO", 800, defaultBundle);
  
      /**
       * CONFIG is a message level for static configuration messages.
       * <p>
       * CONFIG messages are intended to provide a variety of static
       * configuration information, to assist in debugging problems
       * that may be associated with particular configurations.
       * For example, CONFIG message might include the CPU type,
       * the graphics depth, the GUI look-and-feel, etc.
       * This level is initialized to <CODE>700</CODE>.
       */
      public static final Level CONFIG = new Level("CONFIG", 700, defaultBundle);
  
      /**
       * FINE is a message level providing tracing information.
       * <p>
       * All of FINE, FINER, and FINEST are intended for relatively
       * detailed tracing.  The exact meaning of the three levels will
       * vary between subsystems, but in general, FINEST should be used
       * for the most voluminous detailed output, FINER for somewhat
       * less detailed output, and FINE for the  lowest volume (and
       * most important) messages.
       * <p>
       * In general the FINE level should be used for information
       * that will be broadly interesting to developers who do not have
       * a specialized interest in the specific subsystem.
       * <p>
       * FINE messages might include things like minor (recoverable)
       * failures.  Issues indicating potential performance problems
       * are also worth logging as FINE.
       * This level is initialized to <CODE>500</CODE>.
       */
      public static final Level FINE = new Level("FINE", 500, defaultBundle);
  
      /**
       * FINER indicates a fairly detailed tracing message.
       * By default logging calls for entering, returning, or throwing
       * an exception are traced at this level.
       * This level is initialized to <CODE>400</CODE>.
       */
      public static final Level FINER = new Level("FINER", 400, defaultBundle);
  
      /**
       * FINEST indicates a highly detailed tracing message.
       * This level is initialized to <CODE>300</CODE>.
       */
      public static final Level FINEST = new Level("FINEST", 300, defaultBundle);
  
      /**
       * ALL indicates that all messages should be logged.
       * This level is initialized to <CODE>Integer.MIN_VALUE</CODE>.
       */
      public static final Level ALL = new Level("ALL", Integer.MIN_VALUE, defaultBundle);
  
      /**
       * Create a named Level with a given integer value.
       * <p>
       * Note that this constructor is "protected" to allow subclassing.
       * In general clients of logging should use one of the constant Level
       * objects such as SEVERE or FINEST.  However, if clients need to
       * add new logging levels, they may subclass Level and define new
       * constants.
       * @param name  the name of the Level, for example "SEVERE".
       * @param value an integer value for the level.
       * @throws NullPointerException if the name is null
       */
      protected Level(String name, int value) {
          this(name, value, null);
      }
  
      /**
       * Create a named Level with a given integer value and a
       * given localization resource name.
       * <p>
       * @param name  the name of the Level, for example "SEVERE".
       * @param value an integer value for the level.
       * @param resourceBundleName name of a resource bundle to use in
       *    localizing the given name. If the resourceBundleName is null
       *    or an empty string, it is ignored.
       * @throws NullPointerException if the name is null
       */
      protected Level(String name, int value, String resourceBundleName) {
          this(name, value, resourceBundleName, true);
      }
  
      // private constructor to specify whether this instance should be added
      // to the KnownLevel list from which Level.parse method does its look up
      private Level(String name, int value, String resourceBundleName, boolean visible) {
          if (name == null) {
              throw new NullPointerException();
          }
          this.name = name;
          this.value = value;
          this.resourceBundleName = resourceBundleName;
          this.localizedLevelName = resourceBundleName == null ? name : null;
          this.cachedLocale = null;
          if (visible) {
              KnownLevel.add(this);
          }
      }
  
      /**
       * Return the level's localization resource bundle name, or
       * null if no localization bundle is defined.
       *
       * @return localization resource bundle name
       */
      public String getResourceBundleName() {
          return resourceBundleName;
      }
  
      /**
       * Return the non-localized string name of the Level.
       *
       * @return non-localized name
       */
      public String getName() {
          return name;
      }
  
      /**
       * Return the localized string name of the Level, for
       * the current default locale.
       * <p>
       * If no localization information is available, the
       * non-localized name is returned.
       *
       * @return localized name
       */
      public String getLocalizedName() {
          return getLocalizedLevelName();
      }
  
      // package-private getLevelName() is used by the implementation
      // instead of getName() to avoid calling the subclass's version
      final String getLevelName() {
          return this.name;
      }
  
      private String computeLocalizedLevelName(Locale newLocale) {
          // Android-changed: Use Thread.currentThread().getContextClassLoader().
          // Otherwise, we might get a BootClassLoader.
          // ResourceBundle rb = ResourceBundle.getBundle(resourceBundleName, newLocale);
          ResourceBundle rb = ResourceBundle.getBundle(resourceBundleName, newLocale,
                                                       Thread.currentThread().getContextClassLoader());
          final String localizedName = rb.getString(name);
  
          final boolean isDefaultBundle = defaultBundle.equals(resourceBundleName);
          if (!isDefaultBundle) return localizedName;
  
          // This is a trick to determine whether the name has been translated
          // or not. If it has not been translated, we need to use Locale.ROOT
          // when calling toUpperCase().
          final Locale rbLocale = rb.getLocale();
          final Locale locale =
                  Locale.ROOT.equals(rbLocale)
                  || name.equals(localizedName.toUpperCase(Locale.ROOT))
                  ? Locale.ROOT : rbLocale;
  
          // ALL CAPS in a resource bundle's message indicates no translation
          // needed per Oracle translation guideline.  To workaround this
          // in Oracle JDK implementation, convert the localized level name
          // to uppercase for compatibility reason.
          return Locale.ROOT.equals(locale) ? name : localizedName.toUpperCase(locale);
      }
  
      // Avoid looking up the localizedLevelName twice if we already
      // have it.
      final String getCachedLocalizedLevelName() {
  
          if (localizedLevelName != null) {
              if (cachedLocale != null) {
                  if (cachedLocale.equals(Locale.getDefault())) {
                      // OK: our cached value was looked up with the same
                      //     locale. We can use it.
                      return localizedLevelName;
                  }
              }
          }
  
          if (resourceBundleName == null) {
              // No resource bundle: just use the name.
              return name;
          }
  
          // We need to compute the localized name.
          // Either because it's the first time, or because our cached
          // value is for a different locale. Just return null.
          return null;
      }
  
      final synchronized String getLocalizedLevelName() {
  
          // See if we have a cached localized name
          final String cachedLocalizedName = getCachedLocalizedLevelName();
          if (cachedLocalizedName != null) {
              return cachedLocalizedName;
          }
  
          // No cached localized name or cache invalid.
          // Need to compute the localized name.
          final Locale newLocale = Locale.getDefault();
          try {
              localizedLevelName = computeLocalizedLevelName(newLocale);
          } catch (Exception ex) {
              localizedLevelName = name;
          }
          cachedLocale = newLocale;
          return localizedLevelName;
      }
  
      // Returns a mirrored Level object that matches the given name as
      // specified in the Level.parse method.  Returns null if not found.
      //
      // It returns the same Level object as the one returned by Level.parse
      // method if the given name is a non-localized name or integer.
      //
      // If the name is a localized name, findLevel and parse method may
      // return a different level value if there is a custom Level subclass
      // that overrides Level.getLocalizedName() to return a different string
      // than what's returned by the default implementation.
      //
      static Level findLevel(String name) {
          if (name == null) {
              throw new NullPointerException();
          }
  
          KnownLevel level;
  
          // Look for a known Level with the given non-localized name.
          level = KnownLevel.findByName(name);
          if (level != null) {
              return level.mirroredLevel;
          }
  
          // Now, check if the given name is an integer.  If so,
          // first look for a Level with the given value and then
          // if necessary create one.
          try {
              int x = Integer.parseInt(name);
              level = KnownLevel.findByValue(x);
              if (level == null) {
                  // add new Level
                  Level levelObject = new Level(name, x);
                  level = KnownLevel.findByValue(x);
              }
              return level.mirroredLevel;
          } catch (NumberFormatException ex) {
              // Not an integer.
              // Drop through.
          }
  
          level = KnownLevel.findByLocalizedLevelName(name);
          if (level != null) {
              return level.mirroredLevel;
          }
  
          return null;
      }
  
      /**
       * Returns a string representation of this Level.
       *
       * @return the non-localized name of the Level, for example "INFO".
       */
      @Override
      public final String toString() {
          return name;
      }
  
      /**
       * Get the integer value for this level.  This integer value
       * can be used for efficient ordering comparisons between
       * Level objects.
       * @return the integer value for this level.
       */
      public final int intValue() {
          return value;
      }
  
      private static final long serialVersionUID = -8176160795706313070L;
  
      // Serialization magic to prevent "doppelgangers".
      // This is a performance optimization.
      private Object readResolve() {
          KnownLevel o = KnownLevel.matches(this);
          if (o != null) {
              return o.levelObject;
          }
  
          // Woops.  Whoever sent us this object knows
          // about a new log level.  Add it to our list.
          Level level = new Level(this.name, this.value, this.resourceBundleName);
          return level;
      }
  
      /**
       * Parse a level name string into a Level.
       * <p>
       * The argument string may consist of either a level name
       * or an integer value.
       * <p>
       * For example:
       * <ul>
       * <li>     "SEVERE"
       * <li>     "1000"
       * </ul>
       *
       * @param  name   string to be parsed
       * @throws NullPointerException if the name is null
       * @throws IllegalArgumentException if the value is not valid.
       * Valid values are integers between <CODE>Integer.MIN_VALUE</CODE>
       * and <CODE>Integer.MAX_VALUE</CODE>, and all known level names.
       * Known names are the levels defined by this class (e.g., <CODE>FINE</CODE>,
       * <CODE>FINER</CODE>, <CODE>FINEST</CODE>), or created by this class with
       * appropriate package access, or new levels defined or created
       * by subclasses.
       *
       * @return The parsed value. Passing an integer that corresponds to a known name
       * (e.g., 700) will return the associated name (e.g., <CODE>CONFIG</CODE>).
       * Passing an integer that does not (e.g., 1) will return a new level name
       * initialized to that value.
       */
      public static synchronized Level parse(String name) throws IllegalArgumentException {
          // Check that name is not null.
          name.length();
  
          KnownLevel level;
  
          // Look for a known Level with the given non-localized name.
          level = KnownLevel.findByName(name);
          if (level != null) {
              return level.levelObject;
          }
  
          // Now, check if the given name is an integer.  If so,
          // first look for a Level with the given value and then
          // if necessary create one.
          try {
              int x = Integer.parseInt(name);
              level = KnownLevel.findByValue(x);
              if (level == null) {
                  // add new Level
                  Level levelObject = new Level(name, x);
                  level = KnownLevel.findByValue(x);
              }
              return level.levelObject;
          } catch (NumberFormatException ex) {
              // Not an integer.
              // Drop through.
          }
  
          // Finally, look for a known level with the given localized name,
          // in the current default locale.
          // This is relatively expensive, but not excessively so.
          level = KnownLevel.findByLocalizedLevelName(name);
          if (level != null) {
              return level.levelObject;
          }
  
          // OK, we've tried everything and failed
          throw new IllegalArgumentException("Bad level \"" + name + "\"");
      }
  
      /**
       * Compare two objects for value equality.
       * @return true if and only if the two objects have the same level value.
       */
      @Override
      public boolean equals(Object ox) {
          try {
              Level lx = (Level)ox;
              return (lx.value == this.value);
          } catch (Exception ex) {
              return false;
          }
      }
  
      /**
       * Generate a hashcode.
       * @return a hashcode based on the level value
       */
      @Override
      public int hashCode() {
          return this.value;
      }
  
      // KnownLevel class maintains the global list of all known levels.
      // The API allows multiple custom Level instances of the same name/value
      // be created. This class provides convenient methods to find a level
      // by a given name, by a given value, or by a given localized name.
      //
      // KnownLevel wraps the following Level objects:
      // 1. levelObject:   standard Level object or custom Level object
      // 2. mirroredLevel: Level object representing the level specified in the
      //                   logging configuration.
      //
      // Level.getName, Level.getLocalizedName, Level.getResourceBundleName methods
      // are non-final but the name and resource bundle name are parameters to
      // the Level constructor.  Use the mirroredLevel object instead of the
      // levelObject to prevent the logging framework to execute foreign code
      // implemented by untrusted Level subclass.
      //
      // Implementation Notes:
      // If Level.getName, Level.getLocalizedName, Level.getResourceBundleName methods
      // were final, the following KnownLevel implementation can be removed.
      // Future API change should take this into consideration.
      static final class KnownLevel {
          private static Map<String, List<KnownLevel>> nameToLevels = new HashMap<>();
          private static Map<Integer, List<KnownLevel>> intToLevels = new HashMap<>();
          final Level levelObject;     // instance of Level class or Level subclass
          final Level mirroredLevel;   // mirror of the custom Level
          KnownLevel(Level l) {
              this.levelObject = l;
              if (l.getClass() == Level.class) {
                  this.mirroredLevel = l;
              } else {
                  // this mirrored level object is hidden
                  this.mirroredLevel = new Level(l.name, l.value, l.resourceBundleName, false);
              }
          }
  
          static synchronized void add(Level l) {
              // the mirroredLevel object is always added to the list
              // before the custom Level instance
              KnownLevel o = new KnownLevel(l);
              List<KnownLevel> list = nameToLevels.get(l.name);
              if (list == null) {
                  list = new ArrayList<>();
                  nameToLevels.put(l.name, list);
              }
              list.add(o);
  
              list = intToLevels.get(l.value);
              if (list == null) {
                  list = new ArrayList<>();
                  intToLevels.put(l.value, list);
              }
              list.add(o);
          }
  
          // Returns a KnownLevel with the given non-localized name.
          static synchronized KnownLevel findByName(String name) {
              List<KnownLevel> list = nameToLevels.get(name);
              if (list != null) {
                  return list.get(0);
              }
              return null;
          }
  
          // Returns a KnownLevel with the given value.
          static synchronized KnownLevel findByValue(int value) {
              List<KnownLevel> list = intToLevels.get(value);
              if (list != null) {
                  return list.get(0);
              }
              return null;
          }
  
          // Returns a KnownLevel with the given localized name matching
          // by calling the Level.getLocalizedLevelName() method (i.e. found
          // from the resourceBundle associated with the Level object).
          // This method does not call Level.getLocalizedName() that may
          // be overridden in a subclass implementation
          static synchronized KnownLevel findByLocalizedLevelName(String name) {
              for (List<KnownLevel> levels : nameToLevels.values()) {
                  for (KnownLevel l : levels) {
                      String lname = l.levelObject.getLocalizedLevelName();
                      if (name.equals(lname)) {
                          return l;
                      }
                  }
              }
              return null;
          }
  
          static synchronized KnownLevel matches(Level l) {
              List<KnownLevel> list = nameToLevels.get(l.name);
              if (list != null) {
                  for (KnownLevel level : list) {
                      Level other = level.mirroredLevel;
                      Class<? extends Level> type = level.levelObject.getClass();
                      if (l.value == other.value &&
                             (l.resourceBundleName == other.resourceBundleName ||
                                 (l.resourceBundleName != null &&
                                  l.resourceBundleName.equals(other.resourceBundleName)))) {
                          if (type == l.getClass()) {
                              return level;
                          }
                      }
                  }
              }
              return null;
          }
      }
  
  }
  