Package org.apache.sis.util.logging

Class LoggerAdapter

Object
Logger
LoggerAdapter
public abstract class LoggerAdapter extends Logger
An adapter that redirect all JDK logging events to an other logging framework. This class redefines the severe, warning, info, config, fine, finer and finest methods as abstract ones. Subclasses should implement those methods in order to map JDK logging levels to the backend logging framework.

All log methods are overridden in order to redirect to one of the above-cited methods. Note that this is the opposite approach than the JDK logging framework one, which implements everything on top of Logger​.log(Log­Record). This adapter is defined in terms of severe … finest methods instead because external frameworks like Commons-logging don't work with Log­Record, and sometime provides nothing else than convenience methods equivalent to severe … finest.

Restrictions

Because the configuration is expected to be fully controlled by the external logging framework, every configuration methods inherited from Logger are disabled:
  • add­Handler(Handler) since the handling is performed by the external framework.
  • set­Use­Parent­Handlers(boolean) since this adapter never delegates to the parent handlers. This is consistent with the previous item and avoid mixing loggings from the external framework with JDK loggings.
  • set­Parent(Logger) since this adapter should not inherits any configuration from a parent logger using the JDK logging framework.
  • set­Filter(Filter) for keeping this Logger­Adapter simple.
Since Logger­Adapters do not hold any configuration by themselves, it is not strictly necessary to add them to the log manager. The adapters can be created, garbage-collected and recreated again while preserving their behavior since their configuration is entirely contained in the external logging framework.

Localization

This logger is always created without resource bundles. Localizations shall be done through explicit calls to logrb or log(Log­Record) methods. This is sufficient for SIS needs, which performs all localizations through the later. Note that those methods will be slower in this Logger­Adapter than the default Logger because this adapter localizes and formats records immediately instead of letting the Handler performs this work only if needed.

Logging levels

If a log record level is not one of the predefined ones, then this class maps to the first level below the specified one. For example if a log record has some level between FINE and FINER, then the finer method will be invoked. See is­Loggable(Level) for implementation tips taking advantage of this rule.
Since:
0.3
See Also:

Defined in the sis-utility module

  • Constructor Details

    • LoggerAdapter

      protected LoggerAdapter(String name)
      Creates a new logger.
      Parameters:
      name - the logger name.

  • Method Details

    • setLevel

      public abstract void setLevel(Level level)
      Sets the level for this logger. Subclasses must redirect the call to the external logging framework, or do nothing if the level can not be changed programmatically.
      Overrides:
      set­Level in class Logger
      Parameters:
      level - the new value for the log level (may be null).

    • getLevel

      public abstract Level getLevel()
      Returns the level for this logger. Subclasses shall get this level from the external logging framework.
      Overrides:
      get­Level in class Logger
      Returns:
      the logger's level.

    • getDebugLevel

      @Debug protected Level getDebugLevel()
      Returns the level for entering(…), exiting(…) and throwing(…) methods. The default implementation returns Level​.FINER, which is consistent with the value used in the JDK logging framework. Subclasses should override this method if a different debug level is wanted.
      Returns:
      the level to use for debugging information.

    • isLoggable

      public abstract boolean isLoggable(Level level)
      Returns true if the specified level is loggable.

      Implementation tip

      Given that Level​.int­Value() for all predefined levels are documented in the Level specification and are multiple of 100, given that integer divisions are rounded toward zero and given rule documented in this class javadoc, then logging levels can be efficiently mapped to predefined levels using switch statements as below. This statement has good chances to be compiled to the tableswitch bytecode rather than lookupswitch (see Compiling Switches in The Java Virtual Machine Specification). 
      public boolean isLoggable(Level level) {
    final int n = level.intValue();
    switch (n / 100) {
        default: {
            // MAX_VALUE is a special value for Level.OFF. Otherwise and
            // if positive, fallthrough since we are greater than SEVERE.
            switch (n) {
                case Integer.MIN_VALUE: return true;  // Level.ALL
                case Integer.MAX_VALUE: return false; // Level.OFF
                default: if (n < 0) return false;
            }
        }
        case 10: return isSevereEnabled();
        case  9: return isWarningEnabled();
        case  8: return isInfoEnabled();
        case  7: return isConfigEnabled();
        case  6: // fallthrough
        case  5: return isFineEnabled();
        case  4: return isFinerEnabled();
        case  3: return isFinestEnabled();
        case  2: // fallthrough
        case  1: // fallthrough
        case  0: return false;
    }
}
      Overrides:
      is­Loggable in class Logger
      Parameters:
      level - a message logging level.
      Returns:
      true if the given message level is currently being logged.

    • severe

      public abstract void severe(String message)
      Logs a SEVERE message.
      Overrides:
      severe in class Logger
      Parameters:
      message - the message to log.

    • warning

      public abstract void warning(String message)
      Logs a WARNING message.
      Overrides:
      warning in class Logger
      Parameters:
      message - the message to log.

    • info

      public abstract void info(String message)
      Logs an INFO message.
      Overrides:
      info in class Logger
      Parameters:
      message - the message to log.

    • config

      public abstract void config(String message)
      Logs an CONFIG message.
      Overrides:
      config in class Logger
      Parameters:
      message - the message to log.

    • fine

      public abstract void fine(String message)
      Logs a FINE message.
      Overrides:
      fine in class Logger
      Parameters:
      message - the message to log.

    • finer

      public abstract void finer(String message)
      Logs a FINER message.
      Overrides:
      finer in class Logger
      Parameters:
      message - the message to log.

    • finest

      public abstract void finest(String message)
      Logs a FINEST message.
      Overrides:
      finest in class Logger
      Parameters:
      message - the message to log.

    • entering

      public void entering(String sourceClass, String sourceMethod)
      Logs a method entry to the debug level. Compared to the default Logger, this implementation bypass the level check in order to let the backing logging framework do its own check.
      Overrides:
      entering in class Logger
      Parameters:
      source­Class - name of class that issued the logging request.
      source­Method - name of method that is being entered.

    • entering

      public void entering(String sourceClass, String sourceMethod, Object param)
      Logs a method entry to the debug level with one parameter. Compared to the default Logger, this implementation bypass the level check in order to let the backing logging framework do its own check.
      Overrides:
      entering in class Logger
      Parameters:
      source­Class - name of class that issued the logging request.
      source­Method - name of method that is being entered.
      param - parameter to the method being entered.

    • entering

      public void entering(String sourceClass, String sourceMethod, Object[] params)
      Logs a method entry to the debug level with many parameters. Compared to the default Logger, this implementation bypass the level check in order to let the backing logging framework do its own check.
      Overrides:
      entering in class Logger
      Parameters:
      source­Class - name of class that issued the logging request.
      source­Method - name of method that is being entered.
      params - array of parameters to the method being entered.

    • exiting

      public void exiting(String sourceClass, String sourceMethod)
      Logs a method return to the debug level. Compared to the default Logger, this implementation bypass the level check in order to let the backing logging framework do its own check.
      Overrides:
      exiting in class Logger
      Parameters:
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.

    • exiting

      public void exiting(String sourceClass, String sourceMethod, Object result)
      Logs a method return to the debug level. Compared to the default Logger, this implementation bypass the level check in order to let the backing logging framework do its own check.
      Overrides:
      exiting in class Logger
      Parameters:
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      result - object that is being returned.

    • throwing

      public void throwing(String sourceClass, String sourceMethod, Throwable thrown)
      Logs a method failure to the debug level. Compared to the default Logger, this implementation bypass the level check in order to let the backing logging framework do its own check.
      Overrides:
      throwing in class Logger
      Parameters:
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      thrown - the Throwable that is being thrown.

    • log

      public void log(LogRecord record)
      Logs a record. The default implementation delegates to one of the logrb or logp(Level,String,String,String) methods.
      Overrides:
      log in class Logger
      Parameters:
      record - the log record to be published.

    • log

      public void log(Level level, String message)
      Logs a record at the specified level. The default implementation delegates to one of the severe, warning, info, config, fine, finer or finest methods according the supplied level.
      Overrides:
      log in class Logger
      Parameters:
      level - one of the message level identifiers.
      message - the message to log.

    • log

      public void log(Level level, String message, Throwable thrown)
      Logs a record at the specified level. The default implementation discards the exception and delegates to log(level, message).
      Overrides:
      log in class Logger
      Parameters:
      level - one of the message level identifiers.
      message - the message to log.
      thrown - throwable associated with log message.

    • log

      public void log(Level level, String message, Object param)
      Logs a record at the specified level. The default implementation delegates to log(level, message, params) where the params array is built from the param object.
      Overrides:
      log in class Logger
      Parameters:
      level - one of the message level identifiers.
      message - the message to log.
      param - parameter to the method being entered.

    • log

      public void log(Level level, String message, Object[] params)
      Logs a record at the specified level. The default implementation formats the message immediately, then delegates to log(level, message).
      Overrides:
      log in class Logger
      Parameters:
      level - one of the message level identifiers.
      message - the message to log.
      params - array of parameters to the method being entered.

    • logp

      public void logp(Level level, String sourceClass, String sourceMethod, String message)
      Logs a record at the specified level. The default implementation discards the source class and source method, then delegates to log(level, message).
      Overrides:
      logp in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      message - the message to log.

    • logp

      public void logp(Level level, String sourceClass, String sourceMethod, String message, Throwable thrown)
      Logs a record at the specified level. The default implementation discards the source class and source method, then delegates to log(level, message, thrown).
      Overrides:
      logp in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      message - the message to log.
      thrown - throwable associated with log message.

    • logp

      public void logp(Level level, String sourceClass, String sourceMethod, String message, Object param)
      Logs a record at the specified level. The default implementation delegates to logp(level, source­Class, source­Method, message, params) where the params array is built from the param object.

      Note that source­Class and source­Method will be discarded unless the target logp method has been overridden.

      Overrides:
      logp in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      message - the message to log.
      param - parameter to the method being entered.

    • logp

      public void logp(Level level, String sourceClass, String sourceMethod, String message, Object[] params)
      Logs a record at the specified level. The default implementation formats the message immediately, then delegates to logp(level, source­Class, source­Method, message).

      Note that source­Class and source­Method will be discarded unless the target logp method has been overridden.

      Overrides:
      logp in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      message - the message to log.
      params - array of parameters to the method being entered.

    • logrb

      public void logrb(Level level, String sourceClass, String sourceMethod, ResourceBundle bundle, String message, Object... params)
      Logs a localizable record at the specified level. The default implementation localizes the message immediately, then delegates to logp(level, source­Class, source­Method, message, params).
      Overrides:
      logrb in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      bundle - the resource bundle for localizing the message, or null.
      message - the message to log.
      params - array of parameters to the method being entered.
      Since:
      0.5

    • logrb

      public void logrb(Level level, String sourceClass, String sourceMethod, ResourceBundle bundle, String message, Throwable thrown)
      Logs a localizable record at the specified level. The default implementation localizes the message immediately, then delegates to logp(level, source­Class, source­Method, message, thrown).
      Overrides:
      logrb in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      bundle - the resource bundle for localizing the message, or null.
      message - the message to log.
      thrown - throwable associated with log message.
      Since:
      0.5

    • logrb

      @Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String message)
      Deprecated.
      JDK 8 has deprecated this method.
      Logs a localizable record at the specified level. The default implementation localizes the message immediately, then delegates to logp(level, source­Class, source­Method, message).
      Overrides:
      logrb in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      bundle­Name - name of resource bundle to localize message, or null.
      message - the message to log.

    • logrb

      @Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String message, Throwable thrown)
      Deprecated.
      JDK 8 has deprecated this method.
      Logs a localizable record at the specified level. The default implementation localizes the message immediately, then delegates to logp(level, source­Class, source­Method, message, thrown).
      Overrides:
      logrb in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      bundle­Name - name of resource bundle to localize message, or null.
      message - the message to log.
      thrown - throwable associated with log message.

    • logrb

      @Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String message, Object param)
      Deprecated.
      JDK 8 has deprecated this method.
      Logs a localizable record at the specified level. The default implementation localizes the message immediately, then delegates to logp(level, source­Class, source­Method, message, param).
      Overrides:
      logrb in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      bundle­Name - name of resource bundle to localize message, or null.
      message - the message to log.
      param - parameter to the method being entered.

    • logrb

      @Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String message, Object[] params)
      Deprecated.
      JDK 8 has deprecated this method.
      Logs a localizable record at the specified level. The default implementation localizes the message immediately, then delegates to logp(level, source­Class, source­Method, message, params).
      Overrides:
      logrb in class Logger
      Parameters:
      level - one of the message level identifiers.
      source­Class - name of class that issued the logging request.
      source­Method - name of the method.
      bundle­Name - name of resource bundle to localize message, or null.
      message - the message to log.
      params - array of parameters to the method being entered.

    • addHandler

      public void addHandler(Handler handler)
      Do nothing since this logger adapter does not supports handlers. The configuration should be fully controlled by the external logging framework (e.g. Commons-logging) instead, which is not expected to use Handler objects.
      Overrides:
      add­Handler in class Logger
      Parameters:
      handler - a logging handler, ignored in default implementation.

    • removeHandler

      public void removeHandler(Handler handler)
      Do nothing since this logger adapter does not support handlers.
      Overrides:
      remove­Handler in class Logger
      Parameters:
      handler - a logging handler, ignored in default implementation.

    • setUseParentHandlers

      public void setUseParentHandlers(boolean useParentHandlers)
      Do nothing since this logger never use parent handlers. This is consistent with add­Handler(java​.util​.logging​.Handler) not allowing to add any handlers, and avoid mixing loggings from the external framework with JDK loggings.
      Overrides:
      set­Use­Parent­Handlers in class Logger
      Parameters:
      use­Parent­Handlers - ignored in default implementation.

    • setParent

      public void setParent(Logger parent)
      Do nothing since this logger adapter does not support arbitrary parents. More specifically, it should not inherits any configuration from a parent logger using the JDK logging framework.
      Overrides:
      set­Parent in class Logger
      Parameters:
      parent - ignored in default implementation.

    • setFilter

      public void setFilter(Filter filter)
      Do nothing since this logger adapter does not support filters. It is difficult to query efficiently the filter in this Logger­Adapter architecture (e.g. we would need to make sure that Filter​.is­Loggable(java​.util​.logging​.Log­Record) is invoked only once even if a log call is cascaded into many other log calls, and this test must works in multi-threads environment).
      Overrides:
      set­Filter in class Logger
      Parameters:
      filter - ignored in default implementation.