Interface Logger

  • All Known Implementing Classes:
    AbstractLogger, DefaultLogger, Log4JLogger, SLF4JLogger, SunLogger

    public interface Logger
    Abstract mechanism for dealing with logs from various objects. Implementations are expected to have a constructor that takes a single String representing the name of the logging item, or an empty constructor.
    See Also:
    LoggerFactory
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void debug​(java.lang.Object message)
      Log a message at debug level.
      void debug​(java.lang.Object message, java.lang.Throwable exception)
      Log a message at debug level.
      void debug​(java.lang.String message, java.lang.Object... args)
      Log a formatted message at debug level.
      void error​(java.lang.Object message)
      Log a message at error level.
      void error​(java.lang.Object message, java.lang.Throwable exception)
      Log a message at error level.
      void error​(java.lang.String message, java.lang.Object... args)
      Log a formatted message at debug level.
      void fatal​(java.lang.Object message)
      Log a message at fatal level.
      void fatal​(java.lang.Object message, java.lang.Throwable exception)
      Log a message at fatal level.
      void fatal​(java.lang.String message, java.lang.Object... args)
      Log a formatted message at debug level.
      java.lang.String getName()
      Get the name of this logger.
      void info​(java.lang.Object message)
      Log a message at info level.
      void info​(java.lang.Object message, java.lang.Throwable exception)
      Log a message at info level.
      void info​(java.lang.String message, java.lang.Object... args)
      Log a formatted message at info level.
      boolean isDebugEnabled()
      Checks whether DEBUG logging is enabled.
      boolean isInfoEnabled()
      Checks whether INFO logging is enabled.
      boolean isTraceEnabled()
      Checks whether TRACE logging is enabled.
      void log​(Level level, java.lang.Object message)
      Log a message at the specified level.
      void log​(Level level, java.lang.Object message, java.lang.Throwable exception)
      Log a message at the specified level.
      void trace​(java.lang.Object message)
      Log a message at trace level.
      void trace​(java.lang.Object message, java.lang.Throwable exception)
      Log a message at trace level.
      void trace​(java.lang.String message, java.lang.Object... args)
      Log a formatted message at trace level.
      void warn​(java.lang.Object message)
      Log a message at warning level.
      void warn​(java.lang.Object message, java.lang.Throwable exception)
      Log a message at warning level.
      void warn​(java.lang.String message, java.lang.Object... args)
      Log a formatted message at debug level.
    • Method Detail

      • getName

        java.lang.String getName()
        Get the name of this logger.
      • isDebugEnabled

        boolean isDebugEnabled()
        Checks whether DEBUG logging is enabled. This may return true, even when the logger is configured to not put the resulting output anywhere. You can use this method to avoid potential expensive (debugging) code when there is no need for it since it will be dropped anyway:
        
        if (log.isDebugEnabled()) {
          ... expensive code here ...
          log.debug(result);
        }
         
        Returns:
        true if debug messages would be displayed.
      • isInfoEnabled

        boolean isInfoEnabled()
        Checks whether INFO logging is enabled. This may return true, even when the logger is configured to not put the resulting output anywhere. You can use this method to avoid potential expensive (debugging) code when there is no need for it since it will be dropped anyway:
        
        if (log.isInfoEnabled()) {
          ... expensive code here ...
          log.info(result);
        }
         
        Returns:
        true if info messages would be displayed.
      • isTraceEnabled

        boolean isTraceEnabled()
        Checks whether TRACE logging is enabled. This may return true, even when the logger is configured to not put the resulting output anywhere. You can use this method to avoid potential expensive (debugging) code when there is no need for it since it will be dropped anyway:
        
        if (log.isTraceEnabled()) {
          ... expensive code here ...
          log.trace(result);
        }
         
        Returns:
        true if trace messages would be displayed.
      • log

        void log​(Level level,
                 java.lang.Object message,
                 java.lang.Throwable exception)
        Log a message at the specified level.
        Parameters:
        level - the level at which to log
        message - the message to log
        exception - an exception that caused the message
      • log

        void log​(Level level,
                 java.lang.Object message)
        Log a message at the specified level.
        Parameters:
        level - the level at which to log
        message - the message to log
      • trace

        void trace​(java.lang.Object message,
                   java.lang.Throwable exception)
        Log a message at trace level.
        Parameters:
        message - the message to log
        exception - the exception that caused the message to be generated
      • trace

        void trace​(java.lang.Object message)
        Log a message at trace level.
        Parameters:
        message - the message to log
      • trace

        void trace​(java.lang.String message,
                   java.lang.Object... args)
        Log a formatted message at trace level.
        Parameters:
        message - the message to log
        args - the arguments for that message
      • debug

        void debug​(java.lang.Object message,
                   java.lang.Throwable exception)
        Log a message at debug level.
        Parameters:
        message - the message to log
        exception - the exception that caused the message to be generated
      • debug

        void debug​(java.lang.Object message)
        Log a message at debug level.
        Parameters:
        message - the message to log
      • debug

        void debug​(java.lang.String message,
                   java.lang.Object... args)
        Log a formatted message at debug level.
        Parameters:
        message - the message to log
        args - the arguments for that message
      • info

        void info​(java.lang.Object message,
                  java.lang.Throwable exception)
        Log a message at info level.
        Parameters:
        message - the message to log
        exception - the exception that caused the message to be generated
      • info

        void info​(java.lang.Object message)
        Log a message at info level.
        Parameters:
        message - the message to log
      • info

        void info​(java.lang.String message,
                  java.lang.Object... args)
        Log a formatted message at info level.
        Parameters:
        message - the message to log
        args - the arguments for that message
      • warn

        void warn​(java.lang.Object message,
                  java.lang.Throwable exception)
        Log a message at warning level.
        Parameters:
        message - the message to log
        exception - the exception that caused the message to be generated
      • warn

        void warn​(java.lang.Object message)
        Log a message at warning level.
        Parameters:
        message - the message to log
      • warn

        void warn​(java.lang.String message,
                  java.lang.Object... args)
        Log a formatted message at debug level.
        Parameters:
        message - the message to log
        args - the arguments for that message
      • error

        void error​(java.lang.Object message,
                   java.lang.Throwable exception)
        Log a message at error level.
        Parameters:
        message - the message to log
        exception - the exception that caused the message to be generated
      • error

        void error​(java.lang.Object message)
        Log a message at error level.
        Parameters:
        message - the message to log
      • error

        void error​(java.lang.String message,
                   java.lang.Object... args)
        Log a formatted message at debug level.
        Parameters:
        message - the message to log
        args - the arguments for that message
      • fatal

        void fatal​(java.lang.Object message,
                   java.lang.Throwable exception)
        Log a message at fatal level.
        Parameters:
        message - the message to log
        exception - the exception that caused the message to be generated
      • fatal

        void fatal​(java.lang.Object message)
        Log a message at fatal level.
        Parameters:
        message - the message to log
      • fatal

        void fatal​(java.lang.String message,
                   java.lang.Object... args)
        Log a formatted message at debug level.
        Parameters:
        message - the message to log
        args - the arguments for that message