Module java.base
Package java.lang

Interface System.Logger

    • Method Detail

      • getName

        String getName​()
        Returns the name of this logger.
        Returns:
        the logger name.
      • isLoggable

        boolean isLoggable​(System.Logger.Level level)
        Checks if a message of the given level would be logged by this logger.
        Parameters:
        level - the log message level.
        Returns:
        true if the given log message level is currently being logged.
        Throws:
        NullPointerException - if level is null.
      • log

        default void log​(System.Logger.Level level,
                         String msg)
        Logs a message.
        Implementation Requirements:
        The default implementation for this method calls this.log(level, (ResourceBundle)null, msg, (Object[])null);
        Parameters:
        level - the log message level.
        msg - the string message (or a key in the message catalog, if this logger is a localized logger); can be null.
        Throws:
        NullPointerException - if level is null.
      • log

        default void log​(System.Logger.Level level,
                         Supplier<String> msgSupplier)
        Logs a lazily supplied message.

        If the logger is currently enabled for the given log message level then a message is logged that is the result produced by the given supplier function. Otherwise, the supplier is not operated on.

        Implementation Requirements:
        When logging is enabled for the given level, the default implementation for this method calls this.log(level, (ResourceBundle)null, msgSupplier.get(), (Object[])null);
        Parameters:
        level - the log message level.
        msgSupplier - a supplier function that produces a message.
        Throws:
        NullPointerException - if level is null, or msgSupplier is null.
      • log

        default void log​(System.Logger.Level level,
                         Object obj)
        Logs a message produced from the given object.

        If the logger is currently enabled for the given log message level then a message is logged that, by default, is the result produced from calling toString on the given object. Otherwise, the object is not operated on.

        Implementation Requirements:
        When logging is enabled for the given level, the default implementation for this method calls this.log(level, (ResourceBundle)null, obj.toString(), (Object[])null);
        Parameters:
        level - the log message level.
        obj - the object to log.
        Throws:
        NullPointerException - if level is null, or obj is null.
      • log

        default void log​(System.Logger.Level level,
                         String msg,
                         Throwable thrown)
        Logs a message associated with a given throwable.
        Implementation Requirements:
        The default implementation for this method calls this.log(level, (ResourceBundle)null, msg, thrown);
        Parameters:
        level - the log message level.
        msg - the string message (or a key in the message catalog, if this logger is a localized logger); can be null.
        thrown - a Throwable associated with the log message; can be null.
        Throws:
        NullPointerException - if level is null.
      • log

        default void log​(System.Logger.Level level,
                         Supplier<String> msgSupplier,
                         Throwable thrown)
        Logs a lazily supplied message associated with a given throwable.

        If the logger is currently enabled for the given log message level then a message is logged that is the result produced by the given supplier function. Otherwise, the supplier is not operated on.

        Implementation Requirements:
        When logging is enabled for the given level, the default implementation for this method calls this.log(level, (ResourceBundle)null, msgSupplier.get(), thrown);
        Parameters:
        level - one of the log message level identifiers.
        msgSupplier - a supplier function that produces a message.
        thrown - a Throwable associated with log message; can be null.
        Throws:
        NullPointerException - if level is null, or msgSupplier is null.
      • log

        default void log​(System.Logger.Level level,
                         String format,
                         Object... params)
        Logs a message with an optional list of parameters.
        Implementation Requirements:
        The default implementation for this method calls this.log(level, (ResourceBundle)null, format, params);
        Parameters:
        level - one of the log message level identifiers.
        format - the string message format in MessageFormat format, (or a key in the message catalog, if this logger is a localized logger); can be null.
        params - an optional list of parameters to the message (may be none).
        Throws:
        NullPointerException - if level is null.
      • log

        void log​(System.Logger.Level level,
                 ResourceBundle bundle,
                 String msg,
                 Throwable thrown)
        Logs a localized message associated with a given throwable.

        If the given resource bundle is non-null, the msg string is localized using the given resource bundle. Otherwise the msg string is not localized.

        Parameters:
        level - the log message level.
        bundle - a resource bundle to localize msg; can be null.
        msg - the string message (or a key in the message catalog, if bundle is not null); can be null.
        thrown - a Throwable associated with the log message; can be null.
        Throws:
        NullPointerException - if level is null.
      • log

        void log​(System.Logger.Level level,
                 ResourceBundle bundle,
                 String format,
                 Object... params)
        Logs a message with resource bundle and an optional list of parameters.

        If the given resource bundle is non-null, the format string is localized using the given resource bundle. Otherwise the format string is not localized.

        Parameters:
        level - the log message level.
        bundle - a resource bundle to localize format; can be null.
        format - the string message format in MessageFormat format, (or a key in the message catalog if bundle is not null); can be null.
        params - an optional list of parameters to the message (may be none).
        Throws:
        NullPointerException - if level is null.