Page History

/**
 * LogActor the entity that is stored as in a ThreadLocal and used to perform logging.
 *
 * The actor is responsible for formatting its display name for the log entry.
 * 
 * The actor performs the requested logging.
 */
public interface LogActor
{
    /**
     * Logs the specified LogMessage about the LogSubject
     *
     * Currently logging has a global setting however this will later be revised and
     * as such the LogActor will need to take into consideration any new configuration 
     * as a means of enabling the logging of LogActors and LogSubjects.
     *
     * @param actor   The actor that is requesting the logging
     * @param message The message to log
     */
    public void message(LogSubject subject, LogMessage message);
}

/**
 * Each LogSubject that wishes to be logged will implement this to provide their
 * own display representation.
 * 
 * The display representation is retrieved through the toString() method.
 */
public interface LogSubject
{
    /**
     * Logs the message as provided by String.valueOf(message).
     *
     * @returns String the display representation of this LogSubject
     */
    public String toString();
}

/**
 * The RootMessageLogger is used by the LogActors to query if
 * logging is enabled for the requested message and to provide the actual
 * message that should be logged.
 */
public interface RootMessageLogger
{
    /**
     * Determine if the LogSubject and the LogActor should be
     * generating log messages.
     *
     * @param logSubject The subject of this log request
     * @param logActor   The actor requesting the logging
     * @return boolean true if the message should be logged.
     */
    boolean isMessageEnabled(LogActor actor, LogSubject subject);

    /**
     * Log the raw message to the configured logger.
     *
     * @param message   The message to log
     * @param throwable Optional Throwable that should provide stact trace
     */
    void rawMessage(String message, Throwable throwable);
}

/**
 * A RawMessage Logger takes the given String and any Throwable and writes the
 * data to its resource.
 */
public interface RawMessageLogger
{
    /**
     * Log the message and formatted stack trace for any Throwable.
     *
     * @param message   String to log.
     * @param throwable Throwable for which to provide stack trace.
     */
    public void rawMessage(String message, Throwable throwable);
}