API changes (WIP)

/**
 * Interface used by CDAP applications to log the data useful for debugging during runtime.
 */
public interface DebugLoggerFactory {
  /**
   * Returns {@code true} if application is running in debug mode otherwise false is returned.
   */
  boolean isEnabled();

  /**
   * Get the {@link Logger} used to log the debug data.
   * @param loggerName the name of the logger with which the log data to be associated
   * @return the instance of the Logger
   */
  Logger getLogger(String loggerName);
}
 
/**
 * Interface used by the CDAP applications to log the debug data.
 */
public interface Logger {
  /**
   * Logs the data at INFO level. Multiple values can be logged against the same property.
   * @param propertyName the the name of the property
   * @param propertyValue the value associated with the property
   */
  void info(String propertyName, Object propertyValue);
 
  /**
   * Logs the data at DEBUG level. Multiple values can be logged against the same property.
   * @param propertyName the the name of the property
   * @param propertyValue the value associated with the property
   */
  void debug(String propertyName, Object propertyValue);

  /**
   * Logs the data at ERROR level. Multiple values can be logged against the same property.
   * @param propertyName the the name of the property
   * @param propertyValue the value associated with the property
   */
  void error(String propertyName, Object propertyValue);
 
  /**
   * Return the name of the logger instance.
   */ 
  String getName(); 
}