Package org.apache.commons.configuration2.io

Class ConfigurationLogger

java.lang.Object
org.apache.commons.configuration2.io.ConfigurationLogger
public class ConfigurationLogger extends Object

A class providing basic logging capabilities.

When reading configuration files in complex scenarios having log output is useful for diagnostic purposes. Therefore, Commons Configuration produces some logging output. As concrete projects have different requirements on the amount and detail of logging, there is a way of configuring logging: All classes derived from AbstractConfiguration can be assigned a logger which is then used for all log statements generated.

Allowing a logger object to be passed to a configuration creates a direct dependency to a concrete logging framework in the configuration API. This would make it impossible to switch to an alternative logging framework without breaking backwards compatibility. To avoid this, the ConfigurationLogger class is introduced. It is a minimum abstraction over a logging framework offering only very basic logging capabilities. The methods defined in this class are used by configuration implementations to produce their logging statements. Client applications can create specialized instances and pass them to configuration objects without having to deal with a concrete logging framework. It is even possible to create a subclass that uses a completely different logging framework.

Since:
2.0

  • Constructor Details

    • ConfigurationLogger

      protected ConfigurationLogger()
      Creates a new, uninitialized instance of ConfigurationLogger. This constructor can be used by derived classes that implement their own specific logging mechanism. Such classes must override all methods because the default implementations do not work in this uninitialized state.

    • ConfigurationLogger

      public ConfigurationLogger(Class<?> logCls)
      Creates a new instance of ConfigurationLogger that uses a logger whose name is derived from the provided class.
      Parameters:
      logCls - the class whose name is to be used for logging (must not be null)
      Throws:
      IllegalArgumentException - if the logger class is null

    • ConfigurationLogger

      public ConfigurationLogger(String loggerName)
      Creates a new instance of ConfigurationLogger that uses the specified logger name.
      Parameters:
      loggerName - the logger name (must not be null)
      Throws:
      IllegalArgumentException - if the logger name is null

  • Method Details

    • newDummyLogger

      public static ConfigurationLogger newDummyLogger()
      Creates a new dummy logger which produces no output. If such a logger is passed to a configuration object, logging is effectively disabled.
      Returns:
      the new dummy logger

    • debug

      public void debug(String msg)
      Logs the specified message on debug level.
      Parameters:
      msg - the message to be logged

    • error

      public void error(String msg)
      Logs the specified message on error level.
      Parameters:
      msg - the message to be logged

    • error

      public void error(String msg, Throwable ex)
      Logs the specified exception on error level.
      Parameters:
      msg - the message to be logged
      ex - the exception to be logged

    • info

      public void info(String msg)
      Logs the specified message on info level.
      Parameters:
      msg - the message to be logged

    • isDebugEnabled

      public boolean isDebugEnabled()
      Returns a flag whether logging on debug level is enabled.
      Returns:
      true if debug logging is enabled, false otherwise

    • isInfoEnabled

      public boolean isInfoEnabled()
      Returns a flag whether logging on info level is enabled.
      Returns:
      true if debug logging is enabled, false otherwise

    • warn

      public void warn(String msg)
      Logs the specified message on warn level.
      Parameters:
      msg - the message to be logged

    • warn

      public void warn(String msg, Throwable ex)
      Logs the specified exception on warn level.
      Parameters:
      msg - the message to be logged
      ex - the exception to be logged