BIRT Report Engine uses the java.util.logging classes, Logger and Level, to log information about the processing that the engine performs. When an application runs in the Eclipse workbench, by default, the messages appear in the console. When an application runs outside Eclipse, the default location of the log messages depends on the environment. The default logging threshold is Level.INFO. Typically, you change this level in your application to reduce the number of internal logging messages.

To set up the logging environment to write the engine’s log messages to a file, use the EngineConfig.setLogConfig( ) method. This method takes two arguments. The first argument is the directory in which to create the log file. The second argument is the lowest level at which to log information. Set the logging level to a high threshold so that the engine logs fewer messages. Typically, you want to see information at INFO level when you first develop a block of code. Use the ReportEngine.changeLogLevel( ) method to modify the amount of information that the engine logs. This method takes a single argument, which is a Level constant. When the code is stable, you no longer need to see all the engine’s INFO messages. At that point, delete or comment out the call to changeLogLevel( ). BIRT Report Engine creates a log file with a name of the format ReportEngine_YYYY_MM_DD_hh_mm_ss.log. To change this name, call EngineConfig.setLogFile( ). Use the EngineConfig methods, setLogRollingSize( ) and setLogMaxLogBackupIndex( ), to control the size and number of log files.