Logger Guide

Loggers

Log.apex use logger objects to print logging information.

private static final Log logger = Log.getLogger(MyClass.class);

logger.debug('Debug message');

private static final Log logger = Log.getLogger(MyClass.class);

​

logger.debug('Debug message');

Logger Creation

We have two ways to create loggers.

• Create By Class We can pass in a class to create a logger.

private static final Log logger = Log.getLogger(MyClass.class);

private static final Log logger = Log.getLogger(MyClass.class);

• Create By Name We can pass in a name to create a logger.

private static final Log logger = Log.getLogger('MyClass');

private static final Log logger = Log.getLogger('MyClass');

Methods are below:

Log Levels

We support these logging levels in Log.apex.

Print Logs

We can print logs in the following ways:

• Simple message We output a simple message using the logger.

logger.debug('Debug message');

logger.debug('Debug message');

• Parameterized message We show a parameterized message, with parameters passed in.

logger.debug('Debug {0}', 'message');

logger.debug('Debug {0}', 'message');

Users should avoid concatenating strings in the logging method. Instead, use the parameterized messages, as the actual interpolation of the message is only triggered when the logging is enabled. So this will avoid unnecessary performance penalty.

• Controlled logging We can even check if the logging is enabled before we do the logging.

if(logger.isDebugEnabled()) {
    logger.debug('Debug {0}', getComplexResult());
}

if(logger.isDebugEnabled()) {

    logger.debug('Debug {0}', getComplexResult());

}

This will help avoid complicated computation for the parameter values if the logging is actually disabled.

Available methods are below: