Handlers
Grace Software
JavaLog

$Revision: 1.1 $
$Date: 1999/10/11 00:05:13 $

Introduction

Handlers are classes that perform some final output action on log events. The Log class distributes its events to each Handler that is installed at runtime (via properties usually). One can think of Handlers as a kind of device driver adapter for the Log. So, at run time, one can configure the program to write all events to the standard out, errors to one file, traces to another file, and errors and warnings to JDBC database.

By default, JavaLog only logs to the standard out using the StandardOutHandler called out. If the user specifies any alternative handler at runtime, the StandardOutHandler out is not installed and, thus, log events are logged only to the Handlers explicitly configured by the run time user. For more information, see How To log to the standard out.

Handler Names

Each Handler must have a unique name so that multiple properties may be specified for each Handler. As written above, the default StandardOutHandler is named out. Therefore, to configure any property for this Handler, one would refer to the Handler by the prefix log.handler.out. and then append the desired property name to it. For example,
    $ java -Dlog.handler.out.stream=err MyClass
would write the log events to the System.err instead of System.out.

Other than out, Handler names are purely the user's design.