Apache

Web Console Logging

The Web Console does not provide its own mechanism for logging. Rather the Servlet Container logging mechanism is used by calling the GenericServlet.log methods for logging. It is expected by the OSGi Http Service implementation implements these log methods writing to the OSGi Log Service.

The drawback of using servlet container logging is that we have no control over the logging levels used and applied to log messages. To at least allow some level of log message filtering the Web Console can be configured with a logging level using the loglevel property of the Apache Felix OSGi Management Console (org.apache.felix.webconsole.internal.servlet.OsgiManager).

The AbstractWebConsolePlugin class provides two addition log methods taking a level parameter which allow plugins to filter certain log messages:

log(int level, String message) Calls GenericaServlet.log(String) if the configured log level is less than or equal to the level parameter.
log(int level, String message, Throwable t) Calls GenericaServlet.log(String, Throwable) if the configured log level is less than or equal to the level parameter.

Note 1: The level parameter is just used for filtering calls to the GenericeServlet.log methods and cannot define the actual log level used by the servlet container.

Note 2: Direct calls to one of the GenericServlet.log or ServletContext.log methods are not intercepted and are not filtered by the log level configured for the Web Console.

The level parameter and the loglevel configuration property can be set to any of the constant values defined by the OSGi LogService class:

1 LOG_ERROR This log entry indicates the bundle or service may not be functional.
2 LOG_WARNING This log entry indicates a bundle or service is still functioning but may experience problems in the future because of the warning condition.
3 LOG_INFO This log entry may be the result of any change in the bundle or service and does not indicate a problem.
4 LOG_DEBUG This log entry is used for problem determination and may be irrelevant to anyone but the bundle developer.
Last modified by fmeschbe on 2010-03-15 09:19:52.0
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