Change the log level of java.util.logging loggers at runtime.
LogLevelChanger is a small CLI program for adjusting the java.util.logging log levels of a process at runtime.
Other logging libraries already provide a way to modify the log levels at runtime by rereading the logging configuration or maybe by other means, but java.util.logging does not provide such a functionality out of the box.[1]
LogLevelChanger can be used with Java 6 to 8, but is not compatible with Java 9 or higher.
As LogLevelChanger uses the tools.jar provided by the JDK an installation of the JDK must be available.
LogLevelChanger is provided as a zipfile or tarball at the Download page. These contain the jar file and a shell script to run it. The shell script is only provided for Unix-like systems at the moment. Expand of these archives to a directory of your choice.
Run LogLevelChanger via the provided shell script. Without any parameters it provides a usage note and exits.
SYNOPSIS
LogLevelChanger PID [LOGGER [LOGLEVEL]]
DESCRIPTION
Prints or changes the LogLevels of Loggers of a Java process.
Without any arguments (apart from the PID), it prints all the
loggers and their configured LogLevels.
If only the LOGGER is given, it prints out the LogLevel of that
Logger.
If both, the LOGGER and the LOGLEVEL are given, it sets the
LogLevel of the given Logger.
PARAMETERS
PID
The PID of the process for which to print or change the LogLevels.
LOGGER
The name of the Logger to print or the change the LogLevel of.
LOGLEVEL
The log level to set for the given Logger.LogLevelChanger is licensed under the terms of the GPL 2 with Classpath Exception.