Logging Configuration

JLine does not depend on any existing logging framework, instead it uses the simple logging facility in jline.internal.Log.

The default behavior is to send log messages to System.err (by default only WARN and ERROR messages are enabled). The stream can be changed programmatically with:

jline.internal.Log.setOutput(final PrintStream out)

Since 2.13, the log can be delegated to the jline logger of the java.util.logging framework by using the following property:

jline.log.jul=true

To enable DEBUG messages configure the property:

jline.internal.Log.debug=true

To enable TRACE messages configure the property:

jline.internal.Log.trace=true

Since 2.7 TRACE implies DEBUG.