Your Talend Studio includes the Apache logging utility log4j to provide logging at runtime. You can enable or disable log4j loggers in components and customize the log4j configuration.
To do so:
On the toolbar of the Studio main window, click or click File > Edit Project Properties from the menu bar to open the [Project Settings] dialog box.
In the tree view of the dialog box, click the Log4j node to open the Log4j view.
Select the Activate log4j in components check box to activate the log4j feature.
You can change the log4j configuration by modifying the XML instructions in the Log4j template area. For more information on the log4j parameters, see http://wiki.apache.org/logging-log4j/Log4jXmlFormat.
For more information on how to use the log4j feature, see How to customize log4j output level at runtime.