Where do i find the log file of Content Services Application?

All the content services exceptions are available in the application.log in

$ORACLE_HOME/j2ee/OC4J_Content/application-deployments/content/OC4J_Content_default_island_1/application.log

Oracle Workspaces exceptions are captured in the log file whose location is as mentioned below.

$ORACLE_HOME/j2ee/OC4J_OCSClient/application-deployments/workspaces/OC4J_OCSClient_default_island_1/application.log