Viewing Logs of the HelloWorld Application 
After the successful deployment, you can view the logs from your application in the Log Viewer tool.
Procedure
Start the SAP NetWeaver Administrator, entering the following data: http://<host>:<port_number>/nwa.
Choose
Problem Management 
Logs and Traces Log Viewer 
.Choose
Show View General SAP Logs (Java) .In the table below, find the logs from your application.
To see details, expand the relevant log record.
More Information
You can also view the application logs using the tools SAP Management Console and Command Console Log Viewer.
More information: Log Viewing with the SAP MC