Invoke Java Web Start.
From the File menu, choose Preferences.
Select Manual option in the Preferences dialog.
Enter the following details:
HTTP Proxy. Enter the Name or the IP address of the proxy server.
HTTP Port. Enter the port number of the proxy server.
No Proxy_Hosts. Enter the name of any domain that you can connect directly, bypassing the proxy server. Use commas to separate multiple host names.
Click OK to save the proxy settings.