Using JDBC with Firewalls

from Oracle® Database JDBC Developer's Guide and Reference

http://docs.oracle.com/cd/B19306_01/java.102/b14355/apxtblsh.htm#CHDBBDDA

Firewall timeout for idle-connections may sever a connection. This can cause JDBC applications to hang while waiting for a connection. You can perform one or more of the following actions to avoid connections from being severed due to firewall timeout:

• If you are using connection caching or connection pooling, then always set the inactivity timeout value on the connection cache to be shorter than the firewall idle timeout value.
• Pass oracle.net.READ_TIMEOUT as connection property to enable read timeout on socket. The timeout value is in milliseconds.
• For both JDBC OCI and JDBC Thin drivers, use net descriptor to connect to the database and specify the ENABLE=BROKEN parameter in the DESCRIPTIONclause in the connect descriptor. Also, set a lower value for tcp_keepalive_interval.
• Enable Oracle Net DCD by setting SQLNET.EXPIRE_TIME=1 in the sqlnet.ora file on the server-side.