DBCP Connections pool connection stuck after no using

Question

We stuck with a strange issue in java with Oracle connections pool

If java program gets new data all the time no issue discovered. But if for a long period no requests to DB, and we try make a request it's stuck for 15 minutes. Only after 15 minutes processor gets new data.

Any ideas where to search timeouts or stuck connections or use some connection parameters?

Thanks,

Ilya

Using: DBCPConnectionPool

Java version: 1.8.0_112

Driver: ojdbc8.jar

Oracle server version: 11.2.0.4.0 (11g)