Will Java JRE close connections when application crashes?

Will the Java JRE close database connections if applications fail or exit without closing active connections? If it is not the responsibility of the database to disconnect these connections?

I understand that if Java crashes, then the database will have to disconnect all open connections, since nothing else needs to be done.

EDIT Extra thought. If the WAR deployed to Tomcat fails, will the Tomcat server clear open connections?