Having installed CA SSO 12.52 SP1 on Windows 2008 SP2 32 bits. JVM used: 1.6.32 32 bits.
Planning to upgrade to CA SSO 12.8 on Windows 2012 64 bits. JVM used: 1.8.x 64 bits.
In the past, several Active Responses have been developed. They have been working fine for 5 years on JDK 1.6 and about CA SSO 12.0 and CA SSO 12.52 SP1. JDK 1.6 ( major 50 ) was in use.
Is a recompilation of the actual Custom Active Responses needed, to run under CA SSO 12.8 Policy Server?
Recompilation of the custom code with the new JVM is required, but also use the SDK 12.8 to insure that the functions that the custom code will use are at the exact level of the Policy Server one and they are up to date (1).
Depending on the code in use, test it as is with the new Policy Server. As java code is bit code and can be moved from version, there are chances that the former .jar files will still work fine with the new JDK and Policy Server.
If from those tests report execution problems, then recompile with the new JDK and SDK as per the ones that Policy Server runs.