If you are trying to install SMSDOM 8.1.2 with Java 8 you will see an error saying Java 4 and above is required. If you have a fully working SMSDOM 8.1.2 with Java 7 and then uninstall Java 7 to install Java 8 when you run Liveupdate from the GUI you will receive the error "Could not locate installation directory".
Prior to SMS DOM 8.1.2, Java 7 was not certified. For versions prior to 8.1.2, please review TECH188687.
How to use Java 7 with SMSDOM 8.x
Release SMSDOM 8.1.3 is now certified for Java 8.
How to use Java 8 with SMSDOM 8.1.3
Oracle has announced End of Public Updates scheduled for April 2015 for Java 7.
Oracle Java SE Support Roadmap
As stated in Oracle Java SE Support Roadmap, Long Term Support will be available. Java SE enhancements and critical bug fixes should be available under the Oracle Technology Network. Please consult Oracle's Technical Support, if you have further questions about Java SE supportability
Oracle Java SE Support
Symantec Technical Support provides the following as a workaround. It is the recommendation to leverage Symantec Mail Security for Domino 8.1.3 for Java 8 deployments.
If you are installing SMSDOM 8.1.2 with LiveUpdate you will need to install Java 7 first to satisfy the installer check.
Once you have a working environment you can now install Java 8 and then install the JCE for Java 8. You can download the JCE as provided below.
Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 8 Download
Open the notes.ini file and change the path for SAVJava= line to point to the Java 8 bin folder. If this line does not exist, you can just add it to your notes.ini. Here is an example: SAVJava=C:\Program Files\Java\jre8\bin\
Now when you run LiveUpdate it will use this path and run using Java 8.
NOTE: If you have SMSDOM installed without LiveUpdate you will then need to follow the steps at one of the following technotes depending on your environment that matches yours and then just substitute installing Java 6 with Java 8 in the steps.
Windows 64bit/Domino 64bit/SMSDOM 64bit - http://www.symantec.com/docs/tech178338
Windows 64bit/Domino 32bit/SMSDOM 32bit - http://www.symantec.com/docs/tech178336
Windows 32bit/Domino 32bit/SMSDOM 32bit - http://www.symantec.com/docs/tech178332