There is an article at InfoQ that discusses Oracle’s support strategy . It
contains a chart that shows the support lifetime for all Oracle releases. 
It references a blog post from Azul discussing Oracle’s support strategy. 
These charts are confirmed by Oracle’s roadmap. . The end of public updates
for Java 7 was in April 2015 and the end of premier support is July 2019. 
First, based on this and the decline in the interest in Java 7 and that we are
now about 3 years past the last public updates I am fine with making Java 8 our
minimum version along with the release of Log4j 3.0. FWIW, while SLF4J still
supports Java 5, as of today Logback 1.3.0 now requires a minimum of Java 8.
After that things start to get strange. I think we will have to take advantage
of the multi-release jar support more and more in the future because I don’t
see how we could ever make Java 9 or 10 the minimum supported version since
Oracle will effectively drop support for them 6 months after they are
introduced. I would think we would have to wait until Java 8 usage declines to
the levels Java 7 currently is before upgrading and at that time we would have
to skip all the way to Java 11.
Whatever we decide to do I would prefer if we could publish our JVM support
strategy on the web site.