When Java on Solaris was made LP64-only, the jexec executable needed to directly execute JAR files stopped being built and is no longer delivered. That means JAR files can no longer be directly executed on Solaris.

In addition, when built as LP64 the location of jexec in the JDK install tree changes from a 32 to a 64 bit subdirectory of the JDK install tree. The current locations where Solaris looks for jexec are:

/usr/java/jre/lib/sparc/jexec
/usr/java/jre/lib/i386/jexec

JDK-8066474 also proposes to remove the architecture-specific subdirectories from the JDK, in which case the new locations should probably be:

/usr/java/jre/lib/jexec
/usr/java/jre/lib/jexec