This is the fix I needed to do when installing Java. 
There are four, five or so items needed by 
  R CMD javareconf
Of those, `javah` was not found. 
There were several symlinks for the rest, but not javah. 
I made the symlink for that one, reran R CMD javareconf and the problem was fixed.

## THESE ARE THE TWO LINES OF CODE I RAN
ln -s /usr/java/latest/bin/javah /etc/alternatives/javah
ln -s /etc/alternatives/javah /usr/bin/javah
------

## THIS REPRESENTS THE OUTCOME I WANTED
##  (a symlink to a symlink)
/etc/alternatives/javah ~~>  /usr/java/latest/bin/javah
/usr/bin/javah ~~> /etc/alternatives/javah
------

## HERE IS PART OF THE   ls  OUTPUT.
lrwxrwxrwx    1 root root      21 Nov 12 13:22 jar -> /etc/alternatives/jar
lrwxrwxrwx    1 root root      22 Nov 12 13:22 java -> /etc/alternatives/java
lrwxrwxrwx    1 root root      23 Nov 12 13:22 javac -> /etc/alternatives/javac
lrwxrwxrwx    1 root root      24 Nov 12 13:22 javaws -> /etc/alternatives/javaws


root@[R Box]: alternatives# pwd
/etc/alternatives
root@[R Box]: alternatives# ls -alh | grep j
lrwxrwxrwx    1 root root   24 Nov 12 13:22 jar -> /usr/java/latest/bin/jar
lrwxrwxrwx    1 root root   29 Nov 12 13:22 java -> /usr/java/latest/jre/bin/java
lrwxrwxrwx    1 root root   26 Nov 12 13:22 javac -> /usr/java/latest/bin/javac
lrwxrwxrwx    1 root root   31 Nov 12 13:22 javaws -> /usr/java/latest/jre/bin/javaws
lrwxrwxrwx    1 root root   42 Nov 12 13:22 libjavaplugin.so -> /usr/java/jre1.7.0_45/lib/i386/libnpjp2.so
lrwxrwxrwx    1 root root   43 Nov 12 13:22 libjavaplugin.so.x86_64 -> /usr/java/jre1.7.0_45/lib/amd64/libnpjp2.so