/bin/bash: jar: command not found
Solution:
cd /usr/bin
You must first enter /usr/bin, the same below
sudo ln -s -f /usr/lib/jvm/jdk1.6.0_30/bin/jar
My jdk is installed in the /usr/lib/jvm/jdk1.6.0_30/ directory
If it prompts javah: commond not found, then draw the scoop according to the gourd and enter the command
cd /usr/bin
ln -s -f /usr/lib/jvm/jdk1.6.0_30/bin/javah