Why are there a series of technical challenges behind “OMG buy it”>>> 
#sudo tar zxvf ./jdk-7ull-linux-i586.tar.gz -C /usr/lib/jvm
gzip: stdin: not in gzip format
tar: Child returned status 1
tar: Error is not recoverable: exiting now
The solution to the problem is as follows: change Z parameter to j parameter to solve the problem
BZ format with J
GZ format with Z
Other command parameters
C is to create
x is to decompress
V is to detail
F is to specify the file
