I would like to use zypper to install java, but when I type the instruction into terminal I get :libzypp is in use by another application. How do I find out which application and how do I stop it. As far as I can see, it is not being used by anything else.
To see which processes are using a specific library, use the ldd command.
The ldd command requires a location for the library file. Most of the library files can be found in the /usr/lib directory. There can also be more than one libzypp file, so let’s find which ones are in the /usr/lib directory: issue the command cd /usr/lib into the terminal window. After that, issue the command ls -l (those are Ls as in Letter, not 1s) and that will give you a list of all the files and directories in that folder. Near the buttom should be a file called libzypp.so.xxx-x.x (with the Xs representing numbers). If you find these, run the command…
ldd /usr/lib/libzypp.so.xxx-x.x
But, be sure to replace the Xs with the version of the file you found. If there is another libzypp file, be sure to run the ldd command for that as well.
I hope that helps. 
The answer is in the FAQ - openSUSE-Community :
“A ZYpp transaction is already in progress”
If you get this error at any time, make sure that all programs that might be using the package management system have been closed down. This includes Zypper, Smart, and most YaST processes. If you are sure that none of these are running, then one of them might be misbehaving. To kill the offending process, execute:
su -c “kill -9 $(lsof -t /usr/lib/libzypp*)”
> su -c “kill -9 $(lsof -t /usr/lib/libzypp*)”
This just brings up usage for kill. Logging off doesn’t stop the
processes either.