Looks like java is in your path, but you'll still need the JAVA_HOME environment variable set. Here's how to set it:
$ export JAVA_HOME=/path/to/java
I think you can also put the export command into a shell script named setJavaHome.sh and put that shell script in the same directory as the start-clearspace.sh. Then when you run the start-clearspace.sh script it will auto run the setJavaHome so you don't have to do an export each time. I haven't actually tried this on linux but it works on windows using the batch files.
Thanks! All works.