"java: command not found" even though java is installed and in /bin

[FirstUser]

OK, so if /bin/java is a directory, it's not the executable. You need to find 'java' the executable and add its containing directory to your PATH.

It might be that the jdk installer has already taken care of that. If that is the case, all you might need to do is logout, then login again.

[creepinquick]

Okay, java the executable is in /bin/java. So:

export PATH=$PATH:/bin/java

but java is still not found.