The error means that there is no executable file "java" that the shell
thinks it can call.

Shells look at all the directories in the environment variable PATH: If an
executable file "java" is there, it is called.

If an alias is defined properly, it is called.

Otherwise, replace "java" by the full pathname (below /usr/java5, perhaps)
or use the approach I suggested earlier, define a shell variable (JAVA)
with the full path and use its expansion ($JAVA) instead.

-W