HMC Shortcuts
Since java is a prefix of javac, this tends to confound using command completion (e.g. !j in the Cshell).
In your .cshrc should be the following command definitions:

alias jc 'javac \!$.java'            #compile java 
alias je 'java'                        #execute
alias jx 'javac \!$.java ; java \!$'   #compile and execute

Example usage:

jc Hello # same as javac Hello.java
je Hello # same as java Hello
jx Hello # same as javac Hello.java; java Hello

Then use !jc, !je, or !jx to re-do previous commands of same type.