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Notes for [Java] / [javac]  users.

(''I use [Java] as a better [C++] and don't use any of the awt/swing stuff, so I can't help there, sorry''---StuartYeates)

!!!Makefile rules

make(1) and [Java] don't play very well together, because unless you're careful you end up starting a new VirtualMachine for every file you want to compile (see the 'classes' target below for a complete hack). Remember that tabs and spaces get confused when cutting and pasting (see MakeFile).

 JAVAC=javac
 JAVACOPTIONS= -g:none -O

 #make a .class file from a .java file
 %.class: %.java
         $(JAVAC) $(JAVACOPTIONS) $<

 # JAVACC stuff

 #name/location of javacc executable
 JAVACC=/home/say1/bin/javacc

 #javacc options
 JAVACCOPTIONS=-SANITY_CHECK=true -FORCE_LA_CHECK=true -DEBUG_PARSER=true -DEBUG_TOKEN_MANAGER=true

 # build a java file from a JavaCC file
 %.java: %.jj
         $(JAVACC) $(JAVACCOPTIONS) $<

 # a target that builds all the .java files in sight
 classes:
         $(JAVAC) $(JAVACOPTIONS) *.java */*.java */*/*.java

!!! Tool support

# JavaDoc is your friend.
# [Ant] is your friend.
# JavaDeps is your friend.
# [Eclipse] [IDE] is your friend (superseeds JavaDeps and integrates [Ant] and JavaDoc)

!!!Errors

Sometimes [javac]/[Java] complains that it can't find files which are plainly there or complains that they're in the wrong place. This is almost always a classpath or a package interaction problem. If the file is not in a package and is in the current directory:
#Check that the current directory is in the classpath
#Check whether you need to specific !ClassName or !ClassName.java
#Check spelling. Spelling matters.

If the file is in a package:
#Check the above points
#Check that the the file is in "/some/path/to/a/dircetory/some/package/heirarchy/!ClassName.java" and is called "!ClassName" and in "/some/package/heirarchy/" package
#Check that "/some/path/to/a/dircetory/" is in the the classpath
#Check that the current directory is not in the classpath
#Check the package name again

!The public type <name of class> must be defined in its own file
Check to make sure that the filename of the .java file has the same name as the class inside the file.

!!!How do I run a jar file?

A JAR file (or Java Archive) is a ZIP file used to distribute a set of Java classes. It is used to store compiled Java classes and associated metadata that can constitute a program.

To run a [Java] application that is inside a .jar file Simply type:

*java -jar <jar_file>

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