Highlights or refreshers for people coming back to Java language

• Java is case-sensitive, HelloWorldApplication is different from helloworldapplication. And, common Java style uses jagged upper cases for class names such as HelloWorldApplication and not Helloworldapplication. Jagged convention is everything in Java culture and note that the variable names usually starts with a lower case word such as numberOfArgs.
• javac is the compiler for *.java code, java is to invoke JVM (Java virtual machine) to run your *.class file. The *.class files are created as a result of compilation. Remember that java file name *has* to match the java class name defined inside that file. As a rule, call the file that defines HelloWorldApplication class HelloWorldApplication.java.
• CLASSPATH is a common source of problems to run java code. Make sure that all required class files are in the CLASSPATH and in the right order.
• Java graphics user interface uses Java Foundation Class (JFC) and its graphical building component is usually referred to as the swing API.
• The static modifier tells of a class member or a class variable which is shared by all instances. We can view that the class is a template and the instance is an act of instantiation of the template.

Questions and Answers (competency test):

What is I18n and what is L10n?

What are typical ways translatable strings externalized?
Specifically what class is used by the Java programs and what
backing files are used and get translated to target languages?

What is 'char' type in the Java language?  How is it represented internally by
the Java virtual machine?  How do you deal with non-ASCII text outside
of Java, that is, what java.io class do you use to do read and write.

Can you use String.equals and String.compareTo methods to perform comparisons?


References:

Name some (at least 6) culturally dependent data in Java programs.


  Sun's Java I18n tutorial
  Sun's Java tutorial