Packages

Directory Structure when using Packages

• The directory structure must match the package name structure.
• When you run the class the full class name must be supplied i.e. "com.example.HelloWorld"
• You don't have to compile and run the javacode out of the current directory.

Commonly used javac options

• - d option sets a destination directory for writing the ".class" files
• - sourcepath option sets a source code search path.
• -cp or -classpath option sets the search path for finding external and previously compiled classes.
• -version option prints out compiler's version information.
• -target is used to compile code to an older version of java.
• -source recompile older java code to newer java platform to run on new platform.
• javac -source 1.4 oldsyntax.java
• javac -target 1.4 SomeClass.java
• -bootclass path - used to compile against an alternative set of run-time libraries
• javac -target 1.4 --bootclaspath path/to/java 1.4/rt.jar SomeClass.java