Java Reference
In-Depth Information
ample, issue the following command to compile the
HelloWorld
class from Recipe
1-2.
Windows:
javac
org\java8recipes\chapter01\recipe1_02\HelloWorld.java
OS X:
javac org/java8recipes/chapter01/recipe1_02/
HelloWorld.java
You should now have a
.class
file in the same directory as your
.java
file. For
example:
dir org\java8recipes\chapter01\recipe1_02 /B
HelloMessage.class
HelloWorld.class
HelloWorld.java
Compilation produces two files. One is for
HelloMessage
, and the other is for
the class named
HelloWorld
implementing the
main()
method.
Execute the
main()
method by issuing the
java
command to invoke the Java
Virtual Machine (JVM). Pass the fully-qualified class name as a parameter to the com-
mand. Qualify the class name by prepending the package name, but this time use the
same dot-notation as used in your source file. For example:
java org.java8recipes.chapter1.recipe1_02.HelloWorld
Do not specify
.class
at the end of the command. You are referencing
Hel-
loWorld
now as a class name, and not as a file name. You should see the same output
as from Recipe 1-2.
Tip
One compiles source code. Source code is kept in files, so your operating-sys-
tem's file and directory-path notation is appropriate. One executes a class. A class is an
