Keywords: current

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### 1.8.2.1 A Complete Java Program

The following simple program

    class Motto {
      public static void main(String[] args) {
        System.out.println("Java rules!");
      }
    }

prints the `String` output

> Java rules!

and stops when the Java program with root-class Motto is executed. Before any Java program can be executed, it must be compiled into a form suitable for machine execution called a class file `Motto.class`. The name of the class file generated for a class C is simply C`.class`.

In DrJava, the Compile button applies the compiler to each open Java files and write out the resulting class files to the file system--assuming that the files did not contain any syntax errors. Each class file is stored in the same direcoty as the corresponding source (`.java`) class.

Finger Exercise: Using DrJava, define the `Motto` class given above and execute it as program.