The Java TM Tutorial

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Trail: Learning the Java Language
Lesson: The Nuts and Bolts of the Java Language

## Running the countChars Method

> The following `main` method for the `Count` class opens a `Reader` on a file named on the command line and then calls `countChars` with that `Reader`. You can use this application to run `countChars`.

> >     import java.io.*;
> >     public class Count {
> >         // ... countChars method omitted ...
> >         public static void main(String[] args) throws Exception
> >         {
> >             if (args.length >= 1)
> >                 countChars(new FileReader(args[0]));
> >             else
> >                 System.err.println("Usage: Count filename");
> >         }
> >     }

> The output of this program depends on what's in the file named on the command line. These platform-specific instructions show you how to run the application on a file named `testing` that contains the following ASCII text and displays the results:

> >     Ich bin ein Berliner.
> >     I am a jelly doughnut.

> Now that you've seen the `countChars` method in action, the remainder of this lesson looks at the various components that make up the method and how they fit into the Java language.

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