Example Program

Recall that a text file is just like any file, except that its bytes must represent characters and a few control characters. Java programs can use other types of file as input, but this chapter will only discuss text files as input.

Here is a program that can be used with input redirection. Notice that it is written to do input from the keyboard:

class Echo
{
  public static void main ( String[] args ) throws IOException
  {
    String line;
    BufferedReader stdin = new BufferedReader( 
        new InputStreamReader( System.in ) );

    System.out.println("Enter your input:");
    line = stdin.readLine();

    System.out.println( "You typed: " + line );
   }
}

Here is how the program ordinarily works:

C:\users\default\JavaLessons>java Echo

Enter your input:
This came from the keyboard
You typed: This came from the keyboard

D:\users\default\JavaLessons>