Código de Java - Lee un archivo

import java.io.*;

class ReadBinaryFile

{

    public static void main(String[] args)

    {

        // The name of the file to open.

        String fileName = "file.txt";

        FileInputStream inputStream = null;

        try

        {

            // Use this for reading the data.

            byte[] buffer = new byte[1000];

            inputStream = new FileInputStream(fileName);

            // read fills buffer with data and returns

            // the number of bytes read (which of course

            // may be less than the buffer size, but

            // it will never be more).

            int total = 0;

            int nRead = 0;

            while ((nRead = inputStream.read(buffer)) != -1)

            {

                // Convert to String so we can display it.

                // Of course you wouldn't want to do this with

                // a 'real' binary file.

                System.out.println(new String(buffer));

                total += nRead;

            }

            System.out.println("Read " + total + " bytes");

        }

        catch (FileNotFoundException ex)

        {

            System.out.println("Unable to open file '" + fileName + "'");

        }

        catch (IOException ex)

        {

            System.out.println("Error reading file '" + fileName + "'");

            // Or we could just do this:

            // ex.printStackTrace();

        }

        finally

        {

            // Always close files.

            try

            {

                if (inputStream != null)

                {

                    inputStream.close();

                }

            }

            catch (IOException e)

            {

            }

        }

    }

}