import java.io.*;
class FileInputStreamDemo {
  public static void main(String args[]) throws Exception {
    int size;
    InputStream f = new FileInputStream("FileInputStreamDemo.java");
    System.out.println("Total Available Bytes: " +
                       (size = f.available()));
    int n = size/40;
    System.out.println("First " + n +
                     " bytes of the file one read() at a time");
    for (int i=0; i < n; i++) 
      { System.out.print((char) f.read()); }
    System.out.println("\nStill Available: " + f.available());
    System.out.println("Reading the next " + n +
                       " with one read(b[])");
    byte b[] = new byte[n];
    if (f.read(b) != n) 
      { System.err.println("couldnt read " + n + " bytes.");; }
    System.out.println(new String(b, 0, n));
    System.out.println("\nStill Available: " 
                       + (size = f.available()));
    System.out.println("Skipping half of " 
                       + "remaining bytes with skip()");
    f.skip(size/2);
    System.out.println("Still Available: " + f.available());
    System.out.println("Reading " + n/2 + " into the end of array");
    if (f.read(b,n/2,n/2) != n/2) {
      System.err.println("couldnt read " + n/2 + " bytes.");
    }
    System.out.println(new String(b,0,b.length));
    System.out.println("\nStill Available: " + f.available());
    f.close();
  }
}