File Input Output Java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class FileIOApp {
  public static void main(String args[]) throws IOException {
    FileOutputStream outStream = new FileOutputStream("test.txt");
    String s = "This is a test.";
    for (int i = 0; i < s.length(); ++i)
      outStream.write(s.charAt(i));
    outStream.close();
    FileInputStream inStream = new FileInputStream("test.txt");
    int inBytes = inStream.available();
    System.out.println("inStream has " + inBytes + " available bytes");
    byte inBuf[] = new byte[inBytes];
    int bytesRead = inStream.read(inBuf, 0, inBytes);
    System.out.println(bytesRead + " bytes were read");
    System.out.println("They are: " + new String(inBuf));
    inStream.close();
    File f = new File("test.txt");
    f.delete();
  }
}