Thanks Roedy! That site is very helpful, where was it when I first
started out Java programming, it could have helped/explained things
immensely.

I guess I should have explained my purpose a little more clearly in the
original post. What I am trying to achieve is a log file. It logs
events in a program, but I would like for it to be in a binary format
so it is not easily readable by opening the file in a text editor. The
writeUTF works, but I cannot for the life of me understand why the
ObjectOutputStream would not work. Can anyone explain that?

This does not work, i.e. If I run this program multiple times, the only
output I ever get is "1, 2, 3, 4". Why is that?

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.lang.ClassNotFoundException;

class ReadFile {

   ReadFile() {
   }

   public static void main(String[] args) {
    try {
       FileOutputStream fos = new FileOutputStream("josh.log", true);
       BufferedOutputStream bos = new BufferedOutputStream(fos);
       ObjectOutputStream oos = new ObjectOutputStream(bos);

       oos.writeObject("1");
       oos.writeObject("2");
       oos.writeObject("3");
       oos.writeObject("4");
       oos.close();

       FileInputStream fis = new FileInputStream("josh.log");
       BufferedInputStream bis = new BufferedInputStream(fis);
       ObjectInputStream ois = new ObjectInputStream(bis);

       while (true) {
        System.out.println((String)ois.readObject());
       }
    } catch (IOException exp) {
       System.out.println("Exception");
    } catch (ClassNotFoundException exp) {

    } finally {

    }
   }
}

This example works:

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.lang.ClassNotFoundException;

class ReadFile {

   ReadFile() {
   }

   public static void main(String[] args) {
    try {
       FileOutputStream fos = new FileOutputStream("josh.log", true);
       BufferedOutputStream bos = new BufferedOutputStream(fos);
       DataOutputStream dos = new DataOutputStream(bos);

       dos.writeUTF("1");
       dos.writeUTF("2");
       dos.writeUTF("3");
       dos.writeUTF("4");
       dos.close();

       FileInputStream fis = new FileInputStream("josh.log");
       BufferedInputStream bis = new BufferedInputStream(fis);
       DataInputStream dis = new DataInputStream(bis);

       while (true) {
        System.out.println(dis.readUTF());
       }
    } catch (IOException exp) {
       System.out.println("Exception");
    } finally {

    }
   }
}

Thanks a lot for all your responses.

Any reason why you wouldn't just use a BufferedWriter to write Strings
to a file?