BufferedReader won't read.

Question

Got a simple program that checks if the file "adressbok.txt" contains any text.
If it does, the program reads that text and writes it again and also writes a new String indata.
The problem is that my program gets stuck in the while-loop. I suppose the break-code kicks in but I don't understand why? I've specified that the code should break only if the nextline equals null.
My Question: How do I modify the code below so that the program DOESN'T go to break automatically. What am I missing here?
The specific code is:
BufferedReader    inFil = new BufferedReader (new FileReader ("Adressbok.txt"));
PrintWriter    utFil = new PrintWriter (new BufferedWriter (new FileWriter ("Adressbok.txt")));
while (true)
     String    rad = inFil.readLine ();
     if (rad == null)
          break;
     utFil.println (rad);
String indata = "test";
utFil.write (indata);

Answer 1

I wan't the program to add a new contact to the file adressbok.txt. The program asks for a name and an adress and then writes it to the txt-file.
However, I want it to add that person at the bottom of the file. (I don't care about alphabetical order just yet). Also, I want to do this without using RandomAccessFile.
If I use FileWriter it simply erases the previous content of the txt-file. Therefor I created the while-loop so that the program could:
1. Read the previous content of the txt
2. Write it again
3. break when there is no more to read from
4. "jump out" of the loop and continue writing the new information.