Can't tell when i have reached the end of the file

Question

Hi i'm trying to read a character at a time from a file but i can't tell the program when to stop when it has reached the end of the file
THis is the code
BufferedReader br = new BufferedReader(new FileReader("input_dat.txt"));
while ((c =(char) br.read()) != .....what should go here...)
     System.out.print((char)c);

Answer 1

i got it to work
hear is the code if anyone is interested .
int i= 0;
char c;
BufferedReader br = new BufferedReader(new FileReader("input_dat.txt"));
     while((i=br.read()) !=-1)
     c =(char) i;
     System.out.print((char)c);