When did it work? What happened since? Did you upgrade? Is the input file the same as in previous successful runs?
You might get more insight into the result of the readLine if you would change it to this code:
String line = "";
while (line != null) {
System.out.println(line);
try{
line = br.readLine();
}
catch (IOException e) {
System.err.println("Caught IOException: " + e.getMessage());
}
catch(Exception e){
//Handle the other error(s)
}
}
Hope it helps.