Why use IOexception instead of Exception when catching?

I can't seem to phrase this correctly for the search engine to pick up any meaningful results.

try{
    BufferedReader reader = new BufferedReader( new FileReader("foo.bar") );
}
catch(Exception e){
    println( e.getMessage() );
}

So FileReader only throws the FileNotFoundException, which as I understand it is an IOException, which is an Exception. Can someone explain why I would catch FileNotFoundException or IOException instead of just specifying the generic "Exception" and not having to import an exception (i.e. import java.io.FileNotFoundException;)? Is it strictly for readability?

I've caught the exception using all three names and I can't find a difference.

EDIT:--------------------

private BufferedReader askUserForFile(String prompt){
        BufferedReader rd = null;
        while(rd == null){
            try{
                String filename = readLine(prompt);
                rd = new BufferedReader( new FileReader(filename) );
            }
            catch(Exception e){
                println(e.getMessage());
            }
        }
        return rd;
    }