java io

read file

StringBuffer sb = new StringBuffer();
File f = new File(file);
if (f.exists()) {
    System.out.println("file not exist");
    try {
        BufferedReader br = new BufferedReader(new InputStreamReader(
            new FileInputStream(f)));
        while ((s = br.readLine()) != null) {
            sb.append(s);
        }
    } catch (Exception e) {
     e.printStackTrace();
    }
}