java read file text

1try(BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
2    StringBuilder sb = new StringBuilder();
3    String line = br.readLine();
4
5    while (line != null) {
6        sb.append(line);
7        sb.append(System.lineSeparator());
8        line = br.readLine();
9    }
10    String everything = sb.toString();
11}