ePnta5nT

1private void readUserFile(String filename) {
2
3    try {
4
5        //Verify if file users exists
6        boolean exists = (new File(filename)).exists();
7
8        if (!exists) {
9            //If file users not exists create one, bases on distinct users that exist in ratings table 
10
11            ResultSet rsUsers = jdbcTemplate.getDataSource().getConnection().createStatement().executeQuery("SELECT DISTINCT UserID FROM ratings order by UserID;");
12
13            List<String> users = new ArrayList<String>();
14
15
16
17            while (rsUsers.next()) {
18
19                users.add(String.valueOf(rsUsers.getInt(1)));                  
20            }
21
22            rsUsers.close();
23
24            //Create and write to file
25            BufferedWriter f = null;
26            f = new BufferedWriter(new FileWriter(filename));
27
28            for (String user : users) {
29                f.write(user);
30                f.newLine();
31            }
32            f.close();
33
34        }
35
36        PreparedStatement prstInsert = con.prepareStatement("INSERT INTO users VALUES (?)");
37        BufferedReader in = new BufferedReader(new FileReader(filename));
38        int i = 0;
39        while (true) {
40            String s = in.readLine();
41            if (s == null) { // end of file 
42                log.info("Total imported users: " + i);
43                break;
44            }
45            i++;
46
47            int userid = Integer.parseInt(s);
48            prstInsert.setInt(1, userid);
49
50            if (i != 0 && Math.round((double) i / 100) == ((double) i / 100)) {
51                log.info("Imported users: " + i);
52            }
53            prstInsert.executeUpdate();
54        }
55    } catch (FileNotFoundException e) {
56        e.printStackTrace();
57    } catch (IOException e) {
58        e.printStackTrace();
59    } catch (SQLException e) {
60        e.printStackTrace();
61    }
62}