public static void main(String[] args) {

        String sqlQuery = "SELECT id,PrimaryIP from IPTable where PrimaryIP != '' limit 100000;";
        Connection connection = null;
        Statement statement = null;
        File oFile = new File("output.txt");
        System.out.println(new Date());
        try{
            List<String> fileData = FileUtils.readLines(new File("input.txt"));
            System.out.println("File Data Size : "+fileData.size());

            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection("jdbc:mysql://localhost/db?user=root&password=pwd");

            statement = connection.createStatement();
            ResultSet resultSet = statement.executeQuery(sqlQuery);

            System.out.println("Started with MySQL Querying");

            Map<String, Integer> primaryIPIDMap = new HashMap<String, Integer>();

            while (resultSet.next()) {
                primaryIPIDMap.clear();
                int recordID = resultSet.getInt(1);

                if (resultSet.getString(2).contains("#")) {
                    String primaryIP[] = resultSet.getString(2).split("#");

                    for (int i = 0; i < primaryIP.length; i++) {
                        if (primaryIP[i].contains("/")) {
                            String allIP[] = getAllIP(primaryIP[i]);
                            for (int allIPi = 0; allIPi < allIP.length; allIPi++) {
                                primaryIPIDMap.put(allIP[allIPi].intern(), recordID);
                            }
                        } else {
                            primaryIPIDMap.put(primaryIP[i].intern(), recordID);
                        }
                    }
                } else {
                    primaryIPIDMap.put(resultSet.getString(2).intern(), recordID);
                }

                Iterator entries = fileData.iterator();
                while (entries.hasNext()) {
                    String t = (String) entries.next();
                    if (primaryIPIDMap.containsKey(t)) {
                        FileUtils.writeStringToFile(oFile, recordID + "," + t);
                    }
                }
                primaryIPIDMap.clear();
            }

            resultSet.close();
            statement.close();
            connection.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (statement != null)
                    statement.close();
            } catch (Exception se2) {
            }
            try {
                if (connection != null)
                    connection.close();
            } catch (Exception se) {
                se.printStackTrace();
            }
        }

        System.out.println("Finished");
        System.out.println("End Time : "+new Date());
    }

    private static String[] getAllIP(String ip) {
        return new SubnetUtils(ip).getInfo().getAllAddresses();
    }

try ( Connection connection = /*...*/ ;
      Statement statement = /*...*/ ) {
    try ( BufferedReader in = Files.newBufferedReader(input, charset);
          BufferedWriter out = Files.newBufferedWriter(output, charset) ) {
        for ( String line = in.readLine(); line != null; line = in.readLine() ) {
            // 1. parse line
            // 2. query database
            // 3. write out result
        }
    }
}

zcat input.gz | java pkg.MyAwesomeFilter | gzip > output.gz

10.0.0.0     -> 010 000 000 000
192.168.1.11 -> 192 168 001 011

List<String> fileData = FileUtils.readLines(new File("input.txt"));