StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
text
Body
copied!<p>You need to step away from letting the regex control you. If you define your structure in another way (I use an <code>enum</code> below) from which you can derive your regex and a formatter then not only will the code become much more extensible but you will also be able to make a marshaller and an unmarshaller from it too.</p> <p>Something like this may be a good start:</p> <pre><code>public class BankRecords { static enum AccountField { BANK_ID("\\d", 3) { @Override void fill ( Account a, String s ) { a.bankId = s; } }, ACCOUNT_ID("\\d", 12) { @Override void fill ( Account a, String s ) { a.accountID = s; } }, COMPANY_NAME(".", 20) { @Override void fill ( Account a, String s ) { a.companyName = s; } }, MONTH("\\d", 2) { @Override void fill ( Account a, String s ) { a.month = s; } }, DAY("\\d", 2) { @Override void fill ( Account a, String s ) { a.day = s; } }, YEAR("\\d", 2) { @Override void fill ( Account a, String s ) { a.year = s; } }, SEQUENCE("\\d", 12) { @Override void fill ( Account a, String s ) { a.seqNumber = s; } }, TYPE_CODE("\\d", 2) { @Override void fill ( Account a, String s ) { a.typeCode = s; } }; // The type string in the regex. final String type; // How many characters. final int count; AccountField(String type, int count) { this.type = type; this.count = count; } // Each field can fill its part in the Account. abstract void fill ( Account a, String s ); // My pattern. static Pattern pattern = Pattern.compile(asRegex()); public static Account parse ( String record ) { Account account = new Account (); // Fire off the matcher with the regex and put each field in the Account object. Matcher matcher = pattern.matcher(record); for ( AccountField f : AccountField.values() ) { f.fill(account, matcher.group(f.ordinal() + 1)); } return account; } public static String format ( Account account ) { StringBuilder s = new StringBuilder (); // Roll each field of the account into the string using the correct length from the enum. return s.toString(); } private static String regex = null; static String asRegex() { // Only do this once. if (regex == null) { // Grow my regex from the field definitions. StringBuilder r = new StringBuilder("^"); for (AccountField f : AccountField.values()) { r.append("(").append(f.type); // Special case count = 1 or 2. switch (f.count) { case 1: break; case 2: // Just one more. r.append(f.type); break; default: // More than that shoudl use the {} notation. r.append("{").append(f.count).append("}"); break; } r.append(")"); } // End of record. r.append("$"); regex = r.toString(); } return regex; } } public static class Account { String bankId; String accountID; String companyName; String month; String day; String year; String seqNumber; String typeCode; } } </code></pre> <p>Note how each <code>enum</code> encapsulates the essence of each field. The type, the number of characters and where it goes in the <code>Account</code> object.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload