CSVTransactionExtracter.java

// CSVTransactionExtracter

package org.javamoney.examples.ez.money.importexport;

import static org.javamoney.examples.ez.money.ApplicationProperties.UI_CURRENCY_SYMBOL;
import static org.javamoney.examples.ez.money.ApplicationProperties.getCSVColumnOrder;
import static org.javamoney.examples.ez.money.importexport.CSVColumnKeys.AMOUNT;
import static org.javamoney.examples.ez.money.importexport.CSVColumnKeys.CHECK_NUMBER;
import static org.javamoney.examples.ez.money.importexport.CSVColumnKeys.DATE;
import static org.javamoney.examples.ez.money.importexport.CSVColumnKeys.NOTES;
import static org.javamoney.examples.ez.money.importexport.CSVColumnKeys.PAYEE;
import static org.javamoney.examples.ez.money.importexport.CSVConstants.QUOTE;
import static org.javamoney.examples.ez.money.importexport.CSVConstants.SEPARATOR;
import static org.javamoney.examples.ez.money.model.dynamic.transaction.TransactionTypeKeys.EXPENSE;
import static org.javamoney.examples.ez.money.model.dynamic.transaction.TransactionTypeKeys.INCOME;
import static org.javamoney.examples.ez.money.model.dynamic.transaction.TransactionTypeKeys.TRANSFER;
import static org.javamoney.examples.ez.money.utility.TransactionHelper.isExpense;

import java.io.BufferedReader;
import java.util.Date;
import java.util.StringTokenizer;

import org.javamoney.examples.ez.money.model.persisted.transaction.Transaction;
import org.javamoney.moneta.Money;

/**
 * This class facilitates extracting transactions from a CSV file.
 */
final class CSVTransactionExtracter extends TransactionExtracter {
	/**
	 * Constructs a new transaction extractor.
	 */
	protected CSVTransactionExtracter() {
		setColumnOrder(getCSVColumnOrder());
	}

	/**
	 * This method extracts and returns the next transaction from the stream. If
	 * there are no more transactions in the stream, then null is returned.
	 * 
	 * @param stream
	 *            The input stream that has the transactions.
	 * 
	 * @return The next transaction or null if there are no more transactions in
	 *         the stream.
	 * 
	 * @throws Exception
	 *             If an error occurs.
	 */
	@Override
	protected Transaction next(BufferedReader stream) throws Exception {
		Transaction trans = null;
		double amount = 0.0;
		Date date = new Date();
		String line = "";
		String notes = "";
		String number = "";
		String payee = "";

		setType(null);

		if ((line = stream.readLine()) != null) {
			StringTokenizer tokens = new StringTokenizer(line, SEPARATOR, true);
			int column = 0;

			while (tokens.hasMoreTokens() == true
					&& column < getColumnOrder().length) {
				int ordinal = getColumnOrder()[column]; // Get column mapping.

				line = getNextToken(tokens);

				if (ordinal == AMOUNT.ordinal()) {
					amount = extractAmount(line);

					// Don't change the type if it is already a transfer.
					if (getType() == null) {
						if (isExpense(amount) == true) {
							setType(EXPENSE);
						} else {
							setType(INCOME);
						}
					}
				} else if (ordinal == CHECK_NUMBER.ordinal()) {
					number = extractCheckNumber(line);
				} else if (ordinal == DATE.ordinal()) {
					date = extractDate(line);
					System.out.println(date);
				} else if (ordinal == NOTES.ordinal()) {
					notes = extractNotes(line);
				} else if (ordinal == PAYEE.ordinal()) {
					// Can be either a payee or an account.
					if (isAccount(line) == true) {
						payee = extractAccount(line);
						setType(TRANSFER);
					} else {
						payee = extractPayee(line);
					}
				} else {
					// Undefined ordinal. For now it is ignored.
				}

				column += 1;
			}

			// Create the transaction and assume it is reconciled.
			trans = new Transaction(number, date, payee, Money.of(amount,
					UI_CURRENCY_SYMBOL.getCurrency()), "", notes);
			trans.setIsReconciled(true);
		}

		return trans;
	}

	// ////////////////////////////////////////////////////////////////////////////
	// Start of private methods.
	// ////////////////////////////////////////////////////////////////////////////

	private int[] getColumnOrder() {
		return itsColumnOrder;
	}

	private String getNextToken(StringTokenizer tokens) {
		String token = tokens.nextToken();

		// If the next token is a token, then there was no data.
		if (token.equals(SEPARATOR) == true) {
			token = "";
		} else {
			// This indicates the delimiter needs to be included in the field
			// value.
			if (token.startsWith(QUOTE) == true) {
				// The delimiter was not in the token, so remove the quotes.
				if (token.endsWith(QUOTE) == true) {
					token = token.substring(1, token.length() - 1);
				} else {
					token = token.substring(1); // Remove the first quote.

					// Keep appending the tokens until the last quote is found.
					while (tokens.hasMoreTokens() == true) {
						token += tokens.nextToken();

						if (token.endsWith(QUOTE) == true) {
							break;
						}

						// Append the token that is supposed to be there.
						token += SEPARATOR;
					}

					// The token should end in a quote, so remove it. If not,
					// then the
					// data is invalid.
					if (token.endsWith(QUOTE) == true) {
						token = token.substring(0, token.length() - 1);
					}
				}
			}

			// The token delimiters are being returned and need to be removed
			// for the
			// next iteration. This is necessary to identify empty fields.
			if (tokens.hasMoreTokens() == true) {
				tokens.nextToken();
			}
		}

		return token.trim();
	}

	private void setColumnOrder(int[] values) {
		itsColumnOrder = values;
	}

	// ////////////////////////////////////////////////////////////////////////////
	// Start of class members.
	// ////////////////////////////////////////////////////////////////////////////

	private int[] itsColumnOrder;
}