Concurrent Simple Date Format Example

gistfile1.txt

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @author Andre Luis de Oliveira Dias
 * @date 11/04/2014
 * http://www.javacodegeeks.com/2010/07/java-best-practices-dateformat-in.html
 */
public class ConcurrentSimpleDateFormat {

    private static final Logger logger = LoggerFactory.getLogger(ConcurrentSimpleDateFormat.class);

    private static final ThreadLocal<SimpleDateFormat> df = new ThreadLocal<SimpleDateFormat> () {

        @Override
        public SimpleDateFormat get() {
            return super.get();
        }

        @Override
        protected SimpleDateFormat initialValue() {
            return new SimpleDateFormat("yyyy-MM-dd");
        }

        @Override
        public void remove() {
            super.remove();
        }

        @Override
        public void set(SimpleDateFormat value) {
            super.set(value);
        }
    };

    /**
     *
     * @param dateString
     * @param formatPattern
     * @return
     * @throws ParseException
     */
    public static Date parse(String dateString, String formatPattern) {
        return parse(dateString, formatPattern, false);
    }

    /**
     *
     * @param dateString
     * @param formatPattern
     * @return
     * @throws ParseException
     */
    public static Date parseWithException(String dateString, String formatPattern) {
        return parse(dateString, formatPattern, true);
    }

    /**
     *
     * @param dateString
     * @param formatPattern
     * @param withExceptionDetails
     * @return
     */
    private static Date parse(String dateString, String formatPattern, boolean withExceptionDetails) {

        if (dateString != null) {
            try {
                SimpleDateFormat syncSdf = df.get();
                syncSdf.setLenient(false); // http://www.accordess.com/wpblog/techtip-use-of-setlenient-method-on-simpledateformat/
                syncSdf.applyPattern(formatPattern);
                return syncSdf.parse(dateString);

            } catch (Exception e) {
                logger.error("Error during date parsing with pattern: " + formatPattern + " and date: " + dateString + ". Reason: " + e.getMessage());

                if (withExceptionDetails) {
                    throw new RuntimeException(e);
                }
            }
        }

        return null;
    }

    /**
     *
     * @param date
     * @param formatPattern
     * @return
     * @throws ParseException
     */
    public static String format(Date date, String formatPattern) {
        return format(date, formatPattern, false);
    }

    /**
     *
     * @param date
     * @param formatPattern
     * @return
     * @throws ParseException
     */
    public static String formatWithException(Date date, String formatPattern) {
        return format(date, formatPattern, true);
    }

    /**
     *
     * @param date
     * @param formatPattern
     * @param withExceptionDetails
     * @return
     */
    private static String format(Date date, String formatPattern, boolean withExceptionDetails) {

        if (date != null) {
            try {
                SimpleDateFormat syncSdf = df.get();
                syncSdf.setLenient(false); // http://www.accordess.com/wpblog/techtip-use-of-setlenient-method-on-simpledateformat/
                syncSdf.applyPattern(formatPattern);
                return syncSdf.format(date);

            } catch (Exception e) {
                logger.error("Error during date formatting with pattern: " + formatPattern + " and date: " + date + ". Reason: " + e.getMessage());

                if (withExceptionDetails) {
                    throw new RuntimeException(e);
                }
            }
        }

        return null;
    }

    public static void main (String[] args) throws Exception {
        // EXAMPLES
        final String[] patterns = new String[] {"dd/MM/yyyy", "dd-MM-yyyy", "yyyy-MM-dd"};

        for (int i = 0; i < 1000; i++) {

            for (int x = 0; x < 3; x++) {
                logger.info("Formatting with " + patterns[x] + " = " + ConcurrentSimpleDateFormat.format(new Date(), patterns[x]));
            }
        }
    }
}

Utility class for concurrent usage of java.text.SimpleDateFormat, with exception detail handling.

Lenient added.