Example of Java 6/7 threaf safety issue with SimpleDateFormat.

JavaDateThreadSafetyExample.java

package com.yuri.java8.time;

import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * Created by yuri.zelikov on 1/11/2016.
 */
public class JodaDateThreadSafetyExample {

    private static final DateTimeFormatter sdf = DateTimeFormat.forPattern("HH:mm:ss dd.MM.yyyy");

    public static void main(String[] args) {
        ExecutorService executor = Executors.newFixedThreadPool(100);
        while (true) {
            executor.submit((Runnable) JodaDateThreadSafetyExample::workConcurrently);
        }
    }

    public static void workConcurrently() {
        try {
            sdf.parseDateTime("19:30:55 03.05.2015");
            System.out.print("OK ");
        } catch (Throwable th) {
            System.out.println(th.getClass() + " : " + th.getMessage());
        }

    }
}