#108

The reasons why Date toDate(String value) is not thread safe are:

• The static member variables dateFormat, datePattern will be initialized many times when multiple threads invoke this method.
• The method parse() of SimpleDateFormat is not thread safe.

In general, there are three ways to solve this problem.

• Option1. Introduce synchronized. Date toDate(String value) -> synchronized Date toDate(String value)
• Option2. Use eager instantiation for dateFormat and datePattern. Put SimpleDateFormat[] dateFormat in ThreadLocal.
• Option3. Use eager instantiation for dateFormat and datePattern. Introduce third party libraries JODA time and use DateTimeFormat.forPattern to format time.

I prefer Option1 since it has minimal impact on the original code. In most cases we don't have multithreaded access so it won't cause thread context switch.

The build failure here is very strange, I've sent an email to Travis CI support

I've fixed some Travis CI configuration on the develop branch, merge it into your branch and the tests should run properly again