Difference between SimpleDateFormat and DateTimeFormatter

SimpleDateFormat and DateTimeFormatter are both classes in Java used for formatting and parsing date and time values, but they have some key differences:

1. Thread Safety:
   • SimpleDateFormat is not thread-safe. If multiple threads are trying to format or parse dates simultaneously using the same instance of SimpleDateFormat, it can lead to unexpected results.
   • DateTimeFormatter is designed to be thread-safe. Instances of DateTimeFormatter can be safely shared among multiple threads.
2. Immutability:
   • SimpleDateFormat is mutable, meaning its state can be modified after creation. This can lead to issues in a multithreaded environment.
   • DateTimeFormatter is immutable. Once you create an instance, its state cannot be changed. This makes it safe to use in concurrent scenarios.
3. Pattern Letters:
   • SimpleDateFormat uses pattern letters that are not always intuitive (e.g., ‘D’ for day of the year, ‘F’ for day of the week in month).
   • DateTimeFormatter uses a more comprehensive and consistent set of pattern letters based on the ISO 8601 standard. For example, ‘M’ is always used for month, ‘d’ for day of the month, and ‘E’ for day of the week.
4. API Design:
   • SimpleDateFormat is part of the older java.text package.
   • DateTimeFormatter is part of the newer java.time.format package introduced in Java 8 as part of the java.time API.
5. Handling of Locale:
   • Both classes allow you to specify a locale, but the way they handle it can differ.
   • SimpleDateFormat relies heavily on the default locale of the JVM unless explicitly set.
   • DateTimeFormatter allows you to explicitly set the desired locale or use the default locale.

In summary, if you are working with Java 8 or newer, it’s generally recommended to use DateTimeFormatter due to its thread safety, immutability, and improved API design. If you are working with older versions of Java, you may need to use SimpleDateFormat but be cautious about its lack of thread safety.

Create a file with a specific timestamp in its name in Java using the java.nio.file package along with the java.text and java.util packages for formatting the timestamp.