The parse method of SimpleDateFormat does not work, always throws
a NullPointerException.

The following test program has been copied from javadocs. It does not work.
It is not obvious to me what I am doing wrong.

import java.util.*;
import java.io.*;
import java.text.*;

public class Test {

public static void main(String[] args) {
SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, "PST");
        pdt.setStartRule(4, 1, 5, 2*60*60*1000);
        pdt.setEndRule(10, -1, 5, 2*60*60*1000);
        

        // Format the current time.
        SimpleDateFormat formatter
            = new SimpleDateFormat ("yyyyMMddHHmmss'Z'");
        Date currentTime_1 = new Date();
        String dateString = formatter.format(currentTime_1);

        // Parse the previous string back into a Date.
        ParsePosition pos = new ParsePosition(0);
        Date currentTime_2 = formatter.parse(dateString, pos);
}
}