Use of synchronized in constructor for accessing static SimpleDateFormat

Question

Just a little confused. I have
private static final SimpleDateFormat dateFormat = new SimpleDateFormat(pattern);
in my class. I made dateFormat static final, because its a costly operation that I dont want to do more than once. I access dateFormat in the constructor of my class to format a date. Since SimpleDateFormat is not threadsafe, my understanding is the access has to happen in synchronized block to ensure thread-safety, as follows
public MyClass (date) {
synchronized(dateFormat) {
dateFormat.format(new Date());
Is that right? I know that constructors dont need to be synchronized because they are object creations, hence cant have multiple threads stepping on one another. But since dateFormat is a static field, doesnt it need to be protected, inspite of the above argument? Would appreciate responses/comments. Thanks

Answer 1

this constructor constructs a log record and uses the dateformatter to add timestamp to the log. It is executed very frequently. My tests indicate that using a static dateformatter is better performing than using a new formatter per thread. I am including the results below. 'u method' stands for unsynchronized (new formatter for each thread) and 's method' for synchronized (with static formatter)
run completed, took [ 10] milliseconds to format date, using 'u method' for [ 1] threads
run completed, took [ 0] milliseconds to format date, using 's' method for [ 1] threads
run completed, took [ 10] milliseconds to format date, using 'u method' for [ 10] threads
run completed, took [ 0] milliseconds to format date, using 's' method for [ 10] threads
run completed, took [ 40] milliseconds to format date, using 'u method' for [ 50] threads
run completed, took [ 30] milliseconds to format date, using 's' method for [ 50] threads
run completed, took [ 70] milliseconds to format date, using 'u method' for [ 100] threads
run completed, took [ 40] milliseconds to format date, using 's' method for [ 100] threads
run completed, took [ 260] milliseconds to format date, using 'u method' for [ 500] threads
run completed, took [ 170] milliseconds to format date, using 's' method for [ 500] threads
run completed, took [ 491] milliseconds to format date, using 'u method' for [ 1000] threads
run completed, took [ 310] milliseconds to format date, using 's' method for [ 1000] threads
run completed, took [ 1793] milliseconds to format date, using 'u method' for [ 5000] threads
run completed, took [ 1472] milliseconds to format date, using 's' method for [ 5000] threads
run completed, took [ 3164] milliseconds to format date, using 'u method' for [ 10000] threads
run completed, took [ 2524] milliseconds to format date, using 's' method for [ 10000] threads
run completed, took [ 14571] milliseconds to format date, using 'u method' for [ 50000] threads
run completed, took [ 12819] milliseconds to format date, using 's' method for [ 50000] threads
run completed, took [ 28050] milliseconds to format date, using 'u method' for [ 100000] threads
run completed, took [ 25107] milliseconds to format date, using 's' method for [ 100000] threads