package efficient_lock;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ThreadLocalDemo {
	static ThreadLocal<SimpleDateFormat> t1 = new ThreadLocal<>();

	public static void main(String[] args) {
		ExecutorService threadPool = Executors.newFixedThreadPool(10);
		for (int j = 0; j < 1000; j++) {
			threadPool.submit(new ParseDate(j));
		}
		threadPool.shutdown();
	}

	public static class ParseDate implements Runnable {
		int i = 0;

		public ParseDate(int i) {
			super();
			this.i = i;
		}

		@Override
		public void run() {
			if (t1.get() == null) {
				t1.set(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
			}
			try {
				Date t = t1.get().parse("2016-05-20 05:20:" + i % 60);
				System.out.println(i + ":" + t);
			} catch (ParseException e) {
				e.printStackTrace();
			}
		}
	}

}