ThreadLocalDemo.java

package ch4.s3;

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 {
    private static ThreadLocal<SimpleDateFormat> t1 = new ThreadLocal<SimpleDateFormat>();
    public static class ParseDate implements Runnable{
        int i=0;
        public ParseDate(int i){this.i=i;}

        public void run() {
            try{
                if(t1.get()==null){
                    t1.set(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
                }
                Date t =t1.get().parse("2015-03-29 19:29:"+i%60);
                System.out.println(i+":"+t);
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }
    }
    public static void main(String []args){
        ExecutorService es = Executors.newFixedThreadPool(10);
        for(int i=0;i<1000;i++){
            es.execute(new ParseDate(i));
        }
    }
}