解决SimpleDateFormat线程安全问题

import java.text.ParseException;
import java.text.SimpleDateFormat;
public class SimpleDateFormatDemo {
    // (1)创建单例实例
    static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    public static void test1() {
        // (2)创建多个线程，并启动
        for (int i = 0; i < 10; ++i) {
            Thread thread = new Thread(new Runnable() {
                @Override
                public void run() {
                    try {// (3)使用单例日期实例解析文本
                        System.out.println(sdf.parse("2019-03-07 15:17:27"));
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }
                }
            });
            thread.start();// (4)启动线程
        }
    }
    public static void main(String[] args) {
        test1();
    }
}

Exception in thread "Thread-5" Exception in thread "Thread-4" Exception in thread "Thread-0" java.lang.NumberFormatException: multiple points
  at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1890)
  at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)
  at java.lang.Double.parseDouble(Double.java:538)
  at java.text.DigitList.getDouble(DigitList.java:169)
  at java.text.DecimalFormat.parse(DecimalFormat.java:2089)
  at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1869)
  at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1514)
  at java.text.DateFormat.parse(DateFormat.java:364)
  at net.ijiangtao.tech.framework.spring.ispringboot.demo.demostart.thread.demo.SimpleDateFormatDemo$1.run(SimpleDateFormatDemo.java:18)

// (1)创建localDateFormat实例
  static ThreadLocal<DateFormat> localDateFormat = new ThreadLocal<DateFormat>() {
    @Override
    public SimpleDateFormat initialValue() {
      return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    }
  };
  public static void test() {
    // (2)创建多个线程，并启动
    for (int i = 0; i < 10; ++i) {
      Thread thread = new Thread(new Runnable() {
        public void run() {
          try {// (3)解析文本
            // System.out.println(sdf.parse("2019-03-07 15:17:27"));
            System.out.println(localDateFormat.get().parse("2019-03-07 15:17:27"));
          } catch (Exception e) {
            e.printStackTrace();
          }
        }
      });
      thread.start();// (4)启动线程
    }
  }
  public static void main(String[] args) {
    test();
  }