时间转换封装 线程安全

为了有一个公用的时间处理工具，就封装了一个，该封装的工具是线程安全的，可以放心使用。

public class SafeDateFormat {    final static Map<String, ThreadLocal<DateFormat>> threadLocalPool = new HashMap<>();    final static ThreadLocal<DateFormat> DefaultThreadLocal = new ThreadLocal<DateFormat>() {        @Override        protected synchronized DateFormat initialValue() {            return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");        }    };    static {        threadLocalPool.put("yyyy-MM-dd HH:mm:ss", DefaultThreadLocal);    }    public static Date parse(String dateStr) throws ParseException {        return DefaultThreadLocal.get().parse(dateStr);    }    public static Date parse(final String format, String dateStr) throws ParseException {        ThreadLocal<DateFormat> threadLocal = threadLocalPool.get(format);        if (threadLocal == null) {            threadLocal = new ThreadLocal<DateFormat>() {                @Override                protected synchronized DateFormat initialValue() {                    return new SimpleDateFormat(format);                }            };            threadLocalPool.put(format, threadLocal);        }        return threadLocal.get().parse(dateStr);    }    public static String format(Date date) {        return DefaultThreadLocal.get().format(date);    }    public static String format(final String format, Date date) {        ThreadLocal<DateFormat> threadLocal = threadLocalPool.get(format);        if (threadLocal == null) {            threadLocal = new ThreadLocal<DateFormat>() {                @Override                protected synchronized DateFormat initialValue() {                    return new SimpleDateFormat(format);                }            };            threadLocalPool.put(format, threadLocal);        }        return threadLocal.get().format(date);    }