java获取当前日期等以及时区

	public static void main(String[] args) throws Exception{
		/*
		 * 获取当前时间的办法
		 */
		//这个获取从1970年。。直到现在的毫秒数，可以用来计算程序执行时间(开头结尾各打个记号);
		System.currentTimeMillis();
		java.util.Date d = new java.util.Date();
		Calendar c = Calendar.getInstance();
		
		/*
		 * 将String转化为date类型
		 * public static Timestamp valueOf(String s)
		 * s - timestamp in format yyyy-[m]m-[d]d hh:mm:ss[.f...]. The fractional seconds may be omitted. 
		 * The leading zero for mm and dd may also be omitted.
		 */
		String s = "1970-12-30 08:24:37.56";
		Timestamp ts = Timestamp.valueOf(s);	
		System.out.println(ts);
		
		/*
		 * TimeZone时区处理，比如拿到日本现在hour：
		 * ID - 实现定义好的各种各样的字符串；
		 * public static TimeZone getTimeZone(String ID)
		 * ID - the ID for a TimeZone, either an abbreviation(缩写) such as "PST", 
		 * a full name such as "America/Los_Angeles", or a custom ID such as "GMT-8:00".
		 */
		Calendar cJapan = new GregorianCalendar(TimeZone.getTimeZone("Japan"));
		System.out.println(cJapan.get(Calendar.HOUR_OF_DAY));
		
		//查看那些timeZone ID可用：
		for(String str : TimeZone.getAvailableIDs()){
			System.out.println(str);
		}
	}