我正在尝试将语言环境时间转换为 UTC,然后将 UTC 转换为语言环境时间。但我没有得到结果。
public class DateDemo
{
public static void main(String args[])
{
DateFormat dateFormatter =
DateFormat.getDateTimeInstance
(DateFormat.SHORT, DateFormat.SHORT, Locale.getDefault());
TimeZone.setDefault(TimeZone.getDefault());
SimpleDateFormat simpleDateFormatter = new SimpleDateFormat("dd/MM/yyyy");
SimpleDateFormat simpleTimeFormatter = new SimpleDateFormat("hh:mm:ss a");
Date today = new Date();
String localeFormattedInTime = dateFormatter.format(today);
try
{
Date parsedDate = dateFormatter.parse(localeFormattedInTime);
System.out.println("Locale:" + localeFormattedInTime);
System.out.println("After parsing a date: " + parsedDate);
simpleDateFormatter.setTimeZone(TimeZone.getDefault());
simpleTimeFormatter.setTimeZone(TimeZone.getDefault());
String date = simpleDateFormatter.format(today);
String time = simpleTimeFormatter.format(today);
System.out.println("Today's only date: " + date);
System.out.println("Today's only time: " + time);
//// Locale to UTC converting
simpleDateFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
simpleTimeFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
String utcDate = simpleDateFormatter.format(today);
String utcTime = simpleTimeFormatter.format(today);
System.out.println("Convert into UTC's date: " + utcDate);
System.out.println("Convert into UTC's only time: " + utcTime);
//// UTC to locale converting
simpleDateFormatter.setTimeZone(TimeZone.getDefault());
simpleTimeFormatter.setTimeZone(TimeZone.getDefault());
Date getDate = simpleDateFormatter.parse(utcDate);
Date getTime = simpleTimeFormatter.parse(utcTime);
String getLocalDate = simpleDateFormatter.format(getDate);
String getLocalTime = simpleTimeFormatter.format(getTime);
System.out.println("Get local date: " + getLocalDate);
System.out.println("Get local time: " + getLocalTime);
} catch (ParseException e) {
e.printStackTrace();
}
}
}
我将本地日期和时间发送到网络服务,然后在需要时我需要检索 UTC 日期和时间,然后转换为区域设置日期和时间(即用户的本地设置)。
示例输出:
Locale:11/9/12 8:15 PM
After parsing a date: Fri Nov 09 20:15:00 SGT 2012
Today's only date: 09/11/2012
Today's only time: 08:15:30 PM
Convert into UTC's date: 09/11/2012
Convert into UTC's only time: 12:15:30 PM
Get local date: 09/11/2012
Get local time: 12:15:30 PM
<小时/>
在 Saksak 和 ADTC 回答后:
对于代码 fragment ,UTC 日期和时间(实际上是 GMT-5,因为数据库可能位于美国)是输入,我想获取本地日期和时间作为输出。但接下来的部分仍然给出GMT-5时间。
SimpleDateFormat simpleDateTimeFormatter = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss a");
....
Date inDateTime = simpleDateTimeFormatter.parse(intent.getExtras().getString("inTime")); Date outDateTime = simpleDateTimeFormatter.parse(intent.getExtras().getString("outTime"));
simpleDateTimeFormatter.setTimeZone(TimeZone.getDefault()); simpleDateTimeFormatter.setTimeZone(simpleDateTimeFormatter.getTimeZone());
//TimeZone tzTimeZone = TimeZone.getDefault();
//System.out.println("Current time zone: " + tzTimeZone.getDisplayName());
String getLocalInTimeString = simpleDateTimeFormatter.format(inDateTime);
String getLocalOutTimeString = simpleDateTimeFormatter.format(outDateTime);
我的问题:getLocalInTimeString
和 getLocalOutTimeString
仍然显示 GMT-5 计时。这是怎么回事?我还需要设置其他东西吗?
最佳答案
您需要执行以下操作来解决您的问题,您的代码将按此顺序转换回本地时间:
simpleDateFormatter.setTimeZone(TimeZone.getDefault());
simpleTimeFormatter.setTimeZone(TimeZone.getDefault());
Date getDate = simpleDateFormatter.parse(utcDate);
Date getTime = simpleTimeFormatter.parse(utcTime);
您需要做的是等待,直到将 utcDate、utcTime 字符串解析回日期对象 然后将日期格式化程序时区设置为本地时区,如下所示:
Date getDate = simpleDateFormatter.parse(utcDate);
Date getTime = simpleTimeFormatter.parse(utcTime);
simpleDateFormatter.setTimeZone(TimeZone.getDefault());
simpleTimeFormatter.setTimeZone(TimeZone.getDefault());
这应该打印本地正确的日期/时间。
编辑: 这是完整的主要方法:
public static void main(String[] args) {
DateFormat dateFormatter = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT, Locale.getDefault());
TimeZone.setDefault(TimeZone.getDefault());
SimpleDateFormat simpleDateFormatter = new SimpleDateFormat("dd/MM/yyyy");
SimpleDateFormat simpleTimeFormatter = new SimpleDateFormat("hh:mm:ss a");
Date today = new Date();
String localeFormattedInTime = dateFormatter.format(today);
try {
Date parsedDate = dateFormatter.parse(localeFormattedInTime);
System.out.println("Locale:" + localeFormattedInTime);
System.out.println("After parsing a date: " + parsedDate);
simpleDateFormatter.setTimeZone(TimeZone.getDefault());
simpleTimeFormatter.setTimeZone(TimeZone.getDefault());
String date = simpleDateFormatter.format(today);
String time = simpleTimeFormatter.format(today);
System.out.println("Today's only date: " + date);
System.out.println("Today's only time: " + time);
//// Locale to UTC converting
System.out.println("TimeZone.getDefault() >>> " + TimeZone.getDefault());
simpleDateFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
simpleTimeFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
String utcDate = simpleDateFormatter.format(today);
String utcTime = simpleTimeFormatter.format(today);
System.out.println("Convert into UTC's date: " + utcDate);
System.out.println("Convert into UTC's only time: " + utcTime);
//// UTC to locale converting
/**
** //////EDIT
*/
// at this point your utcDate,utcTime are strings that are formated in UTC
// so first you need to parse them back to Dates using UTC format not Locale
Date getDate = simpleDateFormatter.parse(utcDate);
Date getTime = simpleTimeFormatter.parse(utcTime);
// NOW after having the Dates you can change the formatters timezone to your
// local to format them into strings
simpleDateFormatter.setTimeZone(TimeZone.getDefault());
simpleTimeFormatter.setTimeZone(TimeZone.getDefault());
String getLocalDate = simpleDateFormatter.format(getDate);
String getLocalTime = simpleTimeFormatter.format(getTime);
System.out.println("Get local date: " + getLocalDate);
System.out.println("Get local time: " + getLocalTime);
} catch (ParseException e) {
e.printStackTrace();
}
}
关于java - 将本地日期和时间转换为 UTC,然后将 UTC 转换为本地日期和时间,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13307724/