How do you convert time based on time zone in Java?

Java provides the classes java.util.TimeZone and java.util.Calendar for converting time zones and times.

Firstly, you need to obtain the required time zone object by using the static method getTimeZone(String ID) from the TimeZone class. For example, to obtain the time zone object for New York, USA, you can use the following code:

TimeZone timeZone = TimeZone.getTimeZone("America/New_York");

Then, you can use the Calendar class for time conversion. The Calendar class provides a few methods to set time zones, get current time, and so on. Below is an example code:

// 创建一个Calendar对象，并设置时区为美国纽约
Calendar calendar = Calendar.getInstance();
calendar.setTimeZone(timeZone);

// 获取当前时间
Date currentDate = new Date();
calendar.setTime(currentDate);

// 进行时区转换，例如转换为中国北京时间
TimeZone chinaTimeZone = TimeZone.getTimeZone("Asia/Shanghai");
calendar.setTimeZone(chinaTimeZone);

// 获取转换后的时间
Date chinaDate = calendar.getTime();

With the code above, you can now convert time based on time zones.