Java DateFormat setTimeZone()方法及示例

DateFormat类中 的 setTimeZone() 方法用于设置该DateFormat的日历时区。

语法

public void setTimeZone(TimeZone time_zone)

**参数 **：该方法需要一个时区类型的参数time_zone，指的是新的时区。

返回值 ：该方法不返回任何值。

下面的程序说明了DateFormat类的setTimeZone()方法的工作原理：
例1 :

// Java code to illustrate
// getTimeZone() method
  
import java.text.*;
import java.util.*;
  
public class DateFormat_Demo {
    public static void main(String[] argv)
    {
        // Initializing the first formatter
        DateFormat DFormat
            = DateFormat.getDateInstance();
  
        // Converting the dateformat to string
        String str = DFormat.format(new Date());
  
        // Original TimeZone
        System.out.println(
            "The original timezone is: "
            + DFormat.getTimeZone()
                  .getDisplayName());
  
        TimeZone time_zone
            = TimeZone.getTimeZone("GMT");
  
        // Modifying the time zone
        DFormat.setTimeZone(time_zone);
  
        // Getting the modified timezones
        System.out.println(
            "New TimeZone is: "
            + DFormat.getTimeZone()
                  .getDisplayName());
    }
}

输出:

The original timezone is: Coordinated Universal Time
New TimeZone is: Greenwich Mean Time

例2 :

// Java code to illustrate
// getTimeZone() method
  
import java.text.*;
import java.util.*;
  
public class DateFormat_Demo {
    public static void main(String[] argv)
    {
        // Initializing the first formatter
        DateFormat DFormat
            = DateFormat.getDateInstance();
  
        // Converting the dateformat to string
        String str = DFormat.format(new Date());
  
        // Original TimeZone
        System.out.println(
            "The original timezone is: "
            + DFormat.getTimeZone()
                  .getDisplayName());
  
        TimeZone time_zone
            = TimeZone.getTimeZone("Pacific/Tahiti");
  
        // Modifying the time zone
        DFormat.setTimeZone(time_zone);
  
        // Getting the modified timezones
        System.out.println(
            "New TimeZone is: "
            + DFormat.getTimeZone()
                  .getDisplayName());
    }
}

输出:

The original timezone is: Coordinated Universal Time
New TimeZone is: Tahiti Time

参考资料: https://docs.oracle.com/javase/7/docs/api/java/text/DateFormat.html#setTimeZone(java.util.TimeZone)