Java如何格式化包含时间信息的消息？
在这里，我们演示如何使用java.text.MessageFormat该类来格式化包含时间信息的消息。
package org.nhooo.example.text;
import java.util.Date;
import java.util.Calendar;
import java.util.Locale;
import java.text.MessageFormat;
public class MessageFormatTime {
public static void main(String[] args) {
Date today = new Date();
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.HOUR, 7);
Date nextWeek = calendar.getTime();
//我们希望消息为Locale.US
Locale.setDefault(Locale.US);
//格式化包含日期信息的时间。
String message = MessageFormat.format("Now is {0} and the next " +
"7 hours is {1}", today, nextWeek);
System.out.println(message);
//格式化时间并仅显示时间部分
message = MessageFormat.format("Now is {0, time} and the next " +
"7 hours is {1, time}", today, nextWeek);
System.out.println(message);
//使用短格式（例如HH：mmam/pm）格式化时间
message = MessageFormat.format("Now is {0, time, short} and " +
"the next 7 hours is {1, time, short}", today, nextWeek);
System.out.println(message);
//使用中等格式（例如HH：mm：ssam/pm）格式化时间。
message = MessageFormat.format("Now is {0, time, medium} and " +
"the next 7 hours is {1, time, medium}", today, nextWeek);
System.out.println(message);
//使用长格式（例如HH：mm：ssam/pmTIMEZONE）格式化时间。
message = MessageFormat.format("Now is {0, time, long} and the " +
"next 7 hours is {1, time, long}", today, nextWeek);
System.out.println(message);
//使用完整格式（例如HH：mm：ssam/pmTIMEZONE）格式化时间。
message = MessageFormat.format("Now is {0, time, full} and the " +
"next 7 hours is {1, time, full}", today, nextWeek);
System.out.println(message);
//使用自定义模式设置时间格式。
message = MessageFormat.format("Now is {0, time, HH:mm:ss.sss} " +
"and the next 7 hours is {1, time, HH:mm:ss.sss}", today, nextWeek);
System.out.println(message);
}
}上面的程序产生：
Now is 2/15/18, 9:07 PM and the next 7 hours is 2/16/18, 4:07 AM Now is 9:07:26 PM and the next 7 hours is 4:07:26 AM Now is 9:07 PM and the next 7 hours is 4:07 AM Now is 9:07:26 PM and the next 7 hours is 4:07:26 AM Now is 9:07:26 PM CST and the next 7 hours is 4:07:26 AM CST Now is 9:07:26 PM China Standard Time and the next 7 hours is 4:07:26 AM China Standard Time Now is 21:07:26.026 and the next 7 hours is 04:07:26.026