Java学習–日付・時間の表示GMTとUTCの変換方法

2016年11月7日

Javaコード
package koko;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

public class CftTimeZone {

public static void main(String[] args) {
try {
String ts = “2016-10-23T17:15:44.000Z";
System.out.println(“ts = " + ts);
ts = ts.replace(“Z", " UTC");
System.out.println(“ts = " + ts);
SimpleDateFormat sdf = new SimpleDateFormat(“yyyy-MM-dd’T’HH:mm:ss.SSS Z");

Date dt = sdf.parse(ts);

TimeZone tz = sdf.getTimeZone();
Calendar c = sdf.getCalendar();
//System.out.println(“Display name: " + tz.getDisplayName());
System.out.println(getString(c));
} catch (ParseException pe) {
System.out.println(“Error offset: " + pe.getErrorOffset());
pe.printStackTrace();
}
}

private static String getString(Calendar c) {
StringBuffer result = new StringBuffer();
result.append(c.get(Calendar.YEAR));
result.append(“-“);
result.append((c.get(Calendar.MONTH) + 1));
result.append(“-“);
result.append(c.get(Calendar.DAY_OF_MONTH));
result.append(" “);
result.append(c.get(Calendar.HOUR_OF_DAY));
result.append(“:");
result.append(c.get(Calendar.MINUTE));
result.append(“:");
result.append(c.get(Calendar.SECOND));
return result.toString();
}
}

実行結果
ts = 2016-10-23T17:15:44.000Z
ts = 2016-10-23T17:15:44.000 UTC
2016-10-23 17:15:44