Java获得UTC时间

java.util.Calendar cal = java.util.Calendar.getInstance();

java.util.TimeZone zone = java.util.TimeZone.getTimeZone(“GMT-8:00″);
java.util.Calendar cal = java.util.Calendar.getInstance(zone);

java.util.Calendar cal = java.util.Calendar.getInstance(java.util.Locale.CHINA);

java.util.Calendar cal = java.util.Calendar.getInstance();

int zoneOffset = cal.get(java.util.Calendar.ZONE_OFFSET);

int dstOffset = cal.get(java.util.Calendar.DST_OFFSET);

cal.add(java.util.Calendar.MILLISECOND, -(zoneOffset + dstOffset));

package com.feima.afei.util;

package com.feima.afei.util;

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

/**
 * 
 * @author Javen
 *
 */
public final class GetUTCTimeUtil {
    
    private static DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm") ;
    
    /**
     * 得到UTC时间，类型为字符串，格式为"yyyy-MM-dd HH:mm"<br />
     * 如果获取失败，返回null
     * @return
     */
    public static String getUTCTimeStr() {
        StringBuffer UTCTimeBuffer = new StringBuffer();
        // 1、取得本地时间：
        Calendar cal = Calendar.getInstance() ;
        // 2、取得时间偏移量：
        int zoneOffset = cal.get(java.util.Calendar.ZONE_OFFSET);
        // 3、取得夏令时差：
        int dstOffset = cal.get(java.util.Calendar.DST_OFFSET);
        // 4、从本地时间里扣除这些差量，即可以取得UTC时间：
        cal.add(java.util.Calendar.MILLISECOND, -(zoneOffset + dstOffset));
        int year = cal.get(Calendar.YEAR);
        int month = cal.get(Calendar.MONTH)+1;
        int day = cal.get(Calendar.DAY_OF_MONTH);
        int hour = cal.get(Calendar.HOUR_OF_DAY);
        int minute = cal.get(Calendar.MINUTE); 
        UTCTimeBuffer.append(year).append("-").append(month).append("-").append(day) ;
        UTCTimeBuffer.append(" ").append(hour).append(":").append(minute) ;
        try{
            format.parse(UTCTimeBuffer.toString()) ;
            return UTCTimeBuffer.toString() ;
        }catch(ParseException e)
        {
            e.printStackTrace() ;
        }
        return null ;
    }
    
    /**
     * 将UTC时间转换为东八区时间
     * @param UTCTime
     * @return
     */
    public static String getLocalTimeFromUTC(String UTCTime){
        java.util.Date UTCDate = null ;
        String localTimeStr = null ;
        try {
            UTCDate = format.parse(UTCTime);
            format.setTimeZone(TimeZone.getTimeZone("GMT-8")) ;
            localTimeStr = format.format(UTCDate) ;
        } catch (ParseException e) {
            e.printStackTrace();
        }
         
        return localTimeStr ;
    }
    
    public static void main(String[] args) { 
        String UTCTimeStr = getUTCTimeStr() ;
        System.out.println(UTCTimeStr); 
        System.out.println(getLocalTimeFromUTC(UTCTimeStr));
    }

}