一般用于记录方法所用时间 

import android.os.SystemClock;import java.util.HashMap;/** * * 用于方便的记录当前与开始时间的差值 * Created by wangxingsheng on 16/8/16. */public class TimeRecordUtil {    private static final String TAG = "TimeRecordUtil ";    private HashMap
    
      timeMap = new HashMap();    /**     * 记录当前时间为开始时间     * @param flag 作为标记存储     */    public long regist(int flag){        long startTime = SystemClock.elapsedRealtime();        timeMap.put(flag,startTime);        return startTime;    }    /**     * 获取当前时间与开始时间的差值     * @param flag 存储标记     * @return 如果返回-1,说明当前标记没有记录开始时间     */    public long getDifference(int flag){        if(timeMap.containsKey(flag)){            long endTime = SystemClock.elapsedRealtime();            long diff = endTime - timeMap.get(flag);            return diff;        }        return -1;    }    /**     * 自带log的开始记录     * @param flag     * @param LogTag     */    public long regist(int flag,String LogTag){        long time = regist(flag);        LogUtils.SystemOut(TAG+LogTag," regist flag = " + flag + " time " +time);        return time;    }    /**     * 自带log的获取差值     * @param flag     * @param LogTag     * @return     */    public long getDifference(int flag,String LogTag){        long time = getDifference(flag);        LogUtils.SystemOut(TAG+LogTag," differece flag = " + flag + " time " +time);        return time;    }}