Java如何转换protobuf-net中的bcl.DateTime对象

一、定义DateTime Message

参考文档：https://github.com/mgravell/protobuf-net/blob/master/src/Tools/bcl.proto

message DateTime
{
optional sint64 value = 1; // the offset (in units of the selected scale) from 1970/01/01
optional TimeSpanScale scale = 2 [default = DAYS]; // the scale of the timespan

enum TimeSpanScale
{
DAYS = 0;
HOURS = 1;
MINUTES = 2;
SECONDS = 3;
MILLISECONDS = 4;
TICKS = 5;

MINMAX = 15; // dubious
}
}

DateTime中包含两个属性：value，TimeSpanScale；
value为时间值，TimeSpanScale为时间模数：秒、微秒、毫微妙、Ticks；
Ticks是.net中的计时周期，参考：https://msdn.microsoft.com/zh-cn/library/system.datetime.ticks.aspx
1ticks=100毫微妙，10000ticks=1毫秒；

二、生成对应的Java类

protoc.exe -I=d:/tmp --java_out=d:/tmp d:/tmp/date_time.proto

三、解析C#DateTime为Java的java.util.Date

public class DateTimeUtil {

private final static long TICKS_PER_MILLISECOND = 10000;

/**
* 将C#中的DateTime类型转为Java中的Date
*
* @param bclDateTime
* @return
*/
public final static Date fromDateTimeToDate(DateTime dateTime) {
long timeLong = dateTime.getValue();

DateTime.TimeSpanScale timeSpanScale = dateTime.getScale();

Calendar c = Calendar.getInstance();
TimeZone.setDefault(TimeZone.getTimeZone("UTC"));

switch (timeSpanScale) {
case DAYS:
// 24 * 60 * 60 * 1000
c.setTimeInMillis(timeLong * 86400000);
return c.getTime();
case HOURS:
// 60 * 60 * 1000
c.setTimeInMillis(timeLong * 3600000);
return c.getTime();
case MINUTES:
// 60 * 1000
c.setTimeInMillis(timeLong * 60000);
return c.getTime();
case SECONDS:
c.setTimeInMillis(timeLong * 1000);
return c.getTime();
case MILLISECONDS:
c.setTimeInMillis(timeLong);
return c.getTime();
case TICKS:
c.setTimeInMillis(timeLong / TICKS_PER_MILLISECOND);
return c.getTime();
default:
c.setTimeInMillis(0L);

return c.getTime();
}
}
}

参考文档：http://www.cnblogs.com/cuyt/p/6141723.html