Java中的DateTime.FromOADate（）相当于什么（Java中的Datetime是Datetime的两倍）(What is the equivalent of DateTime.FromOADate() in Java (double to Datetime in Java))

 您是否意识到您的二进制数据是OLE自动化日期值的二进制抑制？ 
 
 所以不要long ，你应该从你的数组中获得一个double值。 
 
var b = new byte[8];
b[0] = 0x20;
b[1] = 0x64;
b[2] = 0xa8;
b[3] = 0xac;
b[4] = 0xb6;
b[5] = 0x65;
b[6] = 0xe4;
b[7] = 0x40;
var dbl = BitConverter.ToDouble(b, 0);
var dt = DateTime.FromOADate(dbl);
Console.WriteLine("{0:s}", dt);
 
 结果是： 
 
2014-05-14T17:00:21
 
 我认为这个有效的问题应该是： Java中的DateTime.FromOADate（）等价于什么？ 
 
 答案是： 
 
public static Date fromDoubleToDateTime(double OADate) 
{
    long num = (long) ((OADate * 86400000.0) + ((OADate >= 0.0) ? 0.5 : -0.5));
    if (num < 0L) {
        num -= (num % 0x5265c00L) * 2L;
    }
    num += 0x3680b5e1fc00L;
    num -=  62135596800000L;

    return new Date(num);
}

Did you realize that your binary data is the binary represantation of an OLE Automation date value? 
 
So instead of getting long, you should get a double value from your array. 
 
var b = new byte[8];
b[0] = 0x20;
b[1] = 0x64;
b[2] = 0xa8;
b[3] = 0xac;
b[4] = 0xb6;
b[5] = 0x65;
b[6] = 0xe4;
b[7] = 0x40;
var dbl = BitConverter.ToDouble(b, 0);
var dt = DateTime.FromOADate(dbl);
Console.WriteLine("{0:s}", dt);
 
Result is :
 
2014-05-14T17:00:21
 
I think the valid question should be: What is the equivalent of DateTime.FromOADate() in Java ?
 
Answer is:
 
public static Date fromDoubleToDateTime(double OADate) 
{
    long num = (long) ((OADate * 86400000.0) + ((OADate >= 0.0) ? 0.5 : -0.5));
    if (num < 0L) {
        num -= (num % 0x5265c00L) * 2L;
    }
    num += 0x3680b5e1fc00L;
    num -=  62135596800000L;

    return new Date(num);
}