如何以毫秒精度获取日期差作为浮点数

Question

public static void main(String[] args) throws InterruptedException{
    long sTime =  new Date().getTime();
    Thread.sleep(3234);
    long eTime =  new Date().getTime();
    float diff = ((eTime-sTime)/1000);
    System.out.println(diff);
}

In the above code, I am expecting the output to be 3.234 but it is 3.0. I want the exact difference between two times in seconds, with a fractional part.

Answer 1

You are doing an integral division instead of a floating-point one. Try this:

float diff = ((float)(eTime-sTime)/1000.0);

As you are using long s, I further suggest you to use double datatype for greater precision:

double diff = ((double)(eTime-sTime)/1000.0);

Answer 2

    double sTime =  new Date().getTime();
    Thread.sleep(3234);
    double eTime =  new Date().getTime();
    double diff = ((eTime-sTime)/1000);
    System.out.println(diff);