How to get/calculate survivor space heap memory usage in Java?

Question

I want to get the survivor space memory capacity within a Java application. I have tried using ManagementFactory class to get survivor space capacity, but it only fetches the capacity of one of the survivor spaces.

When I use jstat, I get the following result (sizes are in MB, C -> capacity, U -> used):

S0C	S1C	S0U	S1U
56320.0	4608.0	0.0	4238.9

ManagementFactory.getMemoryPoolMXBeans() fetches only the capacity of the survivor space which is not-empty (in this case S1C).

Due to this, there's a difference between Xmx value and max heap calculated using ManagementFactory.getMemoryPoolMXBeans() method. And the difference is exactly the size of S0C.

This is the code for reference:

long survivorSpaceMax = 0L;

for (MemoryPoolMXBean mpBean : ManagementFactory.getMemoryPoolMXBeans()) {
    if (mpBean.getName().equals("Survivor Space") || mpBean.getName().equals("PS Survivor Space") {
        survivorSpaceMax = mpBean.getUsage().getMax(); // Returns the capacity of the non-empty survivor space
    }
}

Is the any other way to get the total of both the survivor space capacities?