get total RAM and available RAM in megabytes (mb)

RAMUtilities.java

import android.app.ActivityManager;
import android.content.Context;

import static android.content.Context.ACTIVITY_SERVICE;

public class RAMUtilities {
    
    public static long[] getRamInfo(Context context) {
        
        ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
        ActivityManager activityManager = (ActivityManager) context.getSystemService(ACTIVITY_SERVICE);
        if (activityManager != null) {
            activityManager.getMemoryInfo(mi);
        }
        return new long[]{
                mi.totalMem / 0x100000L, // total ram in mb
                mi.availMem / 0x100000L  // available ram in mb
        };
    }
}