Calculating distance between dots java

My task is to load coordinates from a file, and calculate perimeter of the shape.
example of dots.txt

-3, 9
-8, 7
-12, 4
-6, -2
-4, -6
2, -8
6, -5
10, -3
8, 5
4, 8

I have created a Dot.class which is quite simple, with an method to calculate distance between 2 dots.

public class Dot {
    int x;
    int y;

    public Dot(int x, int y)
    {
        this.x = x;
        this.y = y;
    }


    public double calcDistance(Dot anotherDot)
    {
        int dx = x - anotherDot.x;
        int dy = y - anotherDot.y;
        return Math.sqrt((dx*dx) + (dy*dy));
//EDIT: WORKS SAME AS
//return Math.hypot(x - anotherDot.x, y - anotherDot.y);
    }

    public String toString(){
        return "" + x + y;
    }
}

Here is my Main method:

import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws Exception {
        //read file
        FileReader fr = new FileReader("src/com/company/dots.txt");
        Scanner inFile = new Scanner(fr);
        ArrayList<Dot> dots = new ArrayList<>();

        while (inFile.hasNext())
        {
            // Read the next line.
            String [] line = inFile.nextLine().split(",");
            // Display the line.
            int x = Integer.parseInt(line[0]);
            int y = Integer.parseInt(line[1].replace(" ", ""));
            System.out.println(x + " " + y);
            dots.add(new Dot(x, y));
        }

        System.out.println("size of the ArrayList: " + dots.size());


        // Close the file.
        inFile.close();

    }
}

Please help me with calculating perimeter because I am pretty stuck with this one..
Thanks in advance

EDIT:
Managed to write a simple for-loop to calculate distance between dots and then sum it up.

int lastDot = dots.size() - 1;
double perimeter = 0;
    for(int i = 0; i< dots.size(); i++)
    {
//check if its the last dot, then calculate distance between the last dot and the first one.
        if(i==lastDot){ 
            perimeter += dots.get(lastDot).calcDistance(dots.get(0));
        } else
        perimeter += dots.get(i).calcDistance(dots.get(i+1));
    }

Have you tried something like:

double dist=0;
for(int i=0;i<dots.size();i++){
   dist+= dots.get(i%dots.size()).calcDistance((i+1)%dots.size());
}

or you mean something more complex like not having crossing of lines?

public static void main(String... args) throws FileNotFoundException {
List<Dot> dots = readData(new FileReader("src/com/company/dots.txt"));
System.out.println("size of the List: " + dots.size());
double perimeter = getShapePerimeter(dots);
System.out.format(Locale.ENGLISH, "shape perimeter: %.2f\n", perimeter);
}
private static List<Dot> readData(Reader reader) throws FileNotFoundException {
try (Scanner scan = new Scanner(reader)) {
scan.useDelimiter(",\\s*|\\n");
List<Dot> dots = new ArrayList<>();
while (scan.hasNext()) {
int x = scan.nextInt();
int y = scan.nextInt();
dots.add(new Dot(x, y));
}
return dots;
}
}
private static double getShapePerimeter(List<Dot> dots) {
double res = 0;
Dot prv = dots.get(dots.size() - 1);
for (Dot dot : dots) {
res += Math.hypot(dot.x - prv.x, dot.y - prv.y);
prv = dot;
}
return res;
}
public static final class Dot {
private final int x;
private final int y;
public Dot(int x, int y) {
this.x = x;
this.y = y;
}
}

Output:

size of the List: 10
shape perimeter: 59.46