Printing user input from a copy constructor (java)

I am new to java and cannot figure out how to work the copy constructors. Please bear with me.

I am trying to get information for shipping packages. I am trying to use the copy constructor to repeat the enter shipping details section.

I honestly have no idea what to do with it. The code works fine for one package and there are no errors - I just need to figure out how to prompt a user for a second package.

import java.util.Scanner;

public class Package {
	
	private static double length = 1.0;
	private static double width = 1.0;
	private static double height = 1.0;
		
	private static double sum1 = length+width+height;
	
		public Package(Package p) {
		this.height = p.height;
		this.length = p.length;
		this.width = p.width;
			}
	
	
	public static void main(String[] args) {
		
		Scanner input = new Scanner(System.in);
		
		System.out.println("Enter package dimensions.\nEnter Length: ");
		length = input.nextDouble(); 
	
		System.out.println("\nEnter Width: ");
		width = input.nextDouble();
	
		System.out.println("\nEnter Height: ");
		height = input.nextDouble();

	
	
		System.out.println("Package 1: " + length + " X " + width + " X " + height + ", Volume = " + sum1);
	
	}
	
}

You can use do-while for this .. something like below

Scanner input = new Scanner(System.in);
    int i=0;
do{
        Package package =new Package();
    System.out.println("Enter package dimensions.\nEnter Length: ");
    package.length = input.nextDouble(); 

    System.out.println("\nEnter Width: ");
    package.width = input.nextDouble();

    System.out.println("\nEnter Height: ");
    package.height = input.nextDouble();



    System.out.println("Package : " + package.length + " X " + package.width + " X " + package.height + ", package.Volume = " + sum1);
i++;
}while ( i<=5);

I think your misunderstanding is in this line:

private static double sum1 = length+width+height;

This computation will be executed at the moment the runtime executes this line so when the class is loaded (so length=1.0, width=1.0, height=1.0).

If you want the sum to be calculated after you have set the length, width and height, you have to put the calculation in a method:

public static double sum() {
return length+width+height;
}

And in your last line call this method:

System.out.println("Package 1: " + length + " X " + width + " X " + height + ", Volume = " + sum())

Also notice that all your variables are static so you don't really use the Package as an object. For simplicity you can remove the constructor except if you want to learn about java objects but then you have to adapt more code.

UPDATE: this works but to be able to use the copy constructor I each time have to create 2 objects. Speaking of overhead.
Mathimatics: it is not sum but product for volumes.

import java.util.Scanner;
public class Package {
double length=1.0;
double height=1.0;
double width=1.0;
double sum;
public Package() {
}
public Package (Package p)
{
this.length = p.length;
this.height = p.height;
this.width = p.width;
// to calculate the volume it's more like a product then a sum
sum=length*height*width;
}
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
for (int i=0;i<5;i++)
{
Package pack=new Package();
System.out.println("Enter package dimensions.\nEnter Length: ");
pack.length = input.nextDouble(); 
System.out.println("\nEnter Width: ");
pack.width = input.nextDouble();
System.out.println("\nEnter Height: ");
pack.height = input.nextDouble();
Package p=new Package(pack);
System.out.println("Package 1: " + p.length + " X " + p.width + " X " + p.height + ", Volume = " + p.sum);
}
}
}