「リソースリーク：「スキャン」は決して閉じられません」と表示される距離計算式

Question

import java.util.Scanner; 
//distance = square root of [(x2-x1)squared + (y2-y1)squared + (z2-z1)squared] 

public class FirstCode 
{ 
    static double distance(double x1, double y1, double z1, double x2, double y2, double z2) 
    { 
     return Math.sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1) + (z2-z1)*(z2-z1)); 
    } 

    public static void main(String[] args) 
    { 
     double x2, x1, y2, y1, z2, z1; 
     double distance; 

     Scanner scan = new Scanner (System.in); 

     System.out.println("Enter the x coordinate for point 1: "); 
     x1 = scan.nextDouble(); 

     System.out.println("Enter the y coordinate for point 1: "); 
     y1 = scan.nextDouble(); 

     System.out.println("Enter the x coordinate for point 2: "); 
     x2 = scan.nextDouble(); 

     System.out.println("Enter the y coordinate for point 2: "); 
     y2 = scan.nextDouble(); 

     System.out.println("Enter the z coordinate for point 3: "); 
     z1 = scan.nextDouble(); 

     System.out.println("Enter the z coordinate for point 3: "); 
     z2 = scan.nextDouble(); 
     distance = distance(x1,y1,x2,y2,z1,z2); 
     System.out.println("The distance between the two points is " + distance + " ."); 
    } 
} 

Answer 1

最後にスキャナを閉じるだけです。

scan.close();