如何将用户输入添加到Java程序中，以便在if语句中使用

我正在尝试将用户输入添加到我的类中，以便用户可以输入他们的包的重量，我的类将告诉他们这将花费他们多少。我对java非常陌生，所以我知道这并不令人惊讶，但这是我目前所能做到的最好的。提前谢谢

public class ShippingCosts {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int weight = 0;

        if (0 < weight && weight <= 1)
            System.out.println("The cost to ship the package is $3.50");
        if (1 < weight && weight <= 3)
            System.out.println("The cost to ship the package is $5.50");
        if (3 < weight && weight <= 10)
            System.out.println("The cost to ship the package is $9.50");
        if (10 < weight && weight <= 20)
            System.out.println("The cost to ship the package is $13.50");
        if (20 < weight)
            System.out.println("The package is too heavy to be shipped");

        System.out.println("How heavy is the package?");

    }

}

公共类运输成本{
公共静态void main（字符串[]args）{
//TODO自动生成的方法存根
整数权重=0；
如果（0
提示用户输入：

Scanner input = new Scanner(System.in);

System.out.println("Please enter your name : "); //prompt user
s = input.next(); // getting a String value

System.out.println("Please enter your age : ");
i = input.nextInt(); // getting an integer

System.out.println("Please enter your salary : ");
d = input.nextDouble(); // getting a double

所以我把它添加到我的代码中并导入了java.util.Scanner，但我仍然很困惑如何才能真正从这里获得用户输入。当我说我是java新手时，我的意思是我几天前就开始了，所以我需要一些时间才能变得更好。谢谢你的澄清！请在发布之前搜索堆栈溢出ng。
Scanner input = new Scanner(System.in);

System.out.println("Please enter your name : "); //prompt user
s = input.next(); // getting a String value

System.out.println("Please enter your age : ");
i = input.nextInt(); // getting an integer

System.out.println("Please enter your salary : ");
d = input.nextDouble(); // getting a double