我是新来的班级之类的东西。我现在要做的就是使库存容纳一个物料,然后在工作时,我将研究如何制作多个物料对象以及如何使程序继续运行,以便“编辑”和“删除”方法工作。因此,基本上,这是对库存和物品项目的测试。
库存类别: 当我运行项目并输入一个字符串:(S1)时,它告诉我:
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:864)
at java.util.Scanner.next(Scanner.java:1485)
at java.util.Scanner.nextInt(Scanner.java:2117)
at java.util.Scanner.nextInt(Scanner.java:2076)
at inventory.items.Inventory.add(Inventory.java:24)
at inventory.items.Inventory.main(Inventory.java:98)
请记住,我是一个初学者,您告诉我的任何事情都会有所帮助。我似乎无法弄清楚此代码是否正常工作。
public class Inventory extends Item implements Actions{
int num1, num2;
String S1;
Item a = new Item();
Item b = new Item();
Scanner Sc = new Scanner(System.in);
@Override
public void add() {
System.out.println("Please enter the new item specifications as follows: 1. Quantity 2. Name 3. Price");
num1 = Sc.nextInt();
a.setQuantity(num1);
S1 = Sc.nextLine();
a.setName(S1);
num2 = Sc.nextInt();
a.setPrice(num2);
}
/**
*
* @param b
*/
@Override
public void remove(Item b) {
b = null;
System.gc();
}
/**
*
* @param E
*/
@Override
public void edit(String E) {
E = Sc.nextLine();
if(a.getName().equals(b)){
System.out.println("Please edit the item specifications as follows: 1. Quantity 2. Name 3. Price ");
num1 = Sc.nextInt();
S1 = Sc.nextLine();
num2 = Sc.nextInt();
a.setQuantity(num1);
a.setName(S1);
a.setPrice(num2);
}
else{
System.out.println("You can't edit a non existent item. The items are case
sensitive.");
}
}
/**
*
* @param Info
*/
@Override
public void info(String Info) {
if(a.getName().equals(Info)){
System.out.println("Item name : " + a.getName() + " Item price: " +
a.getPrice() + " Item Quantity: " + a.getQuantity());
}
else{
System.out.println("Please enter a an existing item name!");
}
}
public static void main (String [] args){
Inventory inv = new Inventory();
Scanner Sc1 = new Scanner(System.in);
Item a = new Item();
Item b = new Item();
String I = "";
System.out.println("Please enter one of the following commands: 1. add 2.
edit 3. remove 4. info ");
I = Sc1.nextLine();
switch (I){
case "add" :
inv.add();
break;
case "edit" :
System.out.println("Enter the name of the item you want to edit: ");
String Input2 = Sc1.nextLine();
inv.edit(Input2);
break;
case "remove" :
System.out.println("Enter the name of the item you want to remove: ");
inv.remove(a);
break;
case "info" :
System.out.println("Enter the name of the item you want too see its info.");
String Inf = Sc1.nextLine();
inv.info(Inf);
default :
System.out.println("Please enter a valid command! The commands ARE case-
sensitive.");
}
}
}
物品类别:
这是库存类的超类。我正在使用getter和setter在其中设置新对象的值。
class Item{
private int q,p;
private String n;
private int quantity = 0;
private String name = " ";
private int price = 0;
public void setQuantity(int q){
this.quantity = q;
}
public int getQuantity(){
return q;
}
public void setName(String n){
this.name = n;
}
public String getName(){
return n;
}
public void setPrice(int p){
this.price = p;
}
public int getPrice(){
return p;
}
}
动作界面:
我正在使用此界面设置可以对Item对象进行的操作;更改其属性。
interface Actions {
void add();
void remove(Item b);
void edit(String E);
void info(String Info);
}
答案 0 :(得分:1)
https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#nextInt():
InputMismatchException-如果下一个标记与Integer正则表达式不匹配或超出范围
您已经在一个字符串中输入了期望的整数,这就是引发此异常的原因。请务必先阅读JavaDosc。这是您的第一个指针,它将帮助您消除大多数“我不知道”的错误。
检查您得到的输入!
答案 1 :(得分:0)
可能Scanner.next()
会解决您的问题,因为Scanner.nextInt()
只会读取int值而不是行尾,而Scanner.nextLine()
则会读取行尾并带有数字。
num1 = Sc.nextInt();
a.setQuantity(num1);
S1 = Sc.next();
a.setName(S1);
num2 = Sc.nextInt();
a.setPrice(num2);
或
只需添加Sc.nextLine()
即可读取行上带有数字的其余部分。
num1 = Sc.nextInt();
Sc.nextLine();
a.setQuantity(num1);
S1 = Sc.nextLine();
a.setName(S1);
num2 = Sc.nextInt();
a.setPrice(num2);
答案 2 :(得分:0)
获取num字段并输入后,下一行将由S1 = Sc.nextLine();读取。并且您正在尝试写入名称字段,但是num2 = Sc.nextInt();在跑。因此,您会遇到错误。