所以我正在写一个程序，我必须有一个游戏或电影项目列表。每个项目都有一个3位数的ID号（保存为字符串），标题，价格，股票支票（输入/输出）和租借者名称（名称或空白）。我必须有一个与这些项目有关的菜单项列表。 item类是抽象的，电影和游戏都扩展了它。这是电影商店代码：
import java.util.*;
import java.io.*;
public class MovieStore
{
private Item[] items=null;
private int numItems;
public MovieStore() //default constructor
{
items=new Item[30];
numItems=0;
}
public MovieStore(String testFileName) throws IOException
{
File f=new File(testFileName);
if(!f.exists())
{
System.out.println("File "+testFileName+" does not exist.");
System.exit(0);
}
Scanner input=new Scanner(f);
items=new Item[30];
numItems=0;
String code;
while (input.hasNext())
{
code=input.next();
if (code.equals("M"))
{
String id=input.next();
String title=input.next();
double price=input.nextDouble();
int runTime=input.nextInt();
String rating=input.next();
String format=input.next();
int stockcheck=input.nextInt();
String renter=input.next();
if (stockcheck==1) //true, in stock
items[numItems]=new Movie(id, title, price, true, runTime, rating, format);
else //false, not in stock
items[numItems]=new Movie(id, title, price, false, renter, runTime, rating, format);
}
else if (code.equals("G"))
{
String id=input.next();
String title=input.next();
double price=input.nextDouble();
int stockcheck=input.nextInt();
int ageLevel=input.nextInt();
String renter=input.next();
if (stockcheck==1) //true, in stock
items[numItems]=new Game(id, title, price, true, ageLevel);
else //false, not in stock
items[numItems]=new Game(id, title, price, false, renter, ageLevel);
}
numItems++;
}
SelectionSort.sort(items, numItems);
}
public int search(String id)
{
Item key=new Item(id, "", 0.0, true, "");
return (BinarySearch.search(items, numItems, key));
}
public void addItem(Item s)
{
items[numItems]=s;
numItems++;
SelectionSort.sort(items, numItems);
}
public static String menu()
{
String code="";
Scanner input=new Scanner(System.in);
System.out.println("Enter one of the following options as a letter.");
System.out.println("a. Check out an item.");
System.out.println("b. Check in an item.");
System.out.println("c. Search an item by ID to see if it is in stock.");
System.out.println("d. Search an item by name.");
System.out.println("e. Display inventory.");
System.out.println("f. Add a new item to the inventory.");
System.out.println("g. Delete an item from the inventory.");
System.out.println("h. Display the menu.");
System.out.println("i. Exit.");
return (input.next());
}
public void performAction(String choice)
{
Scanner input=new Scanner(System.in);
if (choice.equalsIgnoreCase("a"))
{
BinarySearch s=new BinarySearch();
System.out.println("Enter the ID Number of the item.");
String id=input.next();
int search=search(id);
if (search==-1)
System.out.println("Item not found. Try again.");
else
{
if (items[search].getStock()==false)
System.out.println("Sorry, this item is out of stock.");
else
{
System.out.println("Please enter the renter's name in the format last,first [with no spaces].");
String name=input.next();
items[search].setName(name);
items[search].setStock(false);
System.out.println("Item checked out.");
}
}
}
else if (choice.equalsIgnoreCase("b"))
{
BinarySearch s=new BinarySearch();
System.out.println("Enter the ID Number of the item.");
String id=input.next();
int search=search(id);
if (search==-1)
System.out.println("Item not found. Try again.");
else
{
if (items[search].getStock()==true)
System.out.println("This item is already in stock.");
else
{
items[search].setName("");
items[search].setStock(true);
System.out.println("Item checked in.");
}
}
}
else if (choice.equalsIgnoreCase("c"))
{
BinarySearch s=new BinarySearch();
System.out.println("Enter the ID Number of the item.");
String id=input.next();
int search=search(id);
if (search==-1)
System.out.println("Item not found. Try again.");
else
{
if (items[search].getStock()==true)
{
System.out.println("This item is in stock.");
System.out.println(items[search]);
}
else
{
System.out.println("This item is not in stock.");
System.out.println(items[search]);
}
}
}
else if (choice.equalsIgnoreCase("d"))
{
System.out.println("Enter the title of the item [using dashes instead of spaces].");
String title=input.next();
for (int i=0; i<numItems; i++)
{
if (title.equals(items[i].title))
{
if (items[i].getStock()==true)
{
System.out.println("This item is in stock.");
System.out.println(items[i]);
}
else
{
System.out.println("This item is not in stock.");
System.out.println(items[i]);
}
}
}
}
else if (choice.equalsIgnoreCase("e"))
{
for (int i=0; i<numItems; i++)
items[i].display();
}
else if (choice.equalsIgnoreCase("f"))
{
System.out.println("Please enter an M for a movie or a G for a game.");
String type=input.next();
if (type.equalsIgnoreCase("M"))
{
System.out.println("Please enter the ID number for the movie.");
String id=input.next();
System.out.println("Please enter the movie's title (no spaces, dashes instead).");
String title=input.next();
System.out.println("Please enter the price of the movie.");
double price=input.nextDouble();
System.out.println("Please enter the run time of the movie.");
int runTime=input.nextInt();
System.out.println("Please enter the rating of the movie.");
String rating=input.next();
System.out.println("Please enter the format of the movie, V(HS) or D(VD).");
String format=input.next();
Item s=new Movie(id, title, price, true, runTime, rating, format);
addItem(s);
}
else if (type.equalsIgnoreCase("G"))
{
System.out.println("Please enter the ID number for the game.");
String id=input.next();
System.out.println("Please enter the games's title (no spaces, dashes instead).");
String title=input.next();
System.out.println("Please enter the price of the game.");
double price=input.nextDouble();
System.out.println("Please enter the age level of the game.");
int ageLevel=input.nextInt();
Item s=new Game(id, title, price, true, ageLevel);
addItem(s);
}
else
System.out.println("Invalid input. Try again.");
}
else if (choice.equalsIgnoreCase("g"))
{
System.out.println("Delete item.");
}
}
public static void main(String [] args) throws IOException
{
MovieStore m = new MovieStore("data.txt");
String choice;
do
{
System.out.println();
choice = m.menu();
m.performAction(choice);
System.out.println();
} while (!choice.equalsIgnoreCase("I")); //exits when you click i
}
}
电影和游戏类是相似的。项目实施可比较并基于ID号进行比较。它们根据项目有不同的构造函数，但它们是在MovieStore程序中正确创建的。这是文件data.txt
M 121 The-Departed 4.90 209 R D 0 Underwood,Frank
G 698 Drakes-Uncharted 3.90 0 16 White, Walter
M 345 Frozen 5.50 163 G D 0 Sheeran,Ed
M 768 School-of-Rock 1.99 155 PG V 1 empty
G 904 Lego-Batman 6.77 0 6 Pinkman,Jesse
M 564 The-Hobbit 6.50 255 PG13 D 0 Swift,Taylor
G 532 Wii-Sports 4.35 0 12 Goodman,Saul
M 196 Scarface 3.68 213 R V 1 empty
M 333 Love-Actually 4.58 130 PG13 D 1 empty
M 889 Shutter-Island 6.98 193 PG13 D 0 Smith,Matt
M 508 The-Notebook 3.45 175 PG13 V 1 empty
G 132 Fifa 8.99 0 7 Stark,Ned
G 666 Call-of-Duty 0 16 Snow,Jon
M 401 Titanic 5.90 240 PG13 V 1 empty
M 837 The-Amazing-Spiderman 6.89 198 PG D 0 Pond,Amy
M 424 The-Wolf-of-Wall-Street 9.99 216 R D 0 Lannister,Tyrion
G 999 Battlefield 7.88 1 16 empty
G 444 Borderlands 6.44 1 14 empty
M 774 Mean-Girls 3.50 154 PG13 V 1 empty
M 582 Flight 5.66 201 R D 0 Montgomery,Aria
G 999 Madden 4.33 1 10 empty
M 130 The-Boondock-Saints 6.77 234 R V 0 Beckham,David
M 420 Airplane! 6.55 121 PG V 1 empty
M 699 Inception 7.56 221 PG13 D 0 Mars,Bruno
G 100 Civilization 8.99 1 16 empty
M 834 The-Great-Gatsby 8.55 215 PG13 D 1 empty
M 555 The-Grinch 2.11 121 G V 1 empty
G 333 Pokemon 1.50 1 6 empty
M 800 21-Jump-Street 5.10 200 PG13 D 1 empty
M 945 Pitch-Perfect 7.89 191 PG13 D 0 Cyrus,Miley
这是我运行程序时遇到的错误：
java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:840)
at java.util.Scanner.next(Scanner.java:1461)
at java.util.Scanner.nextInt(Scanner.java:2091)
at java.util.Scanner.nextInt(Scanner.java:2050)
at MovieStore.<init>(MovieStore.java:51)
at MovieStore.main(MovieStore.java:233)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:272)
如果您能解释错误并让我知道我做错了什么，那就太好了！谢谢你们！
答案 0 :(得分：2)
我会在评论中添加此内容，但我还没有添加评论的声誉。
看起来问题出在输入文件上，而不一定是代码。
如果您在使用扫描仪对象时阅读了关于可能导致InputMismatchException的API，那么这将是有意义的。
输入文件的第二行在电影/游戏的租用者名称中有一个空格。 scanner.next（）调用将读取缓冲区直到该空间。这导致扫描仪拿起名称直到该空间处的点，然后名称的其余部分等待读取。一旦调用了scanner.nextInt（），你就会期望读取一个int，但是缓冲区上有一个字符串，导致InputMismatch异常。
G 698 Drakes-Uncharted 3.90 0 16 White, Walter