Question

所以我昨天运行了这个程序，不小心在netbeans IDE 7.4中运行了调试器控制台，自从程序停止工作以来。我不知道我的代码中发生了什么变化。

这是错误：

Petname: 
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at veterinarian.Veterinarian.main(Veterinarian.java:107)
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)

我添加了一个简单的println语句来查看存储的内容及其null是否为petname。

代码是：

public static void main(String[] args) {
    boolean pick = false;       
//***************************add file*******************************************
File file = new File("VetList.txt");      
//*********************declare ojbects******************************************
try{
        Scanner read = new Scanner(file);
        int fix = read.nextInt();
        do{
        for(int x = 0; x < fix; x++){
            String petname = read.nextLine();
            System.out.println("Petname: " + petname);
            int birthday = read.nextInt();
            String species = read.next();
            double bill = read.nextDouble();
            String owner = read.next();
            Veterinarian work = new Veterinarian(petname, birthday, species, bill, owner);
            Veterinarian.Vet.add(work);
            }
    }
    while(read.hasNextLine() == pick);
    }  
catch(FileNotFoundException FNF){
    System.err.format("File not found");}

txt文件是：

8
hopper
2003
kangaroo
555
Melody_harper
ketty
2009
cat
44
Kitty_katz
Spot
2005
Dog
333
Dottie_Marks
Johnny
2008
cat
111
Misty_waters
Stripper
2011
sckunk
432 
Oddie_sweet
Edward
1995
Horse
630
Frieda_gelding
Casper
1998
snake
88
Bo_constricter
boots
2005
Horse
987
Ida_Shuman

我无法更改文件格式以便更好地阅读。

请注意，我已经尝试将java文件本身恢复到此事件之前的时间，但它仍然无法运行并产生相同的错误。我也重新安装了Netbeans。

Answer 1

如果您将所有数据类型更改为String并将代码更改为此类

，则进行调试

                String petname = read.nextLine();
                System.out.println("Petname: " + petname);

                String birthday = read.next();
                String species = read.next();
                String bill = read.next();
                String owner = read.next();
                System.out.println("BirthDay" + birthday);
                System.out.println("Name"+petname);
                System.out.println("BIll" + bill);
                System.out.println("Speci" + species);
                System.out.println("Owner " + owner);

你应该得到像

这样的输出

 Petname: 
 BirthDayhopper
 Name
 BIllkangaroo
 Speci2003
 Owner 555

这意味着你的生日是一个字符串，但你试图存储为int ..这就是为什么它给出了例外。如果您将代码更改为以下

 if (read.hasNext()) {
  //if prevents NoSuchElementException
                    String petname = read.next();
                    System.out.println("Petname: " + petname);

                    int birthday = read.nextInt();
                    String species = read.next();
                    double bill = read.nextDouble();
                    String owner = read.next();
                    System.out.println("BirthDay" + birthday);
                    System.out.println("Name" + petname);
                    System.out.println("BIll" + bill);
                    System.out.println("Speci" + species);
                    System.out.println("Owner " + owner);
                }

您可以获得所需的输出和所需的数据类型。

输入不匹配扫描仪出现异常错误

1 个答案: