java - 使用扫描仪读取文件时线程 "main"java.util.InputMismatchException 中出现异常

Question

我正在尝试从文本文档中读取数据，格式如下:

123 Fluffy      12/04/2017  34  2   
124 Domino      11/23/2018  12  1
125 Rover       9/8/2018    45  10

它应该输出如下:

ID No. 123 : Fluffy : 2 years old : 34lbs 
Registered on 12/04/2017
ID No. 124 : Domino : 1 years old : 12lbs 
Registered on 11/23/2018
ID No. 125 : Rover : 10 years old : 45lbs 
Registered on 9/8/2018

但是，执行此操作时，它会输出以下错误:

Exception in thread "main" java.util.InputMismatchException
    at java.base/java.util.Scanner.throwFor(Scanner.java:939)
    at java.base/java.util.Scanner.next(Scanner.java:1594)
    at java.base/java.util.Scanner.nextInt(Scanner.java:2258)
    at java.base/java.util.Scanner.nextInt(Scanner.java:2212)
    at DogRunner1.main(DogRunner1.java:56)

该对象的代码如下所示:

public class Dog1
{

String name;

int age;
// regDate -- registration date (in the format: "YYYY/MM/DD")
String regDate;
int weight;
int idNumber;


public String bark() {
    return "bark";
}

public  void setAge(int a) {
    age = a;
}

public void setRegDate(String b) {
    regDate = b;
}
public void setId(int c) {
    idNumber = c;
}
public void setWeight(int d) {
    weight = d;
}

public String toString()
   {
       return "ID No. " + idNumber + " : " + name + " : " + age + " years old : " + weight +"lbs \nRegistered on " + regDate;
   }
}

运行它的程序的代码如下所示:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class DogRunner1
{


   public static void main(String[] args) throws FileNotFoundException
   {


    Dog1 d3;
    d3 = new Dog1();

    File text = new File ("dogdata.txt");
    Scanner inFile = new Scanner(text);
    while(inFile.hasNext()) {
        d3.setId(inFile.nextInt());
        d3.name = inFile.nextLine();
        inFile.nextLine();
        d3.setRegDate(inFile.nextLine());
        d3.setWeight(inFile.nextInt());
        d3.setAge(inFile.nextInt());
        System.out.println(d3);
        inFile.nextLine();
    }
        inFile.close();
   }
}

我知道你必须在两个字符串之间跳过一行，或者至少我认为这就是我的想法，并且我尝试了许多 nextLine() 放置的组合，但无济于事。我不知道出了什么问题，请帮忙。

Answer 1

您正在使用 nextLine() 读取名称和 regDate 字段。该方法读取该行的其余部分。您不希望这样，您只想读取单个单词，因此您应该使用 next():

    d3.setId(inFile.nextInt());
    d3.name = inFile.next();
    d3.setRegDate(inFile.next());
    d3.setWeight(inFile.nextInt());
    d3.setAge(inFile.nextInt());
    System.out.println(d3);