java.util.NoSuchElementException 在主要方法中使用带输入和输出文本文件的扫描仪

Question

错误：

    Exception in thread "main" java.util.NoSuchElementException: No line found
at java.util.Scanner.nextLine(Unknown Source)
at PetOrganizer.main(PetOrganizer.java:23)

这是与宠物 Class 交互的主要 class，也发布在下面。第一次使用 FileWriter，所以如果我在这里做错了什么，请告诉我。我的主要 class 代码的第 23 行与 "String name".

类似

编辑：添加了 input.txt 文件，还有一个 output.txt 文件，程序打算打印到该文件，但它是空的

代码：

    import java.util.Scanner;
    import java.io.*;

    public class PetOrganizer {

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

    //Intialize Text File along with Writer variables
    File TextFile = new File("input.txt");
    File OutputFile = new File("output.txt");
    FileWriter fWriter = new FileWriter(TextFile, true);
    FileWriter fOWriter = new FileWriter(OutputFile);
    PrintWriter pWriter = new PrintWriter(fOWriter);


    //Initialize Scanner Variable
    Scanner in = new Scanner(TextFile);


    //Gets input from user for pet #1
    System.out.println("Please enter what you would like your first pet to be named: ");

这在代码中被删减是为了显示导致上述错误的第 23 行

    String name =  in.nextLine();

    System.out.println("Please enter how old you would like "+name+" to be:");
    int age = in.nextInt();

    System.out.println("Please enter what type of pet you would like(Dog, Cat, Mouse, Ferret): ");
    String pettype = in.nextLine();

    System.out.println("Please enter the name of "+name+"'s owner");
    String owner = in.nextLine();

    //Creates first instance of Pet and uses input from user
    Pet p1 = new Pet();
    p1.setPetAge(age);
    p1.setPetName(name);
    p1.setPetType(pettype);
    p1.setPetOwner(owner);

    //Gets input from user for pet #1
    System.out.println("Please enter what you would like your second pet to be named: ");
    name = in.nextLine();

    System.out.println("Please enter how old you would like "+name+" to be:");
    age = in.nextInt();

    System.out.println("Please enter what type of pet you would like(Dog, Cat, Mouse, Ferret): ");
    pettype = in.nextLine();

    System.out.println("Please enter the name of "+name+"'s owner");
    owner = in.nextLine();

    //Creates first instance of Pet and uses input from user
    Pet p2 = new Pet();
    p2.setPetAge(age);
    p2.setPetName(name);
    p2.setPetType(pettype);
    p2.setPetOwner(owner);      

    //Gets input from user for pet #1
    System.out.println("Please enter what you would like your third pet to be named: ");
    name = in.nextLine();

    System.out.println("Please enter how old you would like "+name+" to be:");
    age = in.nextInt();

    System.out.println("Please enter what type of pet you would like(Dog, Cat, Mouse, Ferret): ");
    pettype = in.nextLine();

    System.out.println("Please enter the name of "+name+"'s owner");
    owner = in.nextLine();

    //Creates first instance of Pet and uses input from user
    Pet p3 = new Pet();
    p3.setPetAge(age);
    p3.setPetName(name);
    p3.setPetType(pettype);
    p3.setPetOwner(owner);      

    //Outputs all of the instances of Pet with the info gathered from user input
    pWriter.println("/////////////////////////////////////////////////////////");
    pWriter.println("///////////////////PATIENT LIST//////////////////////////");
    pWriter.println("Pet 1");
    pWriter.println("Pet 1 Age: "+ p1.getPetAge());
    pWriter.println("Pet 1 Name: "+p1.getPetName());
    pWriter.println("Pet 1 Type: "+p1.getPetType());
    pWriter.println("Pet 1 Owner: "+p1.getPetOwner());
    pWriter.println("Pet 2");
    pWriter.println("Pet 2 Age: "+ p2.getPetAge());
    pWriter.println("Pet 2 Name: "+p2.getPetName());
    pWriter.println("Pet 2 Type: "+p2.getPetType());
    pWriter.println("Pet 2 Owner: "+p2.getPetOwner());
    pWriter.println("Pet 3");
    pWriter.println("Pet 3 Age: "+ p3.getPetAge());
    pWriter.println("Pet 3 Name: "+p3.getPetName());
    pWriter.println("Pet 3 Type: "+p3.getPetType());
    pWriter.println("Pet 3 Owner: "+p3.getPetOwner());
    pWriter.println("//////////////////////////////////////////////////////////");
    pWriter.println("//////////////////////////////////////////////////////////");

    fWriter.close();
    pWriter.close();
    in.close();

}

}

宠物Class代码：

    public class Pet {
//Class Private Data Members
private String petName;
private int petAge;
private String petType; //Cat, Dog, Ferret, etc
private String petOwner;

//Constructor
public Pet()
{

}

//Public Methods
public String getPetName() {
    return petName;
}

public void setPetName(String name) {
    petName = name;
}

public int getPetAge() {
    return petAge;
}

public void setPetAge(int age) {
    petAge = age;
}

public String getPetType() {
    return petType;
}

public void setPetType(String type) {
    petType = type;
}

public String getPetOwner() {
    return petOwner;
}

public void setPetOwner(String owner) {
    petOwner = owner;
}

}

输入文件：

    George
    18
    Dog
    Ben
    Fred
    19
    Ferret
    Carl
    Steve
    20
    Cat
    Dog

Answer 1

如果您需要使用文件，您可以使用 bufferedReader 逐行浏览文本文件，直到完成。例如，如果您有一个文本文件

Dog1

Dog2

第一次通过 while 循环时，字符串 currentWord 是“Dog1” 第二次通过 while 循环时，字符串 currentWord 是“Dog2” 等等

public static void main(String[] args) 
    {
    try (BufferedReader br = new BufferedReader(new FileReader("C:\words.txt")))
        {
            String currentWord;
            while ((currentWord = br.readLine()) != null)
            {
               //USE EACH OF YOUR STRINGS HERE i.e String dogName = currentWord
            }
        } 
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }

“C:\words.txt”指的是您要使用的文件所在的位置。使用这个只需导入

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.*;

java.util.NoSuchElementException 在主要方法中使用带输入和输出文本文件的扫描仪

java.util.NoSuchElementException in main method using Scanner w/ input & output text files

java

java.util.scanner

nosuchelementexception