从CSV文件自动创建数组时，索引1超出了长度1错误的范围 [英] Index 1 out of bounds for length 1 error while creating the array automatically from the CSV file

问题描述

这个问题看似微不足道，但我仍在努力。错误是 java.lang.ArrayIndexOutOfBoundsException：索引1的长度为1 ，据我了解，只能访问数组中的第一个索引（ id （在这种情况下是主键）。这是为什么？加载文件CSV文件时，我是否不根据定界符分隔的项目数自动确定数组的长度？然后我的 readFile（）方法怎么了？

The problem seems to be trivial but I still struggle on it. The error is java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1 from which I understand only the first index from the array can be accessed (id which is the primary key in that case). Why is that? Don't I determine the length of the array automatically based on the number of items separated by delimiter when I load the file CSV file ? What is wrong with my readFile() method then ?

import javax.persistence.*;

@Table
@Entity(name="users")

public class UserData {



    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column
    private String firstName;

    @Column
    private String lastName;

    @Column
    private int telephoneNo;

    @Column
    private String email;

    @Column
    private String pickUp;

    @Column
    private String dropOff;

    public UserData(){}


    public UserData(String firstName, String lastName, int telephoneNo, String email, String pickUp, String dropOff){
        this.firstName = firstName;
        this.lastName = lastName;
        this.telephoneNo = telephoneNo;
        this.email = email;
        this.pickUp = pickUp;
        this.dropOff = dropOff;
    }



    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public int getTelephoneNo() {
        return telephoneNo;
    }

    public void setTelephoneNo(int telephoneNo) {
        this.telephoneNo = telephoneNo;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPickUp() {
        return pickUp;
    }

    public void setPickUp(String pickUp) {
        this.pickUp = pickUp;
    }

    public String getDropOff() {
        return dropOff;
    }

    public void setDropOff(String dropOff) {
        this.dropOff = dropOff;
    }
}

sample.csv

sample.csv

1,Reanna,Colepio,159031625,[e-mail],London,Glasgow
2,Rita,Das,987443767,[e-mail],Edinburgh,Glasgow

ManageData.java

ManageData.java

import org.hibernate.Session;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

import java.util.Scanner;

public class ManageData {

    public static void readFile() {
        String line = "";

        Session session = HibernateConfig.getSessionFactory().openSession();

        try (BufferedReader br = new BufferedReader(new FileReader("/Users/ggabrychowicz/IdeaProjects/Bus Managing System/src/main/java/sample.csv"))){

            while ((line = br.readLine()) != null){
                String[] tempArr = line.split(",");

                UserData userData = new UserData();


                userData.setFirstName(tempArr[1]);
                userData.setLastName(tempArr[2]);
                userData.setTelephoneNo(Integer.parseInt(tempArr[3]));
                userData.setEmail(tempArr[4]);
                userData.setPickUp(tempArr[5]);
                userData.setDropOff(tempArr[6]);

                session.beginTransaction();
                session.save(userData);
                session.getTransaction().commit();

            }
            session.close();
        }

        catch (IOException e) {
            if (session!=null){
                session.getTransaction().rollback();
            }
            e.printStackTrace();
        }
    }
}

这就是我的意思当我打印数组时得到：

1
Reanna
Colepio
159031625
[e-mail]
London
Glasgow
2
Rita
Das
987443767
[e-mail]
Edinburgh
Glasgow
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
    at ManageData.readFile(ManageData.java:26)
    at Main.main(Main.java:4)

推荐答案

我对csv和room不太了解，但是我读过某处的标头也算作一行

I don't know much about csv and room , but i read somewhere the header is also counted as a row

所以

我认为当您说 line = br.readLine（）时，它会读取csv文件的头文件进行第一次迭代，并且该头文件没有任何逗号，因此 line.split 仅返回ome字符串，当您说 temArr [1] 时，这是错误的因为数组中只有一个字符串，并且索引为零。

i think when you say line = br.readLine() it read the header of the csv file for the first iteration, and that header does not have any comma so line.split only returns ome string , and when you say temArr[1] it is wrong because there is only one string in the array and it is at zero index.

您应该尝试打印该数组，否则您会知道天气是否正确，请还请让我知道，因为我不确定，这只是个主意。

You should try printing that array then you will know weather or not i am right, and please also let me know, cuz it is just an idea, i am not sure.

如果事实是这样，您可以 br.readline 进入while循环之前，它将按预期运行

And if that turns out to be the case you can you br.readline before entering the while loop and it will work an you expected

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