java从csv文件中读取并将其信息存储到ArrayList<class>中

java reading from csv file and storing its information into ArrayList<class>

提问by cohsta

I'm a java newbie and I need a some help

我是一个 Java 新手，我需要一些帮助

so here is my main method:

所以这是我的主要方法：

RegistrationMethods dmv = new RegistrationMethods();
ArrayList<CarOwner> ItState = new ArrayList<CarOwner>();
dmv.processTextToArrayList(ItState);

and I have a class called CarOwnerand it has getters and setters for firstName, lastName, license, month, yearinstance variables.

我有一个名为的类CarOwner，它具有用于firstName, lastName, license, month, year实例变量的getter 和 setter 。

And this is my method header for processTextToArrayListmethod:

这是我的方法标题processTextToArrayList：

public void processTextToArrayList(ArrayList<CarOwner> inList) throws IOException

this method is supposed to add new CarOwnerobjects to the inList CarOwnercollection passed in. For each line of the csv file, a CarOwnerobject is added to inList.

此方法应该向传入CarOwner的inList CarOwner集合添加新对象。对于 csv 文件的每一行，将一个CarOwner对象添加到inList.

I have to read from csv file into arraylist my csv file contains something like:

我必须从 csv 文件读取到 arraylist 我的 csv 文件包含如下内容：

Bunny Bugs ACB-123 5 2013

Bunny Honey DEF-456 9 2013

Bunny Lola GHI-789 3 2014

how do I code this using while loop?

我如何使用while循环对此进行编码？

edit:

编辑：

my CarOwner class is :

我的 CarOwner 课程是：

public class CarOwner extends Citizen implements CarOwnerInterface, Serializable
{
private String license;
private int month, year;

public CarOwner()
{
    super();
    license = "Not Assigned";
    month = 0;
    year = 0;        
}

public CarOwner(String inFirst, String inLast, String inLicense, int inMonth, int inYear)
{
    super(inFirst, inLast);
    license = inLicense;
    month = inMonth;
    year = inYear;
}

public void setLicense(String inLicense)
{
    license = inLicense;
}

public String getLicense()
{
    return license;
}

public void setMonth(int inMonth)
{
    month = inMonth;
}

public int getMonth()
{
    return month;
}

public void setYear(int inYear)
{
    year = inYear;
}

public int getYear()
{
    return year;
}

public int compareTo(Object o)
{
    if ((o != null ) && (o instanceof CarOwner))
    {
        CarOwner otherOwner = (CarOwner) o;
        if (otherOwner.compareTo(getYear()) > 0)
            return -1;
        else if (otherOwner.compareTo(getYear()) < 0)
            return 1;
        else if (otherOwner.equals(getYear()))
            if (otherOwner.compareTo(getMonth()) > 0)
                return -1;
            else if (otherOwner.compareTo(getMonth()) < 0)
                return 1;
            else if (otherOwner.equals(getMonth()))
                return 0;
    }
    return -1;
}

}

}

and my Citizen class is also:

我的公民课也是：

public class Citizen implements CitizenInterface, Serializable
{
private String firstName, lastName;

public Citizen()
{
    firstName = "No Name";
    lastName = "No Name";
}

public Citizen(String inFirstName, String inLastName)
{
    firstName = inFirstName;
    lastName = inLastName;
}

public void setFirstName(String inFirst)
{
    firstName = inFirst;
}

public String getFirstName()
{
    return firstName;
}

public void setLastName(String inLast)
{
    lastName = inLast;
}

public String getLastName()
{
    return lastName;
}

public String toString()
{
    String str;

    str = firstName + " " + lastName;

    return str;
}

回答by austin wernli

You could use a method like this and provide the path to the file you wish to read from. This creates a Scanner to read from the file passed in.

您可以使用这样的方法并提供要读取的文件的路径。这将创建一个扫描器来读取传入的文件。

It grabs each line one at a time and adds a new CarOwner(String,String,String,String,String) object to the result array.

它一次抓取每一行，并将一个新的 CarOwner(String,String,String,String,String) 对象添加到结果数组中。

P.S. i have no idea your implementation of CarOwner so i just used all Strings... I'll leave that to you to figure out heh.

PS 我不知道你对 CarOwner 的实现，所以我只使用了所有的字符串......我会把它留给你来弄清楚。

public ArrayList < CarOwner > processTextToCarOwnerList(String filePath) throws IOException {
    ArrayList < CarOwner > result = new ArrayList < CarOwner > ();
    Scanner scan = new Scanner(new File(filePath));
    while (scan.hasNextLine()) {
        String line = scan.nextLine();
        String[] lineArray = line.split(" ");
        result.add(new CarOwner(lineArray[0], lineArray[1], lineArray[2], lineArray[3], lineArray[4]));
        }
        return result;
    }

回答by Phiwa

You could use something like this:

你可以使用这样的东西：

ArrayList<CarOwner> owners = new ArrayList<CarOwner>();

BufferedReader br = new BufferedReader(new FileReader(new File("path/to/your/file.csv")));
String line;
while ((line = br.readLine()) != null) {

    String[] entries = line.split(",");

    CarOwner owner = new CarOwner(entires[0], entries[1], entries[2], entries[3]);

    owners.add(owner);
}

Do you have a real csv file (all values separated by ,) or are they separated by spaces or something like that? In that case you'd have to replace the , with spaces.

你有一个真正的 csv 文件（所有值都用 , 分隔）还是用空格或类似的东西分隔？在这种情况下，您必须将 , 替换为空格。