如何将两个ArrayLists打印到具有多列的csv文件中? [英] How to print two ArrayLists to a csv file with multiple columns?

问题描述

我有两个数组列表，如下所示，

I have two array lists like shown below,

import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.*;

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

        ArrayList<String> animal = new ArrayList<>();
        animal.add("Dog");
        animal.add("Cat");
        animal.add("Mouse");

        ArrayList<Integer> numbers = new ArrayList<>();
        for (int i = 1; i <= 15; i++) {
            numbers.add(i);
        }

        PrintWriter writer = new PrintWriter("animals.csv");

        for (String ani : animal) {
            writer.println(ani + ",");
        }

        writer.close();    
    }
}

我希望.csv文件中的输出像这样.

I want the output to be like this in the .csv file.

Dog,1,2,3,4,5,
Cat,6,7,8,9,10,
Mouse,11,12,13,14,15,

当我使用for循环时，在.csv文件中，数组列表的输出将一个显示在另一个下方.

When I use for-loops, the output of the array lists gets printed one below the other in the .csv file.

如何格式化所需的数组列表，使其在Excel中看起来像这样?

How do I format the array lists the way I desired, so it looks like this in Excel?

推荐答案

使用writer.print()代替writer.println()

在您使用的方法名称中注意'ln'，表示打印行.

Notice 'ln' in the method name you are using, which means print line.

更新:要同时添加数字和动物:

Update: To also add numbers along with animal:

public static void main(final String[] args) throws FileNotFoundException {
    ArrayList<String> animal = new ArrayList<>();
    animal.add("Dog");
    animal.add("Cat");
    animal.add("Mouse");

    ArrayList<Integer> numbers = new ArrayList<>();
    for (int i = 1; i <= 15; i++) {
        numbers.add(i);
    }

    PrintWriter writer = new PrintWriter("animals.csv");

    List<String> row = new ArrayList<>();
    int i = 0;
    for (String ani : animal) {
        row.add(ani);
        for (int j = 0; j < 5; j++) {
            row.add(String.valueOf(numbers.get(i++)));
        }
        writer.println(String.join(",", row));
        row.clear();
    }

    writer.close();
}

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