如何提取 .CSV 文件中的特定行？

Question

我的代码的目标是要求用户输入，用户指定这个输入，我的代码是搜索并找出用户输入所在的行。

一旦找到，我就会有代码将该行提取到某个东西（字符串数组？），这样我就可以编辑它的部分内容。

我的问题是我不确定要使用哪些代码/方法/类来执行此操作。

我现在设置了我的代码，以便它读取 .CSV 文件并将其输出到类型列表的字符串数组中。然后我遍历数组并找出指定的用户输入是否位于文件中。

目前，我的代码仅说明是否找到它，但我不确定如何提取该特定行，我希望你们能帮助我。

这是我点击按钮的代码：

try{

        String strSearch = searchSerialField.getText();

        CSVReader reader = new CSVReader(new FileReader("test.txt"), ',');
        List<String[]> myEntries = reader.readAll();
        reader.close();

        //Write to existing file
        //CSVWriter writer = new CSVWriter(new FileWriter("test.txt"), ',',CSVWriter.NO_QUOTE_CHARACTER, "\r\n");

        //Iterate through my array to find the row the user input is located on
        for (String[] line : myEntries)
        {
            ArrayList<String> newLine = new ArrayList<String>();
            for (String word : line)
            {
                if (word.contains(strSearch))
                {
                    //Need a method so I can find out what row my item is on
                    System.out.println("Found - Your item is on row: ...");

                    //Code to extract row into something (String array?) so I can edit it's contents

                    //I then need to write the edited row back to it's original row

                }else
                {
                    System.out.println("Not found");
                }
            }
        }

   }catch (IOException e)
        {
            System.out.println(e);
        }

我已经尽了最大努力，但我现在对如何提取行感到困惑，我该怎么做呢？

感谢您的帮助。

Answer 1

您需要的不是嵌套循环，而是一个 Arrays.toString 方法。

import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

import com.opencsv.CSVReader;


public class Test {
    public static void main(String[] arg){
        search();
    }
    public static void search(){
        try{

            String strSearch = "banana";

            CSVReader reader = new CSVReader(new FileReader("d:\\textfile.txt"), ',');
            List<String[]> myEntries = reader.readAll();
            System.out.println(myEntries.size());
            reader.close();

            //Write to existing file
            //CSVWriter writer = new CSVWriter(new FileWriter("test.txt"), ',',CSVWriter.NO_QUOTE_CHARACTER, "\r\n");

            //Iterate through my array to find the row the user input is located on
            int i=1;
            for (String[] line : myEntries)
            {

                String textLine = Arrays.toString(line).replaceAll("\\[|\\]","");
                System.out.println(textLine);
                  if (textLine.contains(strSearch))
                    {
                        //Need a method so I can find out what row my item is on
                        System.out.println("Found - Your item is on row: ...:"+i);

                        //Code to extract row into something (String array?) so I can edit it's contents

                        //I then need to write the edited row back to it's original row

                    }else
                    {
                        System.out.println("Not found");
                    }
                  i++;
            }

       }catch (IOException e)
            {
                System.out.println(e);
            }
    }
}

Answer 2

您可以通过简单地计算索引来实现。

    String strSearch = searchSerialField.getText();
    CSVReader reader = new CSVReader(new FileReader("test.txt"), ',');
    List<String[]> myEntries = reader.readAll();
    reader.close();

    for (int row = 0; row<myEntries.size(); row++){
        for (int column = 0; column< myEntries.get(row).length; column++ ){
            if(myEntries.get(row)[column].trim().equalsIgnoreCase(strSearch)){
                System.out.println("found - your item is on row " +row + ", column "+ column);
            }              
        }
    }

Answer 3

public static String[] getSpecificRowFromCsv(String filePath, int rowNum) {
    List<String[]> fileData = null;
    CSVReader reader = null;
    try {
        reader = new CSVReader(new FileReader(filePath));
        fileData = reader.readAll();
        reader.close();
    } catch (Exception e) {
        e.printStackTrace();
    }             

    return fileData.get(rowNum - 1);
}