Question

这是我的代码

package sequentialFilePractice;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;

public class ReadFile{

static String line = "";

ReadFile() throws FileNotFoundException{
    readTheFile();
    CSVtoArrayList();
}

public String readTheFile() throws FileNotFoundException{
    String csvFile = "H:\\S6\\AH Computing\\Java Practice\\test.csv";
    BufferedReader br = null;
    String cvsSplitBy = ",";

    try {

        br = new BufferedReader(new FileReader(csvFile));
        while ((line = br.readLine()) != null) {


        }

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (br != null) {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return line;


}

public static ArrayList<String> CSVtoArrayList() {
    ArrayList<String> splitCSV = new ArrayList<>();

    if (line != null) {
        String[] splitData = line.split("\\s*,\\s*");
        for (int i = 0; i < splitData.length; i++) {
            if (!(splitData[i] == null) || !(splitData[i].length() == 0)) {
                splitCSV.add(splitData[i].trim());
            }
        }
    }

    for(int j = 0;j < splitCSV.size();j++){
        System.out.println(splitCSV.get(j));
    }
        return splitCSV;
    }

public static void main(String[]args) throws IOException{
    ReadFile f = new ReadFile();
}
}

代码编译，文件存在。我可以打印行并打印文件的内容但是当我打印arrayList时，没有输出任何内容，所以它没有被复制。这是我第一次在java中使用顺序文件。

Answer 1

您是否必须手动阅读该文件？如果没有，您应该查看http://opencsv.sourceforge.net/，它允许您直接将CSV读取到List<String[]>，而不必处理循环管理，拆分行并创建列表。

实质上将代码缩减为：

CSVReader reader = new CSVReader(new FileReader("yourfile.csv"));
List myEntries = reader.readAll();

如何将CSV文件打印到ArrayList？

1 个答案: