Question

I also wrote that article. That article is about large files, and this question does not assume that the files are large. And there is no concrete solution.

i have 39 csv files . I want to load this file by Java and set as one variable. Below paragraph is my coding which works for one file, but i don't know how to multiple file merge. I want to load 39 file in directory and put them into one 2d array.

public static String readCSV(File csvFile) {
    BufferedReader bufferedReader = null;
    StringBuffer stringBuffer = new StringBuffer();

    try {
        bufferedReader = new BufferedReader(new FileReader(csvFile));
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

    try {
        String temp = null;
        while((temp = bufferedReader.readLine()) != null) {
            stringBuffer.append(temp+","); // temp 에 저장되어있는 한 줄을 더한다.
        }

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

    // -10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,,,,,,,,,,1,2,3,4,5,6,7,8,9,10, 반환
    return stringBuffer.toString();
}

public static String[] parse(String str) {
    String[] strArr = str.split(","); // 쉼표가 1개인 것을 기준으로 나누어서 배열에 저장

    return strArr; 
}

public static void main(String[] args) throws IOException {

    //mergeCsvFiles("sample", 4, "D:\\sample_folder\\" + "merge_file" + ".csv");


    String str = readCSV(new File("D:/sample_folder/sample1.csv"));
    String[] strArr = parse(str); // String 배열에 차곡차곡 담겨서 나온다.
    int varNumber = 45;
    int rowNumber = strArr.length/varNumber;

    String[][] Array2D = new String[varNumber][rowNumber];
    for(int j=0;j<varNumber;j++)
    {
        for(int i=0; i<rowNumber;i++)   
            {
                String k = strArr[i*varNumber+j];
                        Array2D[j][i]= k;
        }
    }                       //2D array 배열을 만들기      

    //String[][] naArray2D=removeNA(Array2D,rowNumber,varNumber); //NA 포함한 행 지우기





//      /*  제대로 제거 됐는지 확인하는 코드
    for(int i=0;i<varNumber;i++){
        for(int j=0;j<16;j++){
                            System.out.println(Array2D[i][j]);
        }
                        System.out.println("**********************NA제거&2차원 배열**********************");
    }           
//      */

    }
}

Answer 1

您的逻辑是正确的，对于多个文件，您可以将所有这些csv文件放在一个目录中，并使用java列表文件，您可以通过以下方式获取所有文件名

 File txtPat = new File("C:\\Users\\Admin\\Desktop\\") ;
 File allFile[] = txtPat.listFiles();

 for(int i = 0 ;i<allFile.length;i++)
 {
    System.out.println(allFile[i]);
 }

how to merge 39 csv file and put them a 2D array

1 个答案: