Question

我有一个csv文件，如下所示：

ID，价格，描述，长度，高度，类别

每个后续列都填入相关数据。我有一个读取器类，它读取这些数据并将其显示在一个单独的演示类中（通过实例化它）。这就是我在以下方面阅读csv文件的方法：

 public CatalogueReader(String filename) throws FileNotFoundException {
    this.filename = filename;
    this.catalogue = new Catalogue();

    Scanner csvFile;
    try {
        csvFile = new Scanner(new File(filename));
    } catch (FileNotFoundException fnf) {
        throw new FileNotFoundException("File has not been found!!!! Probably in wrong place!");
    }
    csvFile.useDelimiter("\n");
    boolean first = true;
    String productCode;
    double price;
    String description;
    double weight;
    int rating;
    String category;
    boolean ageRestriction;
    String rows;
    while (csvFile.hasNextLine()) {
        rows = csvFile.nextLine();
        if (first) {
            first = false;
            continue;
        }
        System.out.println(rows);
        String[] fields = rows.split(",");
        productCode = (fields[0].trim());
        price = Double.parseDouble(fields[1].trim());
        description = fields[2].trim();
        weight = Double.parseDouble(fields[3].trim());
        rating = Integer.parseInt(fields[4].trim());
        category = fields[5].trim();
        ageRestriction = Boolean.parseBoolean(fields[6].trim());
        catalogue.addAProduct(new Item(productCode, price, description, weight, rating, category, ageRestriction));
        //System.out.println("PC is " + productCode);
    }
    csvFile.close();
}

我的问题是，是否有基于特定ID打印特定行的方法？

非常感谢任何指导。

Answer 1

您可以通过row.contains（searchID）进行检查。您只能在searchID匹配时进行解析。我刚刚添加 if（！rows.contains（productCode））继续; 进行此检查

  while (csvFile.hasNextLine()) {
        rows = csvFile.nextLine();

        if (first) {
            first = false;
            continue;
        }

        if(!rows.contains(productCode)) continue;

        System.out.println(rows);
        String[] fields = rows.split(",");
        productCode = (fields[0].trim());
        price = Double.parseDouble(fields[1].trim());
        description = fields[2].trim();
        weight = Double.parseDouble(fields[3].trim());
        rating = Integer.parseInt(fields[4].trim());
        category = fields[5].trim();
        ageRestriction = Boolean.parseBoolean(fields[6].trim());
        catalogue.addAProduct(new Item(productCode, price, description, weight, rating, category, ageRestriction));
        //System.out.println("PC is " + productCode);
    }

Answer 2

通过传递方法中的值，您可以逐行检查该值，如果该行已找到中断循环。

public void CatalogueReader(String filename,String id) throws IOException{
            BufferedReader br = null;
            String line = "";
            String cvsSplitBy = ",";

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

                    // use comma as separator
                String[] lineArray = line.split(cvsSplitBy);
                //Check the value from array
                //if(lineArray[xxx]==id){
                //Print the line
                          break;
                }



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

            }

从csv文件打印特定行

2 个答案: