未指定标头映射，无法按名称访问记录值（Apache Commons CSV）

csv java apache-commons apache-commons-csv

2022-08-31 17:15:51

当我尝试读取csv时，我收到此错误消息：

Exception in thread "main" java.lang.IllegalStateException: No header mapping was specified, the record values can't be accessed by name
at org.apache.commons.csv.CSVRecord.get(CSVRecord.java:99)
at mockdata.MockData.main(MockData.java:33)

Java 结果： 1

我正在使用Apache Commons CSV库1.1。尝试谷歌搜索错误消息，我得到的唯一一件事是像grepcode这样的网站上的代码列表。

这是我的代码：

package mockdata;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVRecord;

public class MockData
{

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws FileNotFoundException, IOException
    {
        Reader in = new InputStreamReader(MockData.class.getClassLoader()
                                .getResourceAsStream("MOCK_DATA.csv"), "UTF-8");
        Iterable<CSVRecord> records = CSVFormat.EXCEL.parse(in);
        for (CSVRecord record : records) 
        {
            String lastName = record.get("last_name");
            String firstName = record.get("first_name");

            System.out.println("firstName: " + firstName + " lastName: " + lastName);
        }
    }

}

CSV 的内容：

first_name,last_name,address1,city,state,zip,country,phone,email
Robin,Lee,668 Kinsman Road,Hagerstown,TX,94913,United States,5-(078)623-0713,rlee0@e-recht24.de
Bobby,Moreno,68 Dorton Avenue,Reno,AZ,79934,United States,5-(080)410-6743,bmoreno1@ihg.com
Eugene,Alexander,3 Bunker Hill Court,Newark,MS,30066,United States,5-(822)147-6867,ealexander2@gmpg.org
Katherine,Crawford,3557 Caliangt Avenue,New Orleans,OR,23289,United States,2-(686)178-7222,kcrawford3@symantec.com

它位于我的 src 文件夹中。

答案 1

使用Header（）调用默认的Excel CSV格式对我有用：

CSVFormat.EXCEL.withHeader().parse(in);

文档中的示例不是很清楚，但您可以在此处找到它：安全地引用列：如果您的源代码包含标题记录，则可以通过使用没有参数的withHeader（String...）来简化代码并安全地引用列：CSVFormat.EXCEL.withHeader（）;

答案 2

这对我有用

try (Reader in = new FileReader(f);
                CSVParser parser = new CSVParser(in,
                        CSVFormat.EXCEL.withDelimiter(';').withHeader("Assembly Item Number", "Material Type",                              "Item Name", "Drawing Num", "Document Type", "Revision", "Status", "Drawing name",
                                "BOM Material Type", "Component Name"));) {
            for (CSVRecord record : parser) {
                    System.out.println(record.get("Item Name"));
            }
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }