Question

我有这个.csv输入文件（这里只是一个示例-有1.500.000行）

OBJECT_ID¦TYPE¦NAME¦PARENT_ID¦MANUFACTURER¦POSITION_CODE¦MAINTENANCE_STATUS¦PHYSICAL_STATUS
9143101068113202824¦Card¦H603CSRI - 6¦9143101069013360101¦Huawei Technologies¦74EX.G010.R13.031 (H603).006¦Not on Maintenance¦In Service
9143101068113202825¦Card¦H603CSRI - 7¦9143101069013360101¦Huawei Technologies¦74EX.G010.R13.031 (H603).007¦Not on Maintenance¦In Service

我创建了一个名为Card的模型类

public class Card {
    @CsvBindByName(column = "OBJECT_ID")
    private String object_id;

    @CsvBindByName(column = "TYPE")
    private String type;

    @CsvBindByName(column = "NAME")
    private String name;

    @CsvBindByName(column = "PARENT_ID")
    private String parent_id;

    @CsvBindByName(column = "MANUFACTURER")
    private String manufacturer;

    @CsvBindByName(column = "POSITION_CODE")
    private String position_code;

    @CsvBindByName(column = "MAINTENANCE_STATUS")
    private String maintenance_status;

    @CsvBindByName(column = "PHYSICAL_STATUS")
    private String physical_status;

public Card() { }
public Card(String object_id, String type, String name, String parent_id, String manufacturer, String position_code, String maintenance_status, String physical_status) {
    this.object_id = object_id;
    this.type = type;
    this.name = name;
    this.parent_id = parent_id;
    this.manufacturer = manufacturer;
    this.position_code = position_code;
    this.maintenance_status = maintenance_status;
    this.physical_status = physical_status;
}

public String getObject_id() {
    return object_id;
}

public void setObject_id(String object_id) {
    this.object_id = object_id;
}

public String getType() {
    return type;
}

public void setType(String type) {
    this.type = type;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getParent_id() {
    return parent_id;
}

public void setParent_id(String parent_id) {
    this.parent_id = parent_id;
}

public String getManufacturer() {
    return manufacturer;
}

public void setManufacturer(String manufacturer) {
    this.manufacturer = manufacturer;
}

public String getPosition_code() {
    return position_code;
}

public void setPosition_code(String position_code) {
    this.position_code = position_code;
}

public String getMaintenance_status() {
    return maintenance_status;
}

public void setMaintenance_status(String maintenance_status) {
    this.maintenance_status = maintenance_status;
}

public String getPhysical_status() {
    return physical_status;
}

public void setPhysical_status(String physical_status) {
    this.physical_status = physical_status;
}
}

我有这种方法应将所有csv内容加载到cards List中，然后将数据放入Map

public static Map<String, Card> getAllCards(String fileLocation) {
        log.logInfo("getAllCards  started!");
        long totalTime = System.currentTimeMillis();
        Map<String, Card> map = new HashMap<>();
        try (
                Reader reader = Files.newBufferedReader(Paths.get(fileLocation))
        ) {
            CsvToBean<Card> csvToBean = new CsvToBeanBuilder(reader)
                    .withSeparator('¦')
                    .withType(Card.class)
                    .withIgnoreLeadingWhiteSpace(true)
                    .build();

            List<Card> cards = csvToBean.parse();
            System.out.println(cards.size());//1.535.232
            for(Card card: cards) {
                Card cardObj = new Card(card.getObject_id(),card.getType(),card.getName(), card.getParent_id(),
                        card.getManufacturer(), card.getPosition_code(), card.getMaintenance_status(),card.getPhysical_status());
                map.put(card.getObject_id(), cardObj);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println(map.get("OBJECT_ID"));//null
        System.out.println(map.size());//1 as it inserts only one null key
        log.logInfo("getAllCards completed in " + ((double) (System.currentTimeMillis() - totalTime) / 1000) + " sec.");
        return map;
    }

问题在于卡列表包含具有所有空值的对象的列表。大小正确，因此它正在读取csv文件，但未填充数据。知道发生了什么吗？

Answer 1

就我而言，我错误地实例化了 InputStreamReader。

接收文件为 MultipartFile，我所做的只是 new InputStreamReader(csvFile.getInputStream())。

我会尝试将您的 reader 实例更改为 FileReader new FileReader("yourfile.csv")。

OpenCSV parse（）返回具有空值的对象

1 个答案: