java - 如何使用 DOM 正确解析我的 csv 文件？

Question

我已经设法让文件输出 XML。但是由于某种原因，当parentLocalityName中不存在元素时，只有结束标记会像这样出现，正如您所看到的，只有结束标记出现。我如何更改修改我的代码，以便显示整个标签，但其中没有任何内容？

-<BusStopDetails>

<AtcoCode>0800COC31523</AtcoCode>

<CommonName>Bus Station</CommonName>

<LocalityName>Newquay</LocalityName>

<ParentLocalityName/>

<Latitude>50.4130339395</Latitude>

<Longitude>-5.0856695446</Longitude>

</BusStopDetails>

这是我转换文件的 Java 程序:

import java.io.*;
import java.util.*;
import org.w3c.dom.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.File;

public class CSV2XML {

    // Protected Properties
    protected DocumentBuilderFactory domFactory = null;
    protected DocumentBuilder domBuilder = null;

    // CTOR
    public CSV2XML() {
        try {
            domFactory = DocumentBuilderFactory.newInstance();
            domBuilder = domFactory.newDocumentBuilder();
        } catch (FactoryConfigurationError exp) {
            System.err.println(exp.toString());
        } catch (ParserConfigurationException exp) {
            System.err.println(exp.toString());
        } catch (Exception exp) {
            System.err.println(exp.toString());
        }
    }

    @SuppressWarnings("resource")
    public static void main(String[] args) throws IOException, TransformerException {
        ArrayList<String> busStopInfo = new ArrayList<String>(7);
        // An array list has been used to store the elements from the csv file. They are stored as strings.
        try {

            File file = new File("C:\\Users\\liaml\\OneDrive\\Documents\\CSCU9T4 XML assignment\\lrl00002\\stops.csv");
            BufferedReader readFile = null;

            DocumentBuilderFactory df = DocumentBuilderFactory.newInstance();
            DocumentBuilder db;

            db = df.newDocumentBuilder();

            Document doc = db.newDocument();

            // Root element
            Element rootElement = doc.createElement("BusStops"); // root element "Busstops created"

            doc.appendChild(rootElement);
            readFile = new BufferedReader(new FileReader(file));
            int line = 0; // Represent the lines in the file, starts at the 0th,
                            // increments after every line has been tokenised
                            // for elements line of the file

            String information = null;
            while ((information = readFile.readLine()) != null) {

                String[] tokens = information.split(","); // removes comma until there is no more commas

                String[] row = information.split(","); // store elements after the command, length 6 to store headers



                if (line == 0) {
                    for (String column : row) {
                        busStopInfo.add(column); // This will add column headers from rowValues to busStopInfo ArrayList

                    }
                } else {
                    Element childElement = doc.createElement("BusStopDetails"); // creates child element details

                    rootElement.appendChild(childElement);
                    for (int column = 0; column < busStopInfo.size(); column++) {

                        String header = busStopInfo.get(column);
                        String value = null;

                        if (column < row.length) {
                            value = row[column];
                        } else {
                            value = " ";
                        }

                        Element current = doc.createElement(header); // creates element of current header

                        current.appendChild(doc.createTextNode(value)); // creates placement for value

                        childElement.appendChild(current); // adds current value of the header into child element details


                        // Save the document to the disk file
                        TransformerFactory tranFactory = TransformerFactory.newInstance();
                        Transformer aTransformer = tranFactory.newTransformer();
                        aTransformer.setOutputProperty(OutputKeys.INDENT, "yes");
                        aTransformer.setOutputProperty(OutputKeys.METHOD, "xml");
                        aTransformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
                        Source src = new DOMSource(doc);
                        information = ("C:\\Users\\liaml\\OneDrive\\Documents\\CSCU9T4 XML assignment\\lrl00002\\stops.xml");
                        Result dest = new StreamResult(new File(information));
                        aTransformer.transform(src, dest);


                        if (line >= 0) {
                            System.out.println("CSV File has been successfully converted to XML File & Stored in Zip Folder "
                                    + "(" + String.valueOf(line) + " row)");
                        } else {
                            System.out.println(
                                    "Error while converting input CSV File " + args[0] + " to output XML File " + args[1] + " ");
                        }

                    }
                }
                line++;
            }
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        }

    }
}

Answer 1

<ParentLocalityName/>是一个空标签。
</ParentLocalityName>是结束标签。
不是同一件事。

空标签 ( see XML spec ) 是开始标签和结束标签的简写。

<ParentLocalityName></ParentLocalityName>
<ParentLocalityName/>

上面两行的意思完全一样，解析后无法区分。

顺便说一句:您的标题是假的:您无法使用 DOM 来解析 CSV 文件。
您正在读取 CSV 文件并使用 DOM写入 XML。