Java中CSV数据转换为带属性的XML：JAXB实现教程

Col1,Col2,Col3,Col4,Col5
All,0,,0,0
All,935,231,0,30
None,1011,257,0,30

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<root>
    <row col1="All" col2="0" col3="" col4="0" col5="0"></row>
    <row col1="All" col2="935" col3="231" col4="0" col5="30"></row>
    <row col1="None" col2="1011" col3="257" col4="0" col5="30"></row>
</root>

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import java.util.ArrayList;
import java.util.List;

/**
 * Represents the root element <root> of the XML document.
 * Contains a list of RowData objects.
 */
@XmlRootElement(name = "root")
@XmlAccessorType(XmlAccessType.FIELD) // JAXB will access fields directly
public class Root {
    // @XmlElementWrapper(name = "rows") // If you want an intermediate <rows> element
    @XmlElement(name = "row") // Each item in the list will be a <row> element
    private List<RowData> rows;

    public Root() {
        this.rows = new ArrayList<>();
    }

    public void addRow(RowData row) {
        this.rows.add(row);
    }

    public List<RowData> getRows() {
        return rows;
    }

    public void setRows(List<RowData> rows) {
        this.rows = rows;
    }
}

/**
 * Represents a single <row> element in the XML, with CSV columns mapped as attributes.
 */
@XmlRootElement(name = "row") // This annotation is technically not needed here if it's an @XmlElement within Root
@XmlAccessorType(XmlAccessType.FIELD) // JAXB will access fields directly
public class RowData {
    @XmlAttribute(name = "col1")
    private String col1;

    @XmlAttribute(name = "col2")
    private String col2; // Use String for flexibility, convert as needed

    @XmlAttribute(name = "col3")
    private String col3;

    @XmlAttribute(name = "col4")
    private String col4;

    @XmlAttribute(name = "col5")
    private String col5;

    // Default constructor for JAXB
    public RowData() {}

    // Constructor to easily create RowData objects from parsed CSV data
    public RowData(String col1, String col2, String col3, String col4, String col5) {
        this.col1 = col1;
        this.col2 = col2;
        this.col3 = col3;
        this.col4 = col4;
        this.col5 = col5;
    }

    // Getters and Setters (optional if using XmlAccessType.FIELD, but good practice)
    public String getCol1() { return col1; }
    public void setCol1(String col1) { this.col1 = col1; }
    public String getCol2() { return col2; }
    public void setCol2(String col2) { this.col2 = col2; }
    public String getCol3() { return col3; }
    public void setCol3(String col3) { this.col3 = col3; }
    public String getCol4() { return col4; }
    public void setCol4(String col4) { this.col4 = col4; }
    public String getCol5() { return col5; }
    public void setCol5(String col5) { this.col5 = col5; }
}

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;

public class CsvParser {

    /**
     * Parses a CSV file and populates a Root object with RowData instances.
     * Assumes the first line is a header and skips it.
     *
     * @param csvFilePath The path to the CSV file.
     * @param delimiter   The delimiter used in the CSV file (e.g., ",").
     * @return A Root object containing parsed CSV data.
     * @throws IOException If an I/O error occurs during file reading.
     */
    public static Root parseCsv(String csvFilePath, String delimiter) throws IOException {
        Root root = new Root();
        try (BufferedReader br = new BufferedReader(new FileReader(csvFilePath))) {
            String line;
            // Read and skip the header line
            br.readLine();

            while ((line = br.readLine()) != null) {
                // Handle potential empty lines
                if (line.trim().isEmpty()) {
                    continue;
                }

                String[] fields = line.split(delimiter, -1); // -1 to keep trailing empty strings

                // Ensure we have enough fields, pad with empty strings if necessary
                String[] paddedFields = Arrays.copyOf(fields, 5);
                for (int i = 0; i < paddedFields.length; i++) {
                    if (paddedFields[i] == null) {
                        paddedFields[i] = ""; // Replace null with empty string
                    }
                }

                try {
                    // Create a RowData object from the parsed fields
                    RowData rowData = new RowData(
                            paddedFields[0],
                            paddedFields[1],
                            paddedFields[2],
                            paddedFields[3],
                            paddedFields[4]
                    );
                    root.addRow(rowData);
                } catch (Exception e) {
                    System.err.println("Error processing CSV line: " + line + ". Skipping. Error: " + e.getMessage());
                }
            }
        }
        return root;
    }
}

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

public class XmlGenerator {

    /**
     * Generates an XML file from a Root object using JAXB Marshaller.
     *
     * @param rootObject The Root object containing the data.
     * @param xmlFilePath The desired path for the output XML file.
     */
    public static void generateXml(Root rootObject, String xmlFilePath) {
        try {
            // Create JAXBContext for the Root and RowData classes
            JAXBContext jaxbContext = JAXBContext.newInstance(Root.class, RowData.class);
            Marshaller jaxbMarshaller = jaxbContext.createMarshaller();

            // Set property to format the output XML nicely
            jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

            // Output XML to console for quick verification
            System.out.println("--- Generated XML (Console Output) ---");
            jaxbMarshaller.marshal(rootObject, System.out);