java.lang.ClassCastException : java. lang.String 无法转换为 java.util.Vector

Question

我有 XML 解析的数据，我正在尝试将其添加到 DefaultTableModel 中。 根据文档，DefaultTableModel 将 Vectors 或 Object[] 作为参数。

但是当我使用 Vector 时，我得到了这个异常:

java.lang.ClassCastException: java.lang.String cannot be cast to java.util.Vector

这是我用来解析并添加到 vector 中的类。

public class PropXMLParsing {

    static PropXMLParsing instance = null;

    private Vector<String> header = new Vector<String>();
    private Vector<String> data = new Vector<String>();

    public static PropXMLParsing getInstance() {

        if (instance == null) {

            instance = new PropXMLParsing();
            try {
                instance.ParserForObjectTypes();
            } catch (SAXException e) {

                e.printStackTrace();
            } catch (IOException e) {

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

                e.printStackTrace();
            }

        }

        return instance;

    }

    public void ParserForObjectTypes() throws SAXException, IOException,
            ParserConfigurationException {

        try {
            FileInputStream file = new FileInputStream(new File(
                    "xmlFiles/CoreDatamodel.xml"));

            DocumentBuilderFactory builderFactory = DocumentBuilderFactory
                    .newInstance();

            DocumentBuilder builder = builderFactory.newDocumentBuilder();

            Document xmlDocument = builder.parse(file);

            XPath xPath = XPathFactory.newInstance().newXPath();

            String expression = "//prop/*";
            NodeList nodeList = (NodeList) xPath.compile(expression).evaluate(
                    xmlDocument, XPathConstants.NODESET);
            for (int i = 0; i < nodeList.getLength(); i++) {

                System.out.println(nodeList.item(i).getFirstChild()
                        .getNodeValue());

                data.addElement(nodeList.item(i).getFirstChild().getNodeValue());
                header.addElement(nodeList.item(i).getFirstChild()
                        .getNodeValue());

            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (XPathExpressionException e) {
            e.printStackTrace();
        }
    }

    public Vector<String> getHeader() {

        return header;
    }

    public Vector<String> getData() {
        return data;
    }

}

最后一行代码是抛出异常的地方。这是来 self 的 GUI 类:

model = new DefaultTableModel(PropXMLParsing.getInstance().getHeader(),
                PropXMLParsing.getInstance().getData());

        table = new JTable(model);

请帮帮我

Answer 1

根据the javadoc for DefaultTableModel ，数据必须是 Vector<Vector<String>> 。此外，您还可以在 DefaultTableModel 构造函数参数中向后获取数据和 header 。