Question

我想阅读一个xml文件。我找到了一个好的例子，直到xml元素没有任何属性。当然，我试图照顾我如何阅读属性，但它不起作用。

例如

XML

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<car>
<properties>
<test h="1.12" w="4.2">
<colour>red</colour>
</test>
</properties>
</car>

Java代码：

public void readXML(String file) {
    try {

        File fXmlFile = new File(file);
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory
                .newInstance();
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
        doc = dBuilder.parse(fXmlFile);
        doc.getDocumentElement().normalize();

        for (int temp = 0; temp < nList.getLength(); temp++) {

            Node nNode = nList.item(temp);
            if (nNode.getNodeType() == Node.ELEMENT_NODE) {

                Element eElement = (Element) nNode;

                System.out.println("test : "
                        + getTagValue("test", eElement));
                System.out.println("colour : " + getTagValue("colour", eElement));

            }
        }

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

public String getTagValue(String sTag, Element eElement) {
    NodeList nlList = eElement.getElementsByTagName(sTag).item(0)
            .getChildNodes();


    Node nValue = (Node) nlList.item(0);
            System.out.println(nValue.hasAttributes());

    if (sTag.startsWith("test")) {
        return eElement.getAttribute("w");

    } else {
        return nValue.getNodeValue();
    }

}

输出：

错误

测试：

假

颜色：红色

我的问题是，我无法打印出属性。我怎么能得到属性？

Answer 1

你的代码有很多错误;未声明的变量和看似疯狂的算法。我重写了它并且它有效：

import java.io.File;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public final class LearninXmlDoc
{
    private static String getTagValue(final Element element)
    {
        System.out.println(element.getTagName() + " has attributes: " + element.hasAttributes());

        if (element.getTagName().startsWith("test"))
        {
            return element.getAttribute("w");

        }
        else
        {
            return element.getNodeValue();
        }
    }

    public static void main(String[] args)
    {
        final String fileName = "c:\\tmp\\test\\domXml.xml";

        readXML(fileName);
    }

    private static void readXML(String fileName)
    {
        Document document;
        DocumentBuilder documentBuilder;
        DocumentBuilderFactory documentBuilderFactory;
        NodeList nodeList;
        File xmlInputFile;

        try
        {
            xmlInputFile = new File(fileName);
            documentBuilderFactory = DocumentBuilderFactory.newInstance();
            documentBuilder = documentBuilderFactory.newDocumentBuilder();
            document = documentBuilder.parse(xmlInputFile);
            nodeList = document.getElementsByTagName("*");

            document.getDocumentElement().normalize();

            for (int index = 0; index < nodeList.getLength(); index++)
            {
                Node node = nodeList.item(index);
                if (node.getNodeType() == Node.ELEMENT_NODE)
                {
                    Element element = (Element) node;

                    System.out.println("\tcolour : " + getTagValue(element));
                    System.out.println("\ttest : " + getTagValue(element));
                    System.out.println("-----");
                }
            }
        }
        catch (Exception exception)
        {
            exception.printStackTrace();
        }
    }
}

Answer 2

如果您有该文件的架构，或者可以制作一个架构you can use XMLBeans。顾名思义，它使Java bean脱离了XML。然后你可以使用getter获取属性。

Answer 3

使用dom4j库。

InputStream is = new FileInputStream(filePath);

SAXReader reader = new SAXReader();
org.dom4j.Document doc = reader.read(is);
is.close();
Element content = doc.getRootElement();  //this will return the root element in your xml file
List<Element> methodEls = content.elements("element"); // this will retun List of all Elements with name "element"
Attribute attrib = methodEls.get(0).attribute("attributeName"); // this is the "attributeName" attribute of first element with name "element"

Answer 4

如果您只是想要获取属性（例如config / ini文件），我建议您使用java属性文件。

http://docs.oracle.com/javase/tutorial/essential/environment/properties.html

如果您只想读取文件，请创建一个新的fileReader并将其放入bufferedReader。

BufferedReader in = new BufferedReader(new FileReader("example.xml"));

使用Element.getAttribute（）无法获取元素值

4 个答案: