Question

我有以下XML：

     <ConfigGroup Name="Replication">
        <ValueInteger Name="ResponseTimeout">10</ValueInteger>
        <ValueInteger Name="PingTimeout">2</ValueInteger>
        <ValueInteger Name="ConnectionTimeout">10</ValueInteger>
        <ConfigGroup Name="Pool">
            <ConfigGroup Name="1">
                <ValueString Encrypted="false" Name="Host">10.20.30.40</ValueString>
                <ValueInteger Name="CacheReplicationPort">8899</ValueInteger>
                <ValueInteger Name="RadiusPort">12050</ValueInteger>
                <ValueInteger Name="OtherPort">4868</ValueInteger>
            </ConfigGroup>
            <ConfigGroup Name="2">
                <ValueString Encrypted="false" Name="Host">10.20.30.50</ValueString>
                <ValueInteger Name="CacheReplicationPort">8899</ValueInteger>
                <ValueInteger Name="RadiusPort">12050</ValueInteger>
                <ValueInteger Name="OtherPort">4868</ValueInteger>
            </ConfigGroup>
        </ConfigGroup>
     </ConfigGroup>

我只是想知道在Java中解析这个XML的最简单方法是什么 - 我想要两个主机元素的值（例如10.20.30.40和10.20.30.50）。请注意，可能有两个以上的池条目（或根本没有）。

我无法找到如何使用各种XML解析器进行Java的简单示例。

非常感谢任何帮助。

谢谢！

Answer 1

Java XPath API允许轻松完成。以下xpath表达式

//ValueString[@Name='Host']

应符合您的要求。以下是如何将其与API一起使用：

Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(yourXml.getBytes());
XPath xpath = XPathFactory.newInstance().newXPath();
NodeList nodeList = (NodeList) xpath.compile("//ValueString[@Name='Host']").evaluate(doc, XPathConstants.NODESET);
for (int i = 0; i < nodeList.getLength(); i++) {
  String ip = ((Element) nodeList.item(i)).getTextContent();
  // do something with your ip
}

Answer 2

搜索您正在寻找的内容的最简单方法是XPath。

try {

    //Load the XML File
    DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
    domFactory.setNamespaceAware(true);
    DocumentBuilder builder = domFactory.newDocumentBuilder();
    Document configuration = builder.parse("configs.xml");

    //Create an XPath expression
    XPathFactory xpathFactory = XPathFactory.newInstance();
    XPath xpath = xpathFactory.newXPath();
    XPathExpression expr = xpath.compile("//ConfigGroup/ValueString[@Name='Host']/text()");

    //Execute the XPath query
    Object result = expr.evaluate(configuration, XPathConstants.NODESET);
    NodeList nodes = (NodeList) result;

    //Parse the results
    for (int i = 0; i < nodes.getLength(); i++) {
        System.out.println(nodes.item(i).getNodeValue()); 
    }
} catch (ParserConfigurationException e) {
    System.out.println("Bad parser configuration");
    e.printStackTrace();
} catch (SAXException e) {
    System.out.println("SAX error loading the file.");
    e.printStackTrace();
} catch (XPathExpressionException e) {
    System.out.println("Bad XPath Expression");
    e.printStackTrace();
} catch (IOException e) {
    System.out.println("IO Error reading the file.");
    e.printStackTrace();
}

XPath表达式

"//ConfigGroup/ValueString[@Name='Host']/text()"

在XML中的任何位置查找ConfigGroup元素，然后在ConfigGroup元素中查找ValueString元素，这些元素具有值为“Host”的Name属性。 @ Name = Host就像是名为ValueString的元素的过滤器。最后的text（）返回所选元素的文本节点。

Answer 3

File file = new File("some/path");
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document document = db.parse(file);
NodeList list = document.getElementsByTagName("name/of /your/ element");
// its return NodeList of all descendant Elements with a given tag name, in document order.  
for (int i = 0; i < list .getLength(); i++) {
     System.out.println(list.item(i).getNodeName()+" = "+list.item(i).getNodeValue());
 }

Answer 4

您可以使用SAXON

String vs_source = "Z:/Code_JavaDOCX/1.xml";
Processor proc = new Processor(false);
net.sf.saxon.s9api.DocumentBuilder builder = proc.newDocumentBuilder();
XPathCompiler xpc = proc.newXPathCompiler();
try{
            XPathSelector selector = xpc.compile("//output").load();
            selector.setContextItem(builder.build(new File(vs_source)));
            for (XdmItem item: selector) 
                {
                    System.out.println(item.getStringValue());
                }
        }   
catch(Exception e)
        {
            e.printStackTrace();
        }

用Java解析这个XML的最简单方法？

4 个答案: