我有这个XML
<Results SchemaVersion="1.0" SchemaType="Results" GroupId="-12345"
xmlns="http://xyz" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance">
<Attempt>
<Time>2007-03-30T15:58:15</Time>
<Message>This is some message</Message>
</Attempt>
<Attempt>
<Time>2007-03-30T15:59:45</Time>
<Message>This is some other message</Message>
</Attempt>
</Results>
我在Java中使用这个代码来解析上面的xml。我想使用xpath查询获取xml中的根元素的属性。我能够检索根元素的值，但不能检索属性。 注意：在这种情况下我不知道属性名称，否则我可以直接访问这些属性
public class Try {
public static void main(String args[]){
try{
DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse("C:/Documents and Settings/tulans/workspace/WebServiceTool/src/main/resources/Input.xml");
XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression expr = xpath.compile("/*");
Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
System.out.println(nodes.item(0).getLocalName());
System.out.println(nodes.item(0).getNodeName());
}catch(Exception e){
System.out.println(e);
}
}
}
我得到以下结果：
Results
Results
我也想要根元素属性：
SchemaVersion="1.0" SchemaType="Results" GroupId="-12345"
xmlns="http://xyz" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance"
答案 0 :(得分：2)
Node类有一个getAttributes方法可以满足您的需求：
NamedNodeMap attributes = nodes.item(0).getAttributes();
for (int i=0, len=attributes.getLenght(); i<len; i++) {
Attr attr = (Attr)attributes.item(i);
System.out.println(attr.getName() + "=" + attr.getValue());
}
答案 1 :(得分：1)
public class Try {
public static void main(String args[]){
try{
DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse("Input.xml");
XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression expr = xpath.compile("/*");
Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
System.out.println(nodes.item(0).getLocalName());
System.out.println(nodes.item(0).getNodeName());
NamedNodeMap attributes = nodes.item(0).getAttributes();
for (int i = 0; i < attributes.getLength(); i++) {
System.out.println(attributes.item(i));
}
}catch(Exception e){
System.out.println(e);
}
}
}
答案 2 :(得分：0)
Don和Jörn已经向您展示了如何访问DOM树中的属性节点;因为您已经要求使用XPath来访问它们，我将展示一个替代方案，您可以简单地使用XPath表达式/*/@*来访问XPath数据模型中根元素的属性节点。但请注意，命名空间声明不是XPath数据模型中的属性节点，因此路径只能找到属性SchemaVersion="1.0" SchemaType="Results" GroupId="-12345"。因此，根据您想要的结果，您最好使用DOM getAttributes而不是XPath。
答案 3 :(得分：0)
public static void executeXMLToCSV() {
File fXmlFile = new File(fileLocation);
List<String> recordIndexCSVList = new ArrayList<String>();
String recordIndexCSV = "";
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder;
try {
dBuilder = dbFactory.newDocumentBuilder();
Document doc = null;
try {
doc = dBuilder.parse(fXmlFile);
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
doc.getDocumentElement().normalize();
NodeList rootsite = doc.getElementsByTagName("sites");
Node rootsiteNode = rootsite.item(0);
NodeList sites = rootsiteNode.getChildNodes();
for (int siteCtr = 0; siteCtr < sites.getLength(); siteCtr++) {
Node siteNode = sites.item(siteCtr);
System.out.println("\nCurrent Element :"
+ siteNode.getNodeName());
if (siteNode.getNodeType() == Node.ELEMENT_NODE
&& "site".equalsIgnoreCase(siteNode.getNodeName())) {
Element eElement = (Element) siteNode;
String siteId = eElement.getAttribute("id");
String siteName = eElement.getAttribute("name");
System.out.println("Staff id : " + siteId);
System.out.println("Staff name : " + siteName);
NodeList categories = siteNode.getChildNodes();
for (int categoryCtr = 0; categoryCtr < categories
.getLength(); categoryCtr++) {
Node categoryNode = categories.item(categoryCtr);
System.out.println("\nCurrent Element :"
+ categoryNode.getNodeName());
Element cElement = (Element) categoryNode;
String categoryId = cElement.getAttribute("id");
String categoryName = cElement.getAttribute("name");
System.out.println("categoryId : " + categoryId);
System.out.println("categoryName : " + categoryName);
NodeList fleets = categoryNode.getChildNodes();
for (int fleetCtr = 0; fleetCtr < fleets.getLength(); fleetCtr++) {
Node fleetNode = fleets.item(fleetCtr);
System.out.println("\nCurrent Element :"
+ fleetNode.getNodeName());
Element fElement = (Element) fleetNode;
String fleetId = fElement.getAttribute("id");
String fleetName = fElement.getAttribute("name");
System.out.println("fleetId : " + fleetId);
System.out.println("fleetName : " + fleetName);
NodeList fleetChilds = fleetNode.getChildNodes();
for (int fleetChildCtr = 0; fleetChildCtr < fleetChilds
.getLength(); fleetChildCtr++) {
Node fleetChild = fleetChilds
.item(fleetChildCtr);
if ("assets".equalsIgnoreCase(fleetChild
.getNodeName())) {
NodeList assets = fleetChild
.getChildNodes();
for (int assetCtr = 0; assetCtr < assets
.getLength(); assetCtr++) {
Node asset = assets.item(assetCtr);
Element aElement = (Element) asset;
String assetId = aElement
.getAttribute("id");
System.out.println("assetId : "
+ assetId);
/*
* Finally prepare a list of csv
* strings... after this loop iterate
* the list and prepare the final string
* by concanating all.
*/
String recordIndexCSV_index = siteId
+ "_" + categoryId + "_"
+ fleetId + "_" + assetId;
String recordIndexCSVString = recordIndexCSV_index
+ delimeter
+ siteId
+ delimeter
+ categoryId
+ delimeter
+ fleetId
+ delimeter + assetId;
recordIndexCSVList
.add(recordIndexCSVString);
}
}
}
}
}
}
}
for (String recordIndexCSVString : recordIndexCSVList) {
if ("".equals(recordIndexCSV)) {
recordIndexCSV = recordIndexCSV + recordIndexCSVString;
} else {
recordIndexCSV = recordIndexCSV + seperator
+ recordIndexCSVString;
}
}
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}