Parsing XML to get all child nodes and their data using Java XPATH

问题

Hi I have requirement like parsing xml and get all child nodes and there data between nodes <Employees> and </Employees>

I have xml like:

<?xml version="1.0"?>
<Employees>
    <Employee emplid="1111" type="admin">
        <firstname>test1</firstname>
        <lastname>Watson</lastname>
        <age>30</age>
        <email>johnwatson@sh.com</email>
    </Employee>
    <Employee emplid="2222" type="admin">
        <firstname>Sherlock</firstname>
        <lastname>Homes</lastname>
        <age>32</age>
        <email>sherlock@sh.com</email>
    </Employee>
</Employees>

I need response like

<Employee emplid="1111" type="admin">
        <firstname>test1</firstname>
        <lastname>Watson</lastname>
        <age>30</age>
        <email>johnwatson@sh.com</email>
    </Employee>
    <Employee emplid="2222" type="admin">
        <firstname>Sherlock</firstname>
        <lastname>Homes</lastname>
        <age>32</age>
        <email>sherlock@sh.com</email>
    </Employee>

I have tried below code

 FileInputStream file = new FileInputStream(new File("E:\\test.xml"));

         DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();

         DocumentBuilder builder =  builderFactory.newDocumentBuilder();

         Document xmlDocument = builder.parse(file);

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

         System.out.println("*************************");
         String expression = "/Employees/*";
         System.out.println(expression);
         String email = xPath.compile(expression).evaluate(xmlDocument);
         System.out.println(email);

but I am getting response like

  test1
        Watson
        30
        johnwatson@sh.com

I have used expression like /Employees/* but its not working

can anyone help me in doing this?

回答1:

This would be a possible XSLT transformation:

<xsl:template match="Employees">
   <xsl:copy-of select = "Employee" />
</xsl:template>

回答2:

If you want to serialize a DOM node to a string use e.g.

import  org.w3c.dom.bootstrap.DOMImplementationRegistry;
import  org.w3c.dom.Document;
import  org.w3c.dom.ls.DOMImplementationLS;
import  org.w3c.dom.ls.LSSerializer;

...

DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();

DOMImplementationLS impl = 
    (DOMImplementationLS)registry.getDOMImplementation("LS");

LSSerializer writer = impl.createLSSerializer();
String str = writer.writeToString(node);

So returning a NodeList you could use

     String expression = "/Employees/*";
     System.out.println(expression);
     NodeList elements = (NodeList)xPath.compile(expression).evaluate(xmlDocument, XPathConstants.NODESET);
     for (int i = 0; i < elements.getLength(); i++) 
     {
       System.out.println(writer.writeToString(element.item(i));
     }

回答3:

First, if you want to match each Employee, ideally your XPath expression should be Employee not /Employees/*. If you know the tag name, you also don't need XPath, you can just do xmlDocument.getElementsByTagName("Employee").

If you want to serialize a node to a String, you can use an Transformer, something like this:

Transformer t = TransformerFactory.newTransformer();
NodeList nodes = xmlDocument.getElementsByTagName("Employee");
for(int i = 0; i < nodes.getLength(); i++) {
    StringWriter sw = new StringWriter();
    t.transform(new DOMSource(nodes.item(i)), new StreamResult(sw));
    String serialized = sw.toString();
    System.out.println(serialized);
}

来源：https://stackoverflow.com/questions/32905376/parsing-xml-to-get-all-child-nodes-and-their-data-using-java-xpath