Parsing xml with dom4j or jdom or anyhow
I wanna read feed entries and I'm just stuck now. Take this for example : https://stackoverflow.com/feeds/question/2084883 lets say I wanna read all the summary node value inside each entry node in document. How do I do that? I've changed many variations of code this one is closest to what I want to achieve I think :
Element entryPoint = document.getRootElement();
Element elem;
for(Iterator iter = entryPoint.elements().iterator(); iter.hasNext();){
elem = (Element)iter.next();
System.out.println(elem.getName());
}
It goes trough all nodes in xml file and writes their name. Now what I wanted to do next is
if(elem.getName().equals("entry"))
to get only the entry nodes, how do I get elements of the entry nodes, and how to get let say summary and its value? tnx
Question: how to get values of summary nodes from thi开发者_JS百科s link
Have you tried jdom? I find it simpler and convenient.
http://www.jdom.org/
To get all children of an xml element, you can just do
SAXBuilder sb = new SAXBuilder();
StringReader sr = new StringReader(xmlDocAsString);
Document doc = sb.build(sr);
Element root = doc.getRootElement();
List l = root.getChildren("entry");
for (Iterator iter = l.iterator(); iter.hasNext();) {
...//do whatever...
}
Here's how you'd do it using vanilla Java:
//read the XML into a DOM
StreamSource source = new StreamSource(new StringReader("<theXml></theXml>"));
DOMResult result = new DOMResult();
Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.transform(source, result);
Node root = result.getNode();
//make XPath object aware of namespaces
XPath xpath = XPathFactory.newInstance().newXPath();
xpath.setNamespaceContext(new NamespaceContext(){
@Override
public String getNamespaceURI(String prefix) {
if ("atom".equals(prefix)){
return "http://www.w3.org/2005/Atom";
}
return null;
}
@Override
public String getPrefix(String namespaceURI) {
return null;
}
@Override
public Iterator getPrefixes(String namespaceURI) {
return null;
}
});
//get all summaries
NodeList summaries = (NodeList) xpath.evaluate("/atom:feed/atom:entry/atom:summary", root, XPathConstants.NODESET);
for (int i = 0; i < summaries.getLength(); ++i) {
Node summary = summaries.item(i);
//print out all the attributes
for (int j = 0; j < summary.getAttributes().getLength(); ++j) {
Node attr = summary.getAttributes().item(j);
System.out.println(attr.getNodeName() + "=" + attr.getNodeValue());
}
//print text content
System.out.println(summaries.item(i).getTextContent());
}
if(elem.getName() == "entry")
I have no idea whether this is your problem (you don't really state what your problem is), but never test string equality with --
. Instead, use equals()
:
if(elem.getName().equals("entry"))
A bit late but it might be useful for people googling...
There is a specialized API for dealing with RSS and Atom feeds in Java. It's called Rome, can be found here :
http://java.net/projects/rome/
It is really quite useful, it makes easy to read feed whatever the RSS or Atom version. You can also build feeds and generate the XML with it though I have no experience with this feature.
Here is a simple example that reads a feed and prints out the description nodes of all the entries in the feed :
URL feedSource = new URL("http://....");
feed = new SyndFeedInput().build(new XmlReader(feedSource));
List<SyndEntryImpl> entries = (List<SyndEntryImpl>)feed.getEntries();
for(SyndEntryImpl entry : entries){
System.out.println(entry.getDescription().getValue());
}
Simple enough.
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