Develop Reference

Getting null values from XPath query

I have this xml file:
<?xml version="1.0" encoding="UTF-8"?>
<iet:aw-data xmlns:iet="http://care.aw.com/IET/2007/12" class="com.aw.care.bean.resource.MessageResource">
<iet:metadata filter=""/>
<iet:message-resource>
<iet:message>some message 1</iet:message>
<iet:customer id="1"/>
<iet:code>edi.claimfilingindicator.11</iet:code>
<iet:locale>iw_IL</iet:locale>
</iet:message-resource>
<iet:message-resource>
<iet:message>some message 2</iet:message>
<iet:customer id="1"/>
<iet:code>edi.claimfilingindicator.12</iet:code>
<iet:locale>iw_IL</iet:locale>
</iet:message-resource>
.
.
.
.
</iet:aw-data>
Using this code below i'm getting over the data and finding what I need.
try {
FileInputStream fileIS = new FileInputStream(new File("resources\\bootstrap\\content\\MessageResources_iw_IL\\MessageResource_iw_IL.ctdata.xml"));
DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
builderFactory.setNamespaceAware(true); // never forget this!
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document xmlDocument = builder.parse(fileIS);
XPath xPath = XPathFactory.newInstance().newXPath();
String query = "//*[local-name()='message-resource']//*[local-name()='code'][contains(text(), 'account')]";
NodeList nodeList = (NodeList) xPath.compile(query).evaluate(xmlDocument, XPathConstants.NODESET);
System.out.println("size= " + nodeList.getLength());
for (int i = 0; i < nodeList.getLength(); i++) {
System.out.println(nodeList.item(i).getNodeValue());
}
}
catch (Exception e){
e.printStackTrace();
}
The issue is that i'm getting only null values while printing in the for loop, any idea why it's happened?
The code needs to return a list of nodes which have a code and message fields that contains a given parameters (same as like SQL query with two parameters with operator of AND between them)

Check the documentation:
https://docs.oracle.com/javase/7/docs/api/org/w3c/dom/Node.html
getNodeValue() applied to an element node returns null.
Use getTextContent().
Alternatively, if you find DOM too frustrating, switch to one of the better tree models like JDOM2 or XOM.
Also, if you used an XPath 2.0 engine like Saxon, it would (a) simplify your expression to
//*:message-resource//*:code][contains(text(), 'account')]
and (b) allow you to return a sequence of strings from the XPath expression, rather than a sequence of nodes, so you wouldn't have to mess around with nodelists.
Another point: I suspect that the predicate [contains(text(), 'account')] should really be [.='account']. I'm not sure of that, but using text() instead of ".", and using contains() instead of "=", are both common mistakes.

XPATH won't work

I am trying to extract a 'PartyID' from a request using XPath. This request is in the form of XML.
Here is the XML:
<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<soapenv:Body>
<s1:invokerules xmlns:s1="http://rules.kmtool.abc.com"><s1:arg0><![CDATA[<?xml version="1.0" encoding="UTF-8"?>
<kbdInitiateRequest>
<kmTestHeader>
<MessageId>USER1_MSG1</MessageId>
<TestDate>08/07/2008 07:34:15</TestDate>
<TestReference>
<ConductorReference>
<InvokeIdentifier>
<RefNum>USER1_Ref1</RefNum>
</InvokeIdentifier>
</ConductorReference>
</TestReference>
<TestParty>
<ConductorParty>
<Party PartyID="123456789" AgencyID="DUNS">
<TestContact>
<DetailedContact>
<ContactName>Michael Jackson</ContactName>
<Telephone>02071059053</Telephone>
<TelephoneExtension>4777</TelephoneExtension>
<Email>Michal.Jackson#Neverland.com</Email>
<Title>Mr</Title>
<FirstName>Michael</FirstName>
<Initials>MJ</Initials>
</DetailedContact>
</TestContact>
</Party>
</ConductorParty>
<PerformerParty>
<Party PartyID="987654321" AgencyID="DUNS">
</Party>
</PerformerParty>
</TestParty>
</kmTestHeader>
<kmToolMessage>
<controlNode>
<userRequest>INITIATE</userRequest>
</controlNode>
<customer>
<circuitID>000111333777</circuitID>
</customer>
</kmToolMessage>
</kbdInitiateRequest>
]]></s1:arg0>
</s1:invokerules>
</soapenv:Body>
</soapenv:Envelope>
I have a method in my java code called getPartyId(). This method should extract the PartyID from the XML. However I cannot get this method to return the PartyID no matter what XPath query I use, this is where I need help.
Here is the getPartyId method:
private String getPartyId(String xml) throws XPathExpressionException
{
XPathFactory xPathfactory = XPathFactory.newInstance();
XPath xpath = xPathfactory.newXPath();
xpath.setNamespaceContext(new NamespaceContext() {
public String getNamespaceURI(String prefix) {
if (prefix == null) throw new NullPointerException("Null prefix");
else if ("SOAP-ENV".equals(prefix)) return "http://schemas.xmlsoap.org/soap/envelope/";
else if ("xml".equals(prefix)) return XMLConstants.XML_NS_URI;
return XMLConstants.NULL_NS_URI;
}
public String getPrefix(String uri) {
throw new UnsupportedOperationException();
}
public Iterator getPrefixes(String uri) {
throw new UnsupportedOperationException();
}
});
XPathExpression expr = xpath.compile("/SOAP-ENV:Envelope/SOAP-ENV:Body/*/*/*/*/*/*/*/*/*/*/*[local-name()='PartyID']/text()");
InputSource source = new InputSource(new StringReader(xml));
String dunsId = (String) expr.evaluate(source,XPathConstants.STRING);
return dunsId;
}
I believe that the problem lies with the XPathExpression:
XPathExpression expr = xpath.compile("/SOAP-ENV:Envelope/SOAP-ENV:Body/*/*/*/*/*/*/*/*/*/*/*[local-name()='PartyID']/text()");
I have tried a number of alternatives for 'expr' however none of these have worked. Has anyone got any ideas?

Because the xml you need to parse is sitting inside a CDATA block, you'll need to re-parse the value of s1:arg0 before accessing data within it.
You will need to do this in 2 steps
You will need to access the arg0 node in the http://rules.kmtool.abc.com namespace.
Since you don't have a NamespaceContext for this inner xmlns, you can use :
/SOAP-ENV:Envelope/SOAP-ENV:Body/*[local-name()='invokerules']
/*[local-name()='arg0']/text()
You then need to load this value into another InputSource.
The PartyId attribute can be accessed via the path:
kbdInitiateRequest/kmTestHeader/TestParty/ConductorParty/Party/#PartyID
(no need to use local-name() since there aren't any xmlns in the CDATA)

Notice that your inner xml is inside CDATA node.
So basiclly you are trying to query path of an XML inside CDATA.
As this thread state
Xpath to the tag inside CDATA
Seems this is not possible :(
I would suggest take the CData inside the code and parse it into a new XML Document and query that.
Thanks,
Amir

Why I can't take the content of a tag using XPath in a Java method?

I am very new in XPath and I have the following problem:
I have a Java method that receives data from a webservices and these data are in a XML document, so I have to use XPath to take a specific value inside this XML result document.
In particular I have that this is the entire XML output provided by my web service (the web service response):
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Body>
<getConfigSettingsResponse xmlns="http://tempuri.org/">
<getConfigSettingsResult><![CDATA[<root>
<status>
<id>0</id>
<message></message>
</status>
<drivers>
<drive id="tokenId 11">
<shared-secret>Shared 11</shared-secret>
<encoding>false</encoding>
<compression />
</drive>
<drive id="tokenId 2 ">
<shared-secret>Shared 2 </shared-secret>
<encoding>false</encoding>
<compression>false</compression>
</drive>
</drivers>
</root>]]></getConfigSettingsResult>
</getConfigSettingsResponse>
</s:Body>
</s:Envelope>
Now in a Java class I perform the following operations:
XPath xPath; // An utility class for performing XPath calls on JDOM nodes
Element objectElement; // An XML element
//xPath = XPath.newInstance("s:Envelope/s:Body/getVersionResponse/getVersionResult");
try {
// XPath selection:
xPath = XPath.newInstance("s:Envelope/s:Body");
xPath.addNamespace("s", "http://schemas.xmlsoap.org/soap/envelope/");
objectElement = (Element) xPath.selectSingleNode(documentXML);
if (objectElement != null) {
result = objectElement.getValue();
System.out.println("RESULT:");
System.out.println(result);
}
} catch (JDOMException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
and the result of printing the content of the result variable is this output:
RESULT:
<root>
<status>
<id>0</id>
<message></message>
</status>
<drivers>
<drive id="tokenId 11">
<shared-secret>Shared 11</shared-secret>
<encoding>false</encoding>
<compression />
</drive>
<drive id="tokenId 2 ">
<shared-secret>Shared 2 </shared-secret>
<encoding>false</encoding>
<compression>false</compression>
</drive>
</drivers>
</root>
Now my problem is that I want to access only ad the content of the 0 tag, so I want that (in this case) my result variable have to contain the 0 value.
But I can't, I have try to change the previous XPath selection with:
xPath = XPath.newInstance("s:Envelope/s:Body/s:status/s:id");
But doing in this way I obtain that my objectElement is null
Why? What am I missing? What have I to do to obtain that mu result variable contains the content of the id tag?
Tnx
Andrea

Yours "root" node in "CDATA" section. Whole section interpetated as text, and you cannot search it by xPath. You can get text from "objectElement.getValue()", parse it like new XML, and then get tag "id" value with new xPath. Also you can search "objectElement.getValue()" for tag "id" value with regular expression.

Really you should be using the new XPathAPI in JDOM 2.x, and taking pasha701's answer in to consideration, your code should look more like:
Namespace soap = Namespace.getNamespace("s", "http://schemas.xmlsoap.org/soap/envelope/");
Namespace tempuri = Namespace.getNamespace("turi", ""http://tempuri.org/");
XPathExpression<Element> xpath = XPathFactory.instance().compile(
"s:Envelope/s:Body/turi:getConfigSettingsResponse/turi:getConfigSettingsResult",
Filters.element(), null, soap, tempuri);
Element result = xpath.evaluateFirst(documentXML);
String resultxml = result.getValue();
Document resultdoc = new SAXBuilder().build(new StringReader(resultxml));
Element id = resultdoc.getRootElement().getChild("status").getChild("id");

Read element inside element from XML in SAX or Dom

<rootNode>
<Movies>
<Movie id=1>
<title> title1</title>
<Actors>
<Actor>Actor1</Actor>
<Actor>Actor2</Actor>
<Actors>
</Movie>
</Movies>
<performers >
<performer id=100>
<name>name1</name>
<movie idref=1/>
</performer>
</performers>
</rootNode>
Question1: I only want to get the movie under the movies. I tried both of DOM and SAX. It also returns the under performers. How can I avoid this by using SAX or DOM
DOM:
doc.getElementsByTagName("movie");
SAX:
public void startElement(String uri, String localName,String qName,
Attributes attributes) throws SAXException {
if (qName.equalsIgnoreCase("movie"))
Question2: How can I get the element inside element (Actor under movies) by using DOM or SAX?
Basically, what I want to do is output the data in order.
1,title, Actor1,Actor2
100,name1,1

doc.getElementsByTagName("movies")[0].childNodes;
gets you all the movies/movie nodes (watch for lower-/upper-case!). See here http://www.w3schools.com/dom/dom_intro.asp for a short tutorial.

XPath is designed for this type of extraction. For your example file, the query would be something like the following. For simplicity, I assumed your xml was in a res/raw, but in practice you will need to create the InputSource from where ever you are getting your xml.
XPath xpath = XPathFactory.newInstance().newXPath();
String expression = "/rootNode/Movies/Movie";
try {
NodeList nodes = (NodeList) xpath.evaluate(expression, doc,XPathConstants.NODESET);
} catch (XPathExpressionException e) {
e.printStackTrace();
}

How do I remove all selected nodes from an XPath?

I run an XPath in Java with the following xml and code:
<?xml version="1.0" encoding="UTF-8"?>
<list>
<member name="James">
<friendlist>
<friend>0001</friend>
<friend>0002</friend>
<friend>0003</friend>
</friendlist>
</member>
<member name="Jamie">
<friendlist>
<friend>0003</friend>
<friend>0002</friend>
<friend>0001</friend>
</friendlist>
</member>
<member name="Katie">
<friendlist>
<friend>0001</friend>
<friend>0003</friend>
<friend>0004</friend>
</friendlist>
</member>
</list>
Code:
try {
XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression pathExpr = xpath.compile("/list/member/friendlist/friend[.='0003']");
} catch (XPathExpressionException e) {
Of course there are more codes after this but I didn't paste it here because it thought it may confuse even more.
But the idea is I wish to select all the friend nodes that have the ID 0003 from all the members' friendlist nodes, and then remove it from the XML file. The XPath works by selecting all the "friend" nodes that have the value=0003. I know I can use the removeChild() method of the XML Document object. But the problem is how do I remove all of it directly, without going through layers of loops starting from its parent? The removeChild() method needs me to know its parent's parent's parent.
Thanks!
Update:
This is how I used my XPath:
XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression pathExpr = null;
try {
pathExpr = xpath.compile("/list/member/friendlist/friend[.='0003']");
} catch (XPathExpressionException e) {
e.printStackTrace();
}
NodeList list = null;
try {
list = (NodeList) pathExpr.evaluate(xmlDoc, XPathConstants.NODESET);
} catch (XPathExpressionException e) {
e.printStackTrace();
}
The xmlDoc is an XML document object that has an XML file parsed. The XML works fine. It is only the XML not returning a reference but a whole new nodelist, which makes it impossible for me to refer back to its original xml document to do amendments.

for each node in the returned NodeList:
n.getParentNode().removeChild(n);

I don't understand why the returned nodelist's nodes are returning null for parentNode().
But you could try first selecting all the parents of the nodes you want to remove, with this XPath expression:
"/list/member/friendlist[friend[.='0003']]"
or the equivalent,
"/list/member/friendlist[friend = '0003']]"
Then iterate through the resulting nodelist, and in the context of each one, query for nodes matching the XPath expression
"friend[.='0003']"
That will give you a parent node and a child node to use with removeChild().

Have a look on XUpdate. It's not pretty, but it works.