Dom4j - No such namespace prefix - java

I need to create an .xml file but compiller says to me:
No such namespace prefix
I want to get:
<root>
<header>
<etd:name>test</etd:name>
</header>
</root>
My code:
Document document = DocumentHelper.createDocument();
Element root = document.addElement("root", getXmlNamespace()).addAttribute(new QName("xmlns:etd"), "some-url-there");
Element header = root.addElement("header");
header.addElement("etd:name").addText("test");
I've tried with addElement(new QName("etd:name")) but that shows me empty value xmlns="" which i dont want.

Related

Append a XML tag within an XML object

I'm trying to insert a tag inside an XML object.
Tried the SO answer mentioned here in a different way, but couldnt achieve it.
This is what my request XML looks like.
<Root>
<Id>1234</Id>
<Type>2345</Type>
<Value>RootId</Value>
<IdNum>1234-2345</IdNum>
</Root>
And I had to add a tag to it.
<Root>
<Id>1234</Id>
<Type>2345</Type>
<Value>RootId</Value>
<IdNum>1234-2345</IdNum>
<RefId>1234-2345</RefId>
</Root>
My code looks like below:
...
Element rootEle = document.getElementsByTagName("Root").item(0);
NodeList idNode = rootEle.getElementsByTagName("IdNum");
Text refValue = document.createTextNode(rootEle.getElementsByTagName("IdNum").item(0).getTextContent());
Element refElement = document.createElement("RefId");
refElement.appendChild(refValue);
idNode.item(0).getParentNode().insertBefore(refElement,idNode.item(0));
Tried to print the IdNum like below and it is printing the expected result. But the additional tag alone is not getting appended.
rootEle.getElementsByTagName("IdNum").item(0).getTextContent()
Am I missing something?

Why are xmlns="" added to element in Java automatically?

I am creating an XML file using Java.
I created root node using createElemenNS() to createh root node with namespace.
Element root = doc.createElementNS("http://www.myorc.com/schemas", "InvConf");
Then I created a node using createElement() and added it to root node. This node is automatically added with namespace like below.
Element invList = doc.createElement("InvList");
root.appendChild(invList);
<InvConf xmlns="http://www.myorc.com/schemas">
<InvList xmlns="">
...
</InvList>
<InvList xmlns="">
...
</InvList>
<InvList xmlns="">
...
</InvList>
</InvConf>
How to avoid adding the namespace to child nodes ?
I want the final XML to be like the following
<InvConf xmlns="http://www.myorc.com/schemas">
<InvList>
...
</InvList>
<InvList>
...
</InvList>
<InvList>
...
</InvList>
</InvConf>
Found that issues is coming only when xmlparserv2.jar is in CLASSPATH. This is required by some parts for the application. How to resolve this ?
The xmlns="" were added because your child is not in a namespace, and your parent is. To change that, put it in the namespace at the time you create the element.
Change the
createElement("InvList");
To the correct namespace.
As pointed out in comments xmlns="" means that element doesn't have any namespace. E.g. from XML parser point of view following two documents are identical:
<ns:root xmlns:ns="http://namespace.com">
<child/>
</ns:root>
and
<root xmlns="http://namespace.com">
<child xmlns=""/>
</root>
To avoid creation of xmlns="" in elements not belonging to any namespace you can create prefix on upper level element:
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware(true);
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.newDocument();
Element root = doc.createElementNS("http://namespace.com", "root");
root.setPrefix("ns");
Element child = doc.createElementNS("", "child");
root.appendChild(child);
doc.appendChild(root);
This code will create following XML:
<ns:root xmlns:ns="http://namespace.com">
<child/>
</ns:root>
Alternatively you can use following syntax to achieve same result:
Document doc = db.newDocument();
Element root = doc.createElementNS("http://namespace.com", "ns:root");
Element child = doc.createElementNS("", "child");
root.appendChild(child);
doc.appendChild(root);
When commenting out line root.setPrefix("ns"); or creating element without prefix (doc.createElementNS("http://namespace.com", "root");) following XML will be generated:
<root xmlns="http://namespace.com">
<child xmlns=""/>
</root>

How to create XML with declared namespace?

I am creating a xml request using java.
I am new in creating xmls using java.
Here is code:
Document doc = docBuilder.newDocument();
Element rootElement = doc.createElement("UserRequest");
rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:ns0", "https://com.user.req");
rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");
doc.appendChild(rootElement);
// user element
Element user = doc.createElement("User");
rootElement.appendChild(user);
// userAttributes element
Element userAttr = doc.createElement("UserAttributes");
rootElement.appendChild(userAttr);
// name elements
Element name = doc.createElement("Name");
name.appendChild(doc.createTextNode("hello"));
userAttr.appendChild(name);
// value elements
Element value = doc.createElement("Value");
name.appendChild(doc.createTextNode("dude"));
userAttr.appendChild(value);
Expected output:
<?xml version="1.0" encoding="UTF-8"?>
<UserRequest
xmlns:ns0="https://com.user.req"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ns0:UserRequest">
<User/>
<UserAttributes>
<Name>hello</Name>
<Value>dude</Value>
</UserAttributes>
</UserRequest>
Generated output:
<?xml version="1.0" encoding="UTF-8"?>
<UserRequest
xmlns:ns0="https://com.user.req"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
<User/>
<UserAttributes>
<Name>hello</Name>
<Value>dude</Value>
</UserAttributes>
</UserRequest>
How to get correct namespace (as shown at expected section).
There's nothing wrong with the namespaces in your generated output. However this is an accident ... you're using setAttributeNS() to do something it's not intended for.
Read up on XML namespace declarations and namespace prefixes. That will be a lot easier than trying to explain point-by-point why you're not getting what you expected. For example, xmlns is not a namespace prefix, and xsi:type is not a namespace.
Instead of trying to create the desired namespace declarations as if they were normal attributes, delete these two lines
rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:ns0", "https://com.user.req");
rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/",
"xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");
and instead use
rootElement.setAttributeNS("http://www.w3.org/2001/XMLSchema-instance",
"xsi:type", "ns0:UserRequest");
This should give you most of your expected output, except for the ns0 namespace prefix declaration. It won't generate that because you're not using ns0 on any element or attribute. Did you mean to have
<ns0:UserRequest ...
in your expected output?

Prevent JDOM2 from creating xmlns=""

I try to add new <class> elements to a persistence.xml file with JDOM2.
persistenceUnitEl.add(new Element("class").addContent(className));
The problem is that jdom2 always adds xmlns="" to the <class> elements.
How can i prevent this?
removeAttribute("xmlns") does not work and removeNameSpace(el.getNameSpace()) also does not work.
JDOM only adds the xmlns="" if you add child elements to other elements that are already in a namespace. The default Namespace in XML is the one which has no prefix. In the following example:
<root>
<child />
</root>
There are no namespace prefixes, and the default namespace is "".
The above XML snippet is semantically identical to:
<root xmlns="" >
<child />
</root>
The xmlns="" means that, any time you see an element that has no prefix, that you should put it in the 'empty' namespace "".
Now, if you want to put things in a namespace, and have a prefix, you would do:
<ns:root xmlns:ns="http://mynamespace">
<ns:child />
</ns:root>
Note that the root and child elements in the above example are in the namespace http://mynamespace, and that namespace has the prefix ns. The above code would be semantically identical to (has the same meaning as):
<root xmlns="http://mynamespace">
<child />
</root>
In the above example, the default namespace is changed from "" to be http://mynamespace, so now elements that have no prefix are in that default namespace http://mynamespace. To reiterate, the following two documents are identical:
<ns:root xmlns:ns="http://mynamespace">
<ns:child />
</ns:root>
and
<root xmlns="http://mynamespace">
<child />
</root>
Now, what does all of this have to do with your problem?
Well, your element persistenceUnitEl must be in a default namespace that is not "". Somewhere on that element, or on of it's parents, you have something like:
<tagname xmlns="...something....">
<PersistenceUnit>
</PersistenceUnit>
</tagname>
In the above, the PersistenceUnit is in the namespace ...something..... Now, you are asking JDOM to add the element new Element("class") to the document, so you are getting:
<tagname xmlns="...something....">
<PersistenceUnit>
<class xmlns="" />
</PersistenceUnit>
</tagname>
The reason is because you are telling JDOM to put it in the "" namespace (Namespace.NO_NAMESPACE). See the documentation for JDOM here: new Element(String name).
instead, what you want to do, is put it in the same namespace as the parent:
Namespace parentNamespace = persistenceUnitEl.getNamespace();
persistenceUnitEl.add(new Element("class", parentNamespace).addContent(className));
Now, the real question is whether the "class" element actually belongs in the same namespace as the parent, or not. But that is a question only you can answer.
Resources:
Namespace specification
Decent introduction
A tutorial (quite advanced)
JDOM's NamespaceAware documentation
JDOM's FAQ
From my understanding, I think this is what you want.
<RootTagname xmlns="...some namespace....">
<SubTag>
<NewElement yourAttrib="1"/>
</SubTag>
</RootTagname >
This is what you get.
<RootTagname xmlns="...some namespace....">
<SubTag>
<NewElement xmlns="" yourAttrib="1"/>
</SubTag>
</RootTagname >
Use the below snippet to create the new Element
Element newElement = new Element("NewElement", subElement.getNamespace());
Here is the full code.
Namespace namespace = Namespace.getNamespace("prefix", ".....some namespace....");
XPathBuilder<Element> subTagXpathelementBuilder = new XPathBuilder<Element>("//prefix:SubTag", Filters.element());
subTagXpathelementBuilder.setNamespace(namespace);
XPathFactory xpathFactory = XPathFactory.instance();
Document doc = (Document) builder.build(xmlFile);
XPathExpression<Element> xpath = subTagXpathelementBuilder .compileWith(xpathFactory);
List<Element> subElementsList = xpath.evaluate(doc);
for (Element subElement : subElementsList ) {
Element newElement = new Element("NewElement", subElement.getNamespace());
List<Attribute> newElementAttribList = newElement.getAttributes();
newElementAttribList .add(new Attribute("yourAttrib", "1"));
subElement .addContent(newElement);
}

Modify existing XML stylesheet processing instruction in Java

I'm reading an existing XML file and outputting it (using DOM).
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="test"?>
<Books>
<Book name="MyBook" />
</Books>
But how do I modify the XML stylesheet? -> href here set "test".
Something like this should work (untested)
Element root = doc.getDocumentElement();
XPath xpath = XPathFactory.newInstance().newXPath();
String expression = "/processing-instruction('xml-stylesheet')";
ProcessingInstruction pi;
pi = (ProcessingInstruction)xpath.evaluate(expression, doc, XPathConstants.NODE);
pi.setData("type='text/xsl' href='foo.xsl'");
Thats a bit tricky, but why not read the file first into a String and do a replace before sending it via a stream into the dom parser.

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