Develop Reference

paremetrize part of xml attribute value

I'm unmarshaling a couple of large XML files.
they have the common part and I decided to write the common parts in separate XML file and then include it using xi:include tag.
it looks like this:
<tag1>
<tag2>
</tag2>
<tag3>
</tag3>
<xi:include href = "long/common/part/of/partial/xml/file1"/>
<xi:include href = "long/common/part/of/partial/xml/file2"/>
</tag1>
at this moment I would like to parametrize the long/common/part.
I tried to define a variable using xsl:variable like this
<xsl:variable name="test">
"long/common/part/of/partial/xml/"
</xsl:variable>
but the assigning value to href was a problem, neither the
<xi:include href = "{$test}"/>
or
<xi:include href = <xsl:value-of select="test"/>
wasn't working.
Is there a way to assign value to XML attribute?

You're mixing XInclude, XSLT, and ad-hoc {$var} syntax (not part of XML) here. What you can do to parametrize a href value in XInclude elements is to use an entity reference (XML's and SGML's mechanism for text substitution variables among other things):
<xi:include href="&href-value;"/>
where href-value must be bound to the string long/common/part/of/partial/xml/file1 either programmatically, or (preferably) by declaring it in the prolog eg:
<!DOCTYPE tag1 [
<!ENTITY href-value "long/common/part/of/partial/xml/file1">
]>
<tag1>
<xi:include href = "&href-value;"/>
</tag1>
However, since now you're using entity references anyway, you can achieve just the same with just entities, and without XInclude at all:
<!DOCTYPE tag1 [
<!ENTITY common-part SYSTEM "long/common/part/of/partial/xml/file1">
]>
<tag1>
&common-part;
</tag1>
This pulls the content of long/common/part/of/partial/xml/file1 into the common-part entity, then references that value in content, with the XML parser treating the document as if the replacement value for common-part (eg. whatever is stored in long/common/part/of/partial/xml/file1) had been specified directly in the document.
Hope this isn't too confusing; there's a general explanation how entities in XML and SGML work in this answer

Parse XML in which tag name is not fixed

It is easy to parse XML in which tags name are fixed. In XStream, we can simply use #XStreamAlias("tagname") annotation. But how to parse XML in which tag name is not fixed. Suppose I have following XML :
<result>
<result1>
<fixed1> ... </fixed1>
<fixed2> ... </fixed2>
</result1>
<result2>
<item>
<America>
<name> America </name>
<language> English </language>
</America>
</item>
<item>
<Spain>
<name> Spain </name>
<language> Spanish </language>
</Spain>
</item>
</result2>
</result>
Tag names America and Spain are not fixed and sometimes I may get other tag names like Germany, India, etc.
How to define pojo for tag result2 in such case? Is there a way to tell XStream to accept anything as alias name if tag name is not known before-hand?

if it is ok for you to get the tag from inside the tag itself (field 'name'), using Xpath, you can do:
//result2/*/name/text()
another option could be to use the whole element, like:
//result2/*
or also:
//result2/*/name()

Some technologies (specifically, data binding approaches) are optimized for handling XML whose structure is known at compile time. Others (like DOM and other DOM-like tree models - JDOM, XOM etc) are designed for handling XML whose structure is not known in advance. Use the tool for the job.
XSLT and XQuery try to blend both. In their schema-aware form, they can take advantage of static structure information when it is available. But more usually they are run in "untyped" mode, where there is no a-priori knowledge of element names or structure, and everything is handled as it comes. The XSLT rule-based processing paradigm is particularly well suited to "semi-structured" XML whose content is unpredictable or variable.

How to add multiple attribute values to xml file in JAVA using DOM

I have One XML Like
<root>
<name id="1">Abc</name>
<salary>25000</salary>
</root>
I want something like this
<root>
<name id="1,2">Abc</name>
<salary>25000</salary>
</root>
I am able to create the attribute by using DOM parser as:
Document doc = _docBuilder.newDocument();`
Attr attr = doc.createAttribute("id");
attr.setValue("1");
name.setAttributeNode(attr);
How can I get multiple attribute values for the same attribute.

XML does not support attributes with multiple values.
You could certainly do: attr.setValue("1,2");
However that really isn't very XML friendly. Also, you probably shouldn't have more than one value for an id. You may wish to consider something like this:
<thing>
<name>Abc</name>
<reference_ids>
<id>1</id>
<id>2</id>
</reference_ids>
</thing>

DOM parser for non xml

i want to parse the following type of text. Example1
<root>my name is <j> <b> mike</b> </j> </root>
example 2
<root> my name is <mytag1 attribute="val" >mike</mytag1> and yours is <mytag2> john</mytag2> </root>
can i parse it using a DOM parser?I will not have the same format evry time .I can have different formats in which the tags are nested.I dont know the format in advance.

Both these examples are valid XML documents so there's no reason you can;t do this.
If your XML is very simple, especially if it combines text and tags together, you may want to run it via an XSL transformation first, to have a format easier to parse or to convert it to other format, such as HTML.

You can use a DOM parser for the examples you've given - they're valid XML. However, you wouldn't be able to use it for non-XML as per your subject line.
When you say you can have "different formats in which the tags are nested" what exactly do you mean? If it's always simple nesting, e.g.
<root>
<tag1>
<tag2>
<tag3>
Stuff
</tag3>
</tag2>
</tag1>
</root>
Then that will be fine. However, an XML parser won't like markup where an "outer" tag is closed before an "inner" one:
<root>
<tag1>
<tag2>
Stuff
</tag1> <!-- Invalid -->
</tag2>
</root>

How do I select something with a blank namespace with Jaxen?

I have the following xml:
<config xmlns="http://www.someurl.com">
<product>
<brand>
<content />
</brand>
</product>
</config>
I'm reading it nicely into JDOM.
However, when I try to use Jaxen to grab the contents, I can't seem to get anything.
Here's an example of what doesn't seem to work:
XPath xpath = new JDOMXPath("config");
SimpleNamespaceContext namespaceContext = new SimpleNamespaceContext();
namespaceContext.addNamespace("", "http://www.someurl.com");
xpath.setNamespaceContext(namespaceContext);
assert xpath.selectNodes(document).size() > 0 : "should find more than 0";
This assertion always fails.
What am I doing wrong?

You have to assign a prefix. Make that call addNamespace("hopfrog", "http://...");
Then make the XPath ("hopfrog:config");
Keep in mind that the prefixes in XML aren't part of the real data model. The real data model assigns a URL, possibly blank, to each element and attribute. You can use any prefix you want in XPath so long as it's bound to the right URL. Since the URL you want it blank, you bind a prefix to 'blank'.