XPATH from JAXB object - jaxb

Is there a way to get XPATH from the JAXB Object?
Yes,I googled it and found that I have to use #XmlPath over fields.
I'm generating the POJO using xjc command.Is there a way to tell xjc that I need XPATH over my fields?

#XmlPath (see: http://blog.bdoughan.com/2010/07/xpath-based-mapping.html is an extension in the EclipseLink MOXy implementation of JAXB (JSR-222). Currently neither the reference or EclipseLink implementations of JAXB allow this annotation to be generated starting from an XML Schema.

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JAXB Output XML Attributes to be desired order

I am using JAXB classes for writing xml. While marshalling the order of attributes to be displayed in our desired order. Please suggest to solve this one.
My Current Output:
<ELD UID="1000" Designation="SUPERSTRUCTURE" Code="11">
Required Output:
<ELD UID="1000" Code="11" Designation="SUPERSTRUCTURE">
It depends on what JAXB implementation you use, if you're willing to use MOXy then it's possible to implement DescriptionCustomizer.

ObjectFactory Class from Java Beans

Can anyone please tell how to generate the ObjectFactory class from some Java beans ? Remember , I dont have the xsd and hence I cannot use JAXB for the same.
The only class generation that JAXB (JSR-222) implementations do is from XML schema. When starting from Java classes you just need to create a class and annotate it #XmlRegistry. You will need to include this class in the array of classes used to bootstrap the JAXBContext. The main reason for doing this is to leverage the #XmlElementDecl annotation to associated multiple root elements with a class. Is this what you are trying to do?

Does JAXB support reading xml tags dynamcally

Is there any method in jaxb to read the xml tags dynamically.For example i have two xml files both have diffrent tagnames and attributes.I want to read these two xml files using a single method.I don want to use getelementByTagname and all.All i need to read the xml tags dynamically.Does JAXB support this or there is any other concepts which can do this.Thanks in advance
You can create a single JAXBContext that represents multiple models. As long as the root objects are annotated with #XmlRootElement (or #XmlElementDecl) then your JAXB (JSR-222) implementation will instantiate the correct objects based on the XML input.
http://blog.bdoughan.com/2010/08/using-xmlanyelement-to-build-generic.html

JAXB or Xstream on a Jersey Restful application

I want to know which solution is better for a Jersey Rest Web service. In some cases JAXB is not able to handle some types. Is it better to use XStream?
Note: I'm the EclipseLink JAXB (MOXy) lead and a member of the JAXB (JSR-222) expert group.
I want to know which solution is better for a Jersey Rest Web service.
JAXB (JSR-222) is the default binding layer for JAX-RS. This means that if you have the following method, JAXB will automatically be used to convert the return type (Customer) to XML (and JSON when using Jersey).
#GET
#Produces(MediaType.APPLICATION_XML)
#Path("{id}")
public Customer read(#PathParam("id") long id) {
return entityManager.find(Customer.class, id);
}
If you need more control over your JAXBContext you can use a JAX-RS mechanism called ContextResolver:
http://blog.bdoughan.com/2011/04/moxys-xml-metadata-in-jax-rs-service.html
In some cases JAXB is not able to handle some types
JAXB is able to handle all types, either by default or through the use of an XmlAdapter. Below are some examples where an XmlAdapter is used with the Joda-Time types and some immutable domain objects:
http://blog.bdoughan.com/2011/05/jaxb-and-joda-time-dates-and-times.html
http://blog.bdoughan.com/2010/12/jaxb-and-immutable-objects.html
Is it better to use XStream?
Below is a link to a blog entry I wrote where I mapped the same object model to the same XML document using both JAXB and XStream you may be interested in:
http://blog.bdoughan.com/2010/10/how-does-jaxb-compare-to-xstream.html
JAXB implementations such as MOXy also contain many extensions you will find useful such as XPath based mapping (#XmlPath) and an external mapping document:
http://blog.bdoughan.com/2011/09/mapping-objects-to-multiple-xml-schemas.html
For an example of using MOXy as the JAXB provider in Jersey see:
http://blog.bdoughan.com/2010/08/creating-restful-web-service-part-35.html
Depends on your use case - if you think JAXB will be significant limitation, you can use XStream. Btw Jersey recently added support for MOXy, which could help you overcome some corner cases in JAXB Reference impl in JDK.
Pro JAXB
out of the box functionality with Jersey
ability to specify own JAXBContext
stable; lots of tests / support from Jersey/JAXB team
Con JAXB
it doesn't work as expected for some corner cases (java/xml binding has limitations due to different nature of these languages)
Pro XStream:
you probably have some experience with that
Con XStream:
you'll need implement support for it (MessageBodyReaders/Writers) in Jersey

How jaxb marshaller and unmarshallers uses generated classes

I have generated classes using wsimport/wsconsume for my webservice. I am using JAXB marshaller and unmarshaller support. Can any one tell me how these marshaller/unmarshaller uses gnereated classes? say it is geneated - requestFile,Response File,service,ServiceSoap,ObjectFactory, Package-info. Here Service is name of my webservice.
Any help is greatly appreciated.
JAXB uses the annotations on the generated classes to reflectively marshal/unmarshal XML documents. It tries to use sensible defaults if the annotations are missing.
package-info.java is a weird Java5 thing, which allows you to declare package-level annotations. JAXB uses this is do things like declare package-wide type converters, or XML namespaces.
ObjectFactory is a generate class that provides factory methods for the various JAXB types. You usually don't need to use that yourself.
The generated service classes are used by the JAX-WS runtime to assemble the JAXB-bound model objects into actual SOAP requests and responses.

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