The one minute writer: XML Questions

XML Questions




 XML, the eXtensible Markup Language,
Flexible representation of data allows you to easily send and receive data, and transform data from one format to another. 
Each XML language defines its own grammar, a specific set of rules governing the content and structure of documents written in that language.

A key advantage of XML over other data formats is the ability to convert an XML data set from one form to another in a generic manner. The technology that enables this translation is the eXtensible Stylesheet Language for Transformations (XSLT).


XML validation technologies
The rules of an XML language can be captured in either of two distinct ways. When codified into either a document type definition or an XML schema definition,

Document type definitions
The first and earliest language definition mechanism is the document type definition (DTD).
DEFINITION A document type definition is a text file consisting of a set of rules about the structure and content of XML documents. It lists the valid set of elements that may appear in an XML document, including their order and attributes.

XML Schema definitions
DTDs are quite limited in their ability to constrain the structure and content of XML documents. They cannot handle namespace
conflicts within XML structures or describe complex relationships among documents or elements. DTDs are not modular, and constraints defined for one data element cannot be reused (inherited) by other elements.

An example XML document 


DEFINITION An XML Schema definition (XSD) is an XML-based grammar declaration for XML documents.

XSD is itself an XML language. Using XSD, data constraints, hierarchical relationships, and element namespaces can be specified more completely than with DTDs. XML Schema allows very precise definition of both simple and complex data types, and allows types to inherit properties from other types

XML parsing technologies

DEFINITION An XML parser is a software component that can read and (in most cases) validate any XML document. A parser makes data contained in an XML data structure available to the application that needs to use it.

SAX
SAX is the fastest parsing method for XML, and is appropriate for handling large documents that could not be read into memory all at once.



DOM
In the DOM model, the parser will read in an entire XML data source and construct a treelike representation of it in memory. Under DOM, a pointer to the entire document is returned to the calling application. The application can then manipulate the document, rearranging nodes, adding and deleting content as needed.

the JAXP API enables the use of either DOM or SAX for parsing XML documents in a parser-independent manner. Deciding
which method to use depends on your application’s requirements for speed, data manipulation, and the size of the documents upon which it operates.

XSLT 

XSLT provides a framework for transforming the structure of an XML document. XSLT combines an input XML document with an XSL stylesheet to produce an output document.

Simple Object Access Protocol (SOAP).
DEFINITION: SOAP is a messaging specification describing data encoding and packaging rules for XML-based communication.

The SOAP specification describes how XML messages can be created, packaged, and transmitted between systems.SOAP can be implemented in a synchronous (client/server) or asynchronous fashion. The synchronous method (RPC-style) involves a client explicitly requesting some XML data from a SOAP server by sending a SOAP request message. The server returns the requested data to the client in a SOAP response message.



XPath (Data manipulation and retrieval technologies)
XPath is a language for addressing XML structures that is used by a variety of other XML standards, including XSLT, XPointer, and XQuery. It defines the syntax for creating expressions, which are evaluated against an XML document. For example, a forward slash (/) is a simple XPath expression.

JAXP
JAXP provides a common interface for creating and using the SAX, DOM, and XSLT APIs in Java.


Java Document Object Model (JDOM),
provides a Javacentric API for working with XML data structures. It was designed specifically for Java and provides an easy-to-use object model already familiar to Java
developers.


  1. What is the difference between HTML and XML?
  2. Was XML used in your project? If Yes, why it was decided to use XML ? In shortly, need to know the problem statement and why it was thought to use XML (Merits of XML)?
  3. What XML parser was used in the project ?
  4. Name the XML parser used in the project? and Why ?
  5. What are two types of Parsers?
  6. When would you decide using a DOM parser or SAX parser?
  7. Can you explain steps encountered in parsing an XML?
  8. Can we validate an XML document?
  9. Differentiate between a document, node and element?
  10. What do you understand by DTD?
  11. What do you understand by Schema?
  12. Given an option how would you go about deciding whether to use DTD or Schema?
  13. Advantages of Schema over DTD ?
  14. What is SOAP?
  15. Do you understand the concept of XSLT?
  16. What is namespace?
  17. What do you understand by JAXP?
  18. What is JDOM?
  19. What do you understand by XPATH?
  20. How do convert an XML into PDF or Excel file?

10:41 AM | |

 

1 comments :

Matthew said...

thank u r information

it very useful

u r blog Is very nice

October 16, 2008 7:08 PM  

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