Interview Questions.

Q1. What Is Jdom Parser?

JDOM is an open source, java based totally library to parse XML report and it is typically java developer pleasant API.

Q2. What Is A Sax Parser?

SAX Parser is an occasion-based parser for xml files.

Q3. What Dom Stands For?

DOM stands for Document Object Model.

Q4. Can We Create An Xml Document Using Stax Parser?

Yes! Using StAX parser, we will parse, regulate and create a XML file.

Q5. What Is A Stax Parser?

StAX is a JAVA primarily based API to parse XML report in a comparable manner as SAX parser does but StAX is a PULL API wherein as SAX is a PUSH API. It me in case of StAX parser, consumer application need to invite StAX parser to get information from XML whenever it desires but in case of SAX parser, client software is needed to get facts while SAX parser notifies the consumer application that facts is to be had.

Q6. What Are The Benefits Of Jdom Parser?

It is java optimized, it uses java series like List and Arrays. It works with DOM and SAX APIs and combines the exceptional of the two. It is of low memory footprint and is almost as fast as SAX.

Q7. What Are The Disadvantages Of Stax Parser?

We haven't any random get entry to to an XML document seeing that it's far processed in a ahead-simplest manner

If you want to hold track of statistics the parser has seen or alternate the order of gadgets, you must write the code and store the statistics in your own.

Q8. Can We Create An Xml Document Using Xpath Parser?

No! XPath parser is used to to navigate XML Document best. It is higher to apply DOM parser for developing XML.

Q9. Can We Create An Xml Document Using Sax Parser?

No! Using SAX parser, we will best parse or adjust a XML report.

Q10. Can We Create An Xml Document Using Dom Parser?

Yes! Using DOM parser, we will parse, regulate or create a XML document.

Q11. When Are The Benefits Of Using A Dom4j Parser?

When you parse an XML report with a DOM4J parser, you get the power to get back a tree shape that carries all the elements of your file without impacting the reminiscence footprint of the utility. The DOM4J affords a spread of application features you may use to look at the contents and shape of the record in case document is properly established and its shape is known. DOM4J makes use of XPath expression to navigate thru the XML file.

Q12. Explain Xmleventwriter Class Of Stax Parser?

This interface specifies strategies for developing an event.

Upload(Event occasion) - Add event containing factors to XML.

Q13. What Is Path Expression In Xpath?

XPath uses a course expression to choose node or list of nodes from an xml report. Following is the list of beneficial paths and expression to pick out any node/ list of nodes from an xml file.

Expressions:

node-name: Select all nodes with the given name "nodename"

/: Selection starts offevolved from the root node

//: Selection begins from the current node that suit the selection

.: Selects the contemporary node

..: Selects the discern of the current node

@: Selects attributes

pupil: Example − Selects all nodes with the call "student"

class/scholar:  Example: Selects all pupil elements which can be youngsters of sophistication

//student: Selects all scholar factors no matter wherein they're within the file

Q14. What Is Dom?

DOM stands for Document Object Model and it's far an reputable recommendation of the World Wide Web Consortium (W3C). It defines an interface that permits programs to get admission to and update the fashion, structure,and contents of XML files. XML parsers that assist the DOM enforce that interface.

Q15. Name Some Of The Important Sax Parsing Methods?

ContentHandler Interface specifies the callback strategies that the SAX parser uses to inform an utility program of the additives of the XML record that it has visible.

Void startDocument() - Called at the start of a document.

Void endDocument() - Called on the stop of a record.

Void startElement(String uri, String localName, String qName, Attributes atts) - Called at the start of an element.

Void endElement(String uri, String localName,String qName) - Called at the quit of an detail.

Void characters(char[] ch, int start, int period) - Called when individual records is encountered.

Void ignorableWhitespace( char[] ch, int begin, int length) - Called when a DTD is present and ignorable whitespace is encountered.

Void processingInstruction(String goal, String statistics) - Called when a processing training is recognized.

Void setDocumentLocator(Locator locator)) - Provides a Locator that can be used to discover positions within the report.

Void skippedEntity(String call) - Called while an unresolved entity is encountered.

Void startPrefixMapping(String prefix, String uri) - Called while a new namespace mapping is defined.

Void endPrefixMapping(String prefix) - Called when a namespace definition ends its scope.

Q16. When Are The Advantages Of Using A Dom4j Parser?

DOM4J offers java developers flexibility and clean maintainablity of xml parsing code. It is mild weight and quick API.

Q17. Explain Xmlstreamwriter Class Of Stax Parser?

This interface specifies methods for creating an occasion:

writeStartElement(String localName) - Add begin element of given name.

WriteEndElement(String localName) - Add quit detail of given name.

WriteAttribute(String localName, String price) - Write characteristic to an element.

Q18. Name Some Of The Important Dom4j Classes?

The DOM4J defines numerous Java training.

Here are the most commonplace training:

Document - Represents the entire XML report. A Document object is frequently referred to as a DOM tree.

Element - Represents an XML detail. Element item has methods to manipulate its baby elements,its text, attributes and namespaces.

Attribute Represents an attribute of an detail. Attribute has approach to get and set the cost of attribute. It has figure and characteristic kind.

Node Represents Element, Attribute or ProcessingInstruction

Q19. When You Should Use A Stax Parser?

You need to use a StAX parser whilst:

You can process the XML document in a linear style from the top down.

The document isn't deeply nested.

You are processing a completely huge XML report whose DOM tree could consume too much memory. Typical DOM implementations use ten bytes of memory to symbolize one byte of XML.

The trouble to be solved includes most effective a part of the XML report.

Data is available as quickly as it's miles seen by means of the parser, so StAX works well for an XML report that arrives over a flow.

Q20. Explain Xmlstreamreader Class Of Stax Parser?

This magnificence provide iterator of occasions which can be used to iterate over activities as they occur at the same time as parsing the XML report

int next() - used to retrieve subsequent event.

Boolean hasNext() - used to test in addition occasions exists or no longer

String getText() - used to get text of an element

String getLocalName() - used to get call of an element

Q21. What Sax Stands For?

SAX stands for Simple API for XML.

Q22. What Are The Advantages Of Dom Parsing?

The DOM is a not unusual interface for manipulating report systems. One of its layout desires is that Java code written for one DOM-compliant parser have to run on any other DOM-compliant parser with out changes.

Q23. Name Some Of The Parsers Which Are Commonly Used To Parse Xml Documents?

Following are various forms of parsers which might be typically used to parse XML documents:

Dom Parser - Parses the document by way of loading the whole contents of the document and growing its whole hiearchical tree in memory.

SAX Parser - Parses the document on event primarily based triggers. Does now not load the complete report into the memory.

JDOM Parser - Parses the report in comparable style to DOM parser but in greater simpler manner.

StAX Parser - Parses the record in comparable fashion to SAX parser but in more green manner.

XPath Parser - Parses the XML primarily based on expression and is used extensively in conjuction with XSLT.

DOM4J Parser - A java library to parse XML, XPath and XSLT using Java Collections Framework , presents aid for DOM, SAX and JAXP.

Q24. When To Use A Dom4j Parser?

You ought to use a DOM4J parser while:

You want to recognise lots approximately the structure of a document

You want to transport parts of the report round (you might need to kind positive factors, as an instance)

You want to apply the facts inside the report more than once

You are a java developer and want to leverage java optimized parsing of XML.

Q25. What Are The Disadvantages Of Using Xml?

Following are the hazards of XML utilization:

Redundant Syntax - Normally XML file contains lot of repeatitive terms.

Verbose-Being a verbose language, XML report size increases the trmission and storage charges.

Q26. Explain Xmleventreader Class Of Stax Parser?

This class provide iterator of activities which may be used to iterate over occasions as they arise even as parsing the XML record.

StartElement asStartElement() - used to retrieve price and attributes of element.

EndElement asEndElement() - referred to as on the stop of a detail.

Characters asCharacters() - may be used to gain characters this kind of CDATA, whitespace and so on.

Q27. What Are The Key Components Of Xpath?

Following are the key additives of XPath:

Structure Definitions - XPath defines the parts of an XML record like element, attribute, text, namespace, processing-training, comment, and record nodes.

Path Expressions XPath offers effective direction expressions choose nodes or listing of nodes in XML documents.

Standard FunctionsXPath offers a rich library of fashionable capabilities for manipulation of string values, numeric values, date and time assessment, node and QName manipulation, collection manipulation, Boolean values and so forth.

Major a part of XSLTXPath is one of the principal element in XSLT standard and is ought to have understanding so that you can paintings with XSLT files.

W3C recommendationXPath is bureaucratic advice of World Wide Web Consortium (W3C).

Q28. Name Some Methods For Processing The Attributes Connected To An Element In Sax Parsing?

Attributes Interface specifies techniques for processing the attributes related to an element.

Int getLength() - Returns number of attributes.

String getQName(int index)

String getValue(int index)

String getValue(String qname)
 

Q29. Can We Create An Xml Document Using Dom4j Parser?

Yes! Using DOM4J parser, we are able to parse, alter and create a XML record.

Q30. Name Some Of The Important Dom4j Methods?

When you're operating with the DOM4J, there are numerous techniques you'll use frequently:

SAXReader.Study(xmlSource)() - Build the DOM4J file from the xml supply.

Document.GetRootElement() - Get the root detail of the XML.

Element.Node(index) - Get the XML node at particular index within the detail.

Element.Attributes() - Get all of the attributes of an element.

Node.ValueOf(@Name) - Get the cost of an characteristic with given call of the detail.

Q31. What Dom Parser Returns?

When you parse an XML file with a DOM parser, you get again a tree structure that includes all of the factors of your document. The DOM affords a spread of features you could use to observe the contents and structure of the record.

Q32. Name Some Of The Important Jdom Classes?

The JDOM defines numerous Java lessons. Here are the maximum commonplace classes :

Document - Represents the complete XML file. A Document object is frequently known as a DOM tree.

Element - Represents an XML detail. Element item has strategies to control its baby factors,its textual content, attributes and namespaces.

Attribute Represents an attribute of an detail. Attribute has approach to get and set the fee of characteristic. It has figure and attribute type.

Text Represents the text of XML tag.

Comment Represents the feedback in a XML file.

Q33. What Are The Advantages Of Jdom Parser?

When you parse an XML report with a JDOM parser, you get the power to get returned a tree shape that contains all the elements of your record without impacting the reminiscence footprint of the software. The JDOM gives a diffusion of application capabilities you can use to look at the contents and structure of the report in case record is nicely structured and its shape is understood.

JDOM offers java builders flexibility and clean maintainablity of xml parsing code. It is mild weight and brief API.

Q34. How A Sax Parser Works?

SAX (the Simple API for XML) is an event-based parser for xml files.Unlike a DOM parser, a SAX parser creates no parse tree. SAX is a streaming interface for XML, which me that packages the usage of SAX receive occasion notifications approximately the XML file being processed an element, and attribute, at a time in sequential order starting on the pinnacle of the document, and ending with the closing of the ROOT element.

Q35. Is Stax Parser A Pull Api?

Yes! StAX is a PULL API.

Q36. What Is Xml Parser?

XML Parser presents way a way to get admission to or regulate information found in an XML document. Java gives more than one options to parse XML report.

Q37. When To Use A Jdom Parser?

You must use a JDOM parser while:

You need to recognise lots about the structure of a report.

You want to transport elements of the document around (you may want to kind positive elements, as an instance).

You need to apply the data in the report more than as soon as.

You are a java developer and need to leverage java optimized parsing of XML.

Q38. Name Some Of The Important Jdom Methods?

When you are operating with the JDOM, there are several strategies you may use frequently:

SAXBuilder.Construct(xmlSource) - Build the JDOM report from the xml supply.

Document.GetRootElement() - Get the foundation element of the XML.

Element.GetName() - Get the name of the XML node.

Element.GetChildren() - Get all of the direct child nodes of an detail.

Node.GetChildren(Name) - Get all the direct toddler nodes with a given name.

Node.GetChild(Name) - Get first toddler node with given call.

Q39. What Is Xml Parsing?

Parsing XML refers to going via XML document to access records or to modify information in one or different way.

Q40. When To Use A Dom Parser?

You ought to use a DOM parser whilst:

You need to realize plenty approximately the structure of a file

You need to transport parts of the report around (you might want to kind sure factors, as an instance)

You want to apply the statistics in the file more than as soon as

Q41. What Are The Advantages Of Using Xml?

Following are the blessings that XML presents:

Technology agnostic - Being simple text, XML is generation unbiased. It can be used by any technology for statistics storage and trmission purpose.

Human readable- XML uses simple text format. It is human readable and comprehensible.

Extensible - in XML, custom tags can be created and used very easily.

Allow Validation - Using XSD, DTD and XML shape can be established without problems.

Q42. Can We Create An Xml Document Using Jdom Parser?

Yes! Using JDOM parser, we can parse, alter and create a XML record.

Q43. What Are The Key Components/interfaces Of Dom Parsing?Call Some Of The Important Dom Parsing Methods.?

When you're working with the DOM, there are numerous methods you may use regularly:

Document.GetDocumentElement() - Returns the foundation detail of the report.

Node.GetFirstChild() - Returns the primary toddler of a given Node.

Node.GetLastChild() - Returns the remaining toddler of a given Node.

Node.GetNextSibling() - These strategies return the following sibling of a given Node.

Node.GetPreviousSibling() - These techniques return the previous sibling of a given Node.

Node.GetAttribute(attrName) - For a given Node, returns the characteristic with the requested name.

Q44. What Xml Stands For?

XML stands for Extensible Markup Language.

Q45. When To Use A Sax Parser?

You have to use a SAX parser while:

You can method the XML report in a linear style from the pinnacle down

The record isn't deeply nested

You are processing a completely big XML record whose DOM tree might eat an excessive amount of reminiscence.Typical DOM implementations use ten bytes of memory to symbolize one byte of XML

The hassle to be solved involves best a part of the XML report

Data is to be had as soon as it's far visible through the parser, so SAX works nicely for an XML file that arrives over a stream

Q46. What Are The Disadvantages Of Sax Parsing?

We haven't any random get right of entry to to an XML report due to the fact it's far processed in a forward-only way

If you need to keep music of information the parser has seen or alternate the order of gadgets, you should write the code and save the facts to your very own

Q47. What Is Xpath?

The XPath is an official advice of the World Wide Web Consortium (W3C). It defines a language to discover statistics in an XML document. It is used to traverse factors and attributes of an XML record. XPath affords diverse sort of expressions which may be used to investigate applicable facts from the XML record.

Q48. What Is Dom4j Parser?

DOM4J is an open supply, java primarily based library to parse XML file and it is tremendously bendy, excessive-overall performance, and reminiscence-green API. It is java optimized, it makes use of java collection like List and Arrays. It works with DOM, SAX, XPath and XSLT. It can parse huge XML file with very low memory footprint.