Interview Questions.

Q1. Why Use Xml Binding?

It’s no longer vital

the whole thing that should be carried out with XML can be carried out with SAX and DOM

It’s simpler

don’t have to write as a great deal code

don’t need to learn SAX and/or DOM

It’ s less mistakes-inclined

all of the features of the schema are applied

don’ t ought to take into account to manually put into effect them

It can allow customization of the XML structure

unlike XMLEncoder and XMLDecoder within the java.Be package deal

Q2. Give Me An Example Of Xml Document?

<?Xml version="1.0" encoding="UTF-8"?>

<cars xmlns="http://www.Withoutbook.Com/cars"

xmlns:xsi="http://www.W3.Org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.Withoutbook.Com/cars cars.Xsd">

<car year="2001">

<make>BMW</make>

<model>Z3</model>

<color>yellow</color>

</car>

<car year="2001">

<make>Honda</make>

<model>Odyssey</model>

<color>green</color>

</car>

<car year="1997">

<make>Saturn</make>

<model>SC2</model>

<color>purple</color>

</car>

</cars>

Q3. What Are The Disadvantages/non-dreams Of Jaxb?

Standardize generated Java:

lessons generated with the aid of distinct JAXB implementations won't be well suited with each other

Preserve XML equivalence:

unmarshalling XML to items and marshalling again to XML may not bring about equal XML

Bind existing JavaBe to schemas:

 can handiest marshal and unmarshal lessons generated by JAXB

can be delivered later

Schema evolution support:

can’ t adjust formerly generated code to help schema modifications

have to generated new code

Allow generated Java to get entry to:

XML factors/attributes now not defined in initial schema

Partial binding:

unmarshalling simplest a subset of an XML record breaks round tripping

Implement every feature of the schema language:

it’ s hard to put into effect all of XML Schema!

Support DTDs:

 that specialize in XML Schema

DTDs were supported in an in advance version, but gained’ t be anymore

equipment for changing DTDs to XML Schemas exist

Q4. Discuss Customization Levels?

Customizations may be made at four levels

international:

described at “pinnacle stage” in a detail

applies to all schema factors inside the source schema and in all blanketed/imported schemas (recursively)

schema:

described at “pinnacle degree” in a element

applies to all schema elements inside the goal namespace of the source schema

definition:

defined in a type or worldwide announcement

applies to all schema factors that reference the type or worldwide statement

issue:

defined in a selected schema element or attribute assertion

applies only to it

Q5. What Is Xml Binding Relationships?

The relationships between the components worried in XML binding (facts binding) are shown underneath schema -> classes XML -> schema Schema generates training.

Objects are instanceof training.

Marshal from objects to XML

Unmarshall from XML to objects

XML validates and conforms to Schema

Q6. Explain The Syntax Of Customization?

Customizations may be laid out in

the XML Schema (our recognition)

a binding declarations XML record (not properly supported by means of RI but)

The XML Schema need to claim

the JAXB namespace and version

xmlns:jxb="http://java.Solar.Com/xml/ns/jaxb"

jxb:version="1.0">

Customization factors are positioned in annotation elements

 <xsd:annotation>

<xsd:appinfo>

 binding declarations

</xsd:appinfo>

</xsd:annotation>

Q7. How To Validate Java Objects?

The graph of Java objects can contain invalid statistics:

may want to arise whilst items created via unmarshalling are modified

ought to occur whilst objects are constituted of scratch

Use a Validator to validate the objects

Example:

Validator v = manufacturing unit.CreateValidator();

attempt 

v.ValidateRoot(vehicles);

v.Validate(vehicle);

 catch (ValidationException e) 

// Handle the validation error defined by means of e.GetMessage().

Other Validator strategies:

boolean setEventHandler(ValidationEventHandler handler)

• handleEvent approach of ValidationEventHandler is referred to as

if validation errors are encountered

default handler terminates marshalling after first mistakes

go back true to maintain validating

return false to terminate with ValidationException

Pass an example of javax.Xml.Bind.Util.ValidationEventCollector (in jaxb-api.Jar) to setEventHandler to collect validation mistakes and question them later as opposed to handling them at some point of validation.

ValidationEventCollector vec =

new ValidationEventCollector();

v.SetEventHandler(vec);

v.Validate(vehicles);

ValidationEvent[] activities = vec.GetEvents();

Q8. Java Example/java Program To Set Object For Generating Xml?

Cars cars = manufacturing unit.CreateCars();

Car car = manufacturing unit.CreateCar();

car.SetColor("blue");

automobile.SetMake("Mazda");

automobile.SetModel("Miata");

automobile.SetYear(BigInteger.ValueOf(2012));

cars.GetCar().Upload(automobile);

automobile = factory.CreateCar();

car.SetColor("red");

vehicle.SetMake("Ford");

car.SetModel("Mustang II");

automobile.SetYear(BigInteger.ValueOf(2011));

automobiles.GetCar().Add(car);

Q9. Give Me An Example Of Xsd?

<?Xml version="1.0" encoding="UTF-8"?>

<xs:schema elementFormDefault="qualified"

xmlns:xs="http://www.W3.Org/2001/XMLSchema"

xmlns="http://www.Withoutbook.Com/cars"

targetNamespace="http://www.Withoutbook.Com/cars">

<xs:complexType name="car">

<xs:sequence>

<xs:element name="make" type="xs:string"/>

<xs:element name="model" type="xs:string"/>

<xs:element name="color" type="xs:string"/>

</xs:sequence>

<xs:attribute name="year" type="xs:positiveInteger" use="required"/>

</xs:complexType>

<xs:element name="cars">

<xs:complexType>

<xs:sequence>

<xs:element name="car" type="car" maxOccurs="unbounded"/>

</xs:sequence>

</xs:complexType>

</xs:element>

</xs:schema>

Q10. What Are The Goals Of Jaxb?

Easy to apply:

require minimal XML expertise

don’ t require SAX/DOM know-how

Customizable:

can customize mapping of XML to Java

Portable:

can alternate JAXB implementation with out converting source code

Deliver quickly:

supply middle capability ASAP

Natural:

 follow fashionable layout and naming conventions in generated Java

Match schema:

easy to identify generated Java components that correspond to schema features

Hide plumbing:

encapsulate implementation of unmarshalling, marshalling and validation

Validation on call for:

validate objects with out requiring marshalling

Preserve object equivalence:

(round tripping)

marshalling items to XML and unmarshalling returned to items outcomes in equivalent objects

Q11. Java Code For Marshalling Java Objects Into Xml?

Example:

Marshaller m = manufacturing unit.CreateMarshaller();

m.SetProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);

Writer fw = new FileWriter(“newCars.Xml”);

m.Marshal(automobiles, fw);

marshal technique accepts:

java.Io.OutputStream

java.Io.Writer

javax.Xml.Trform.Result

associated with XSLT

org.W3c.Dom.Node

associated with DOM

 org.Xml.Sax.ContentHandler

related to SAX

• Other Marshaller techniques

boolean setEventHandler(ValidationEventHandler handler)

equal as use with Unmarshaller, however validation events

are brought for the duration of marshalling

void setProperty(String name, Object cost)

supported houses are

jaxb.Encoding – cost is a String

the encoding to use while marshalling; defaults to “UTF-eight”

jaxb.Formatted.Output – value is a Boolean

actual to output line breaks and indentation; fake to omit (the default)

jaxb.SchemaLocation – fee is a String

to specify xsi:schemaLocation attribute in generated XML

jaxb.NoNamespaceSchemaLocation – price is a String

to specify xsi:noNamespaceSchemaLocation attribute in generated XML

Q12. How To Unmarshall Xml Into Java Objects? Convert From Xml To Java Objects?

Example:

ObjectFactory manufacturing facility = new ObjectFactory();

Unmarshaller u = factory.CreateUnmarshaller();

Cars vehicles = (Cars) u.Unmarshal(new FileInputStream(“vehicles.Xml”));

unmarshal approach accepts:

java.Io.File

java.Io.InputStream

java.Net.URL

javax.Xml.Trform.Source

related to XSLT:

org.W3c.Dom.Node

related to DOM:

org.Xml.Sax.InputSource

associated with SAX:

• Other Unmarshaller techniques

 void setValidating(boolean validating)

• real to enable validation at some stage in unmarshalling; false to disable (the default)

  boolean setEventHandler(ValidationEventHandler handler)

• handleEvent technique of ValidationEventHandler is known as

  if validation errors are encountered at some point of unmarshalling

• default handler terminates marshalling after first blunders

• return authentic to retain unmarshalling

• return false to terminate with UnmarshalExceptio

• see dialogue of ValidationEventCollector later

Q13. Explain Jaxb Use Cases?

Create/Read/Modify XML using Java

however with out the use of SAX or DOM

Validate person input:

the use of rules described in XML Schemas

Use XML-primarily based configuration files

get entry to their values

write tools that creates and modifies these documents

Q14. What Is Xml Binding?

Maps XML to in-reminiscence gadgets in step with a schema

Generates classes to represent XML factors:

so builders don’t ought to write them

the “binding compiler” does this

the training follow JavaBe assets get right of entry to conventions

Supports 3 number one operations:

marshalling a tree of gadgets into an XML report

unmarshalling an XML file right into a tree of objects

consists of validation of the XML towards the schema:

used to generate the instructions of the gadgets validation of item trees against the schema used to generate their training

a few constraints are enforced at the same time as working with the objects

others are only enforced whilst validation is requested

Q15. How To Generate Java From Xml Schema. Please Show The Example?

From command-line:

Windows: %JAXB_HOMEpercentbinxjc automobiles.Xsd

UNIX: %JAXB_HOME%/bin/xjc.Sh automobiles.Xsd

those write generated documents to current directory

From Ant:

 <java jar="$env.JAXB_HOME/lib/jaxb-xjc.Jar" fork="yes">

<arg line="-d $gen.Src.Dir cars.Xsd"/>

</java>

Generated Files:

• com/withoutbook/cars directory

Car.Java:

interface representing the “vehicle” complicated type

only describes get and set strategies for vehicle homes

Cars.Java:

interface representing “cars” international detail

extends CarsType and javax.Xml.Bind.Element (only a marker interface)

describes no additional methods

CarsType.Java:

interface representing nameless complex type described inside the “automobiles” global detail

offers approach to get series of Car gadgets (as a java.Util.List)

ObjectFactory.Java:

class used to create gadgets of the above interface sorts

extends DefaultJAXBContextImpl which extends JAXBContext

bgm.Ser:

a serialized item of kind com.Sun.Msv.Grammar.Trex.TREXGrammar

can’t locate any documentation in this - don’t recognise its cause

jaxb.Residences:

units a property that defines the magnificence used to create JAXBContext gadgets

com/withoutbook/cars/impl listing

CarImpl.Java:

magnificence that implements Car

corresponds to the “automobile” XML Schema complexType

CarsTypeImpl.Java:

magnificence that implements CarType

corresponds to the XML Schema anonymous kind in the “automobiles” detail

CarsImpl.Java:

elegance that extends CarsTypeImpl and implements Cars

corresponds to the “cars” XML Schema element 

Q16. Explain Customizing Type Bindings?

Default bindings may be overridden:

at international scope

on case-via-case basis

Customizations include

names of generated package, instructions and techniques

approach return sorts

elegance property (field) kinds

which elements are bound to lessons, in place of being omitted

elegance belongings to which every characteristic and detail statement is sure

Q17. What Is The Syntax Of Schemabindings?

The syntax for the schemaBindings detail is

<jxb:schemaBindings>

<jxb:package [name="package-name"]>

<jxb:javadoc> ... Javadoc ... </jxb:javadoc>

</package>

<jxb:nameXmlTrform>

<jxb:typeName prefix="prefix" suffix="suffix"/>

<jxb:elementName prefix="prefix" suffix="suffix"/>

<jxb:modelGroupName prefix="prefix" suffix="suffix"/>

<jxb:anonymousTypeName prefix="prefix" suffix="suffix"/>

</jxb:nameXmlTrform>

</jxb:schemaBindings>

– each detail and attribute inside schemaBindings is non-obligatory

Q18. Discuss Global Bindings Attributes?

CollectionType:

“listed” (uses array and gives methods to get/set elements) or absolutely-qualified-java-elegance-name(have to put in force java.Util.List)

default is “java.Util.ArrayList”

enableFailFastCheck:

"genuine” or “fake” (default)

if proper, invalid assets values are said as quickly as they are set, as opposed to ready till validation is requested

no longer carried out but in RI

generateIsSetMethod:

“authentic” or “false” (default)

if authentic, generates isSet and unSet strategies for the assets

underscoreBinding

“asCharInWord” or “asWordSeparator” (default)

if “asWordSeparator” , underscores in XML names are eliminated and words are camel-cased to form Java call

for example, “gear_shift_knob” goes to “gearShiftKnob”

bindingStyle (was modelGroupAsClass):

“modelGroupBinding” or “elementBinding” (default)

choiceContentProperty:

“true” or “fake” (default)

lets in gadgets to maintain one in all some of belongings alternatives which may also each have a specific records type

enableJavaNamingConventions:

“genuine” (default) or “false”

fixedAttributeAsConstantProperty:

“true” or “fake” (default)

if authentic, “constant” attributes will be represented as constants

typesafeEnumBase:

“xsd:string” , “xsd:decimal” , “xsd:float” , “xsd:double” or “xsd:NCName” (default)

defines field kind used to represent enumerated values in generated typesafe enum class

typesafeEnumMemberName:

“generateName” or “generateError” (default)

specifies what to do if an enumerated fee can not be mapped to a valid Java identifier

“generateName” generates names within the form VALUE_#

“generateError” reviews an mistakes