Using JAXB

1
Using JAXB

• Revisited

2
An XSDL Document for an ItemList

• lt?xml version"1.0" encoding"utf-8"?gt
• ltxsdschema xmlnsxsd'http//www.w3.org/2001/XMLS
  chema'gt
• ltxsdelement name"itemList"gt
• ltxsdcomplexTypegt
• ltxsdsequencegt
• ltxsdelement ref"item"
• minOccurs"0"
  maxOccurs"3"/gt
• lt/xsdsequencegt
• lt/xsdcomplexTypegt
• lt/xsdelementgt

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ltxsdelement name"item"gt ltxsdcomplexTypegt
ltxsdsequencegt ltxsdelement
ref"name"/gt ltxsdelement
ref"quantity"/gt lt/xsdsequencegt
lt/xsdcomplexTypegt lt/xsdelementgt ltxsdelement
name"name" type"xsdstring"/gt ltxsdelement
name"quantity" type"xsdshort"/gt lt/xsdschemagt
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A Document Instance

• lt?xml version"1.0" encoding"utf-8"?gt
• ltitemList
• xmlnsxsi'http//www.w3.org/2001/XMLSchema-inst
  ance'
• xsinoNamespaceSchemaLocation"itemList.xsd"gt
• ltitemgt
• ltnamegtpenlt/namegt
• ltquantitygt5lt/quantitygt
• lt/itemgt
• ltitemgt
• ltnamegteraserlt/namegt
• ltquantitygt7lt/quantitygt
• lt/itemgt
• ltitemgt
• ltnamegtstaplerlt/namegt
• ltquantitygt2lt/quantitygt
• lt/itemgt
• lt/itemListgt

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An Ant Build file

• lt?xml version"1.0"?gt
• lt! adapted from Suns jaxb build file ?
• ltproject basedir"." default"run"gt
• ltpath id"classpath"gt
• ltfileset dir"D\jwsdp-1.2\jaxb\lib"
  includes".jar"/gt
• ltfileset dir"D\jwsdp-1.2\common\lib"
  includes".jar"/gt
• ltfileset dir"D\jwsdp-1.2\jaxp\lib\endors
  ed" includes".jar"/gt
• ltfileset dir"D\jwsdp-1.2\jwsdp-shared\li
  b" includes".jar"/gt
• ltfileset dir"D\jwsdp-1.2\jaxp\lib"
  includes".jar"/gt
• ltpathelement location"."/gt
• lt/pathgt

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lttaskdef name"xjc" classname"com.sun.tools.
xjc.XJCTask"gt ltclasspath
refid"classpath" /gt lt/taskdefgt lt!--
generate Java source files --gt lttarget
name"generate"gt lt!-- generate the
Java content classes from the schema --gt
ltecho message"Compiling the schema..."/gt
ltxjc schema"itemList.xsd" target"."
package"itemListAPI"/gt lt!-- generate
the javadocs from the content classes --gt
ltmkdir dir"docs/api"/gt ltjavadoc
packagenames"itemListAPI"
sourcepath"."
destdir"docs/api"
windowtitle"Generated Interfaces for
itemList.xsd"gt ltclasspath
refid"classpath" /gt lt/javadocgt
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lt!-- compile all of the java sources --gt
ltecho message"Compiling the java source
files..."/gt ltjavac srcdir"." destdir"."
debug"on"gt ltclasspath
refid"classpath" /gt lt/javacgt
lt/targetgt lttarget name"JustJava"gt
lt!-- compile all of the java sources --gt
ltecho message"Compiling the java source
files..."/gt ltjavac srcdir"." destdir"."
debug"on"gt ltclasspath
refid"classpath" /gt lt/javacgt
lt/targetgt
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lttarget name"JustJavaRun"gt ltecho
message"java runtime"/gt ltjava
classname"Main" fork"true"gt
ltclasspath refid"classpath" /gt lt/javagt
lt/targetgt lttarget name"run"
depends"generate"gt ltecho
message"Running the sample application..."/gt
ltjava classname"Main" fork"true"gt
ltclasspath refid"classpath" /gt
lt/javagt lt/targetgt lt/projectgt
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Running the build

• D\McCarthy\www\95-733\examples\struts1\src\VOgtant
  generate
• Buildfile build.xml
• generate
• echo Compiling the schema...
• xjc Compiling file/D/McCarthy/www/95-733
  /examples/struts1/src/VO/itemL
• ist.xsd
• xjc Writing output to D\McCarthy\www\95-7
  33\examples\struts1\src\VO
• javadoc Generating Javadoc
• javadoc Javadoc execution
• javadoc Loading source files for package
  itemListAPI...
• javadoc Constructing Javadoc information...
• javadoc Standard Doclet version 1.4.2
• javadoc Building tree for all the packages
  and classes...
• javadoc Building index for all the packages
  and classes...
• javadoc Building index for all classes...
• echo Compiling the java source files...
• javac Compiling 42 source files to
  D\McCarthy\www\95-733\examples\struts1
• \src\VO

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Viewing the docs
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Write the client

• import java.io.File
• import java.io.IOException
• import java.math.BigDecimal
• import javax.xml.bind.JAXBContext
• import javax.xml.bind.JAXBException
• import javax.xml.bind.Marshaller
• import javax.xml.bind.UnmarshalException
• import javax.xml.bind.Unmarshaller
• import javax.xml.bind.ValidationEvent
• import javax.xml.bind.util.ValidationEventCollecto
  r
• // import java content classes generated by
  binding compiler
• import itemListAPI.
• public class Main
• // This sample application demonstrates how
  to enable validation during

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public static void main( String args )
try // create a JAXBContext
capable of handling classes generated into
// the itemListAPI package
JAXBContext jc JAXBContext.newInstance(
"itemListAPI" ) //
create an Unmarshaller Unmarshaller u
jc.createUnmarshaller() // enable
validation u.setValidating( true )

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// in this example, we will allow the
Unmarshaller's default //
ValidationEventHandler to receive notification of
warnings // and errors which will be
sent to System.out. The default //
ValidationEventHandler will cause the unmarshal
operation // to fail with an
UnmarshalException after encountering the
// first error or fatal error.
// unmarshal an invalid itemList
instance document into a tree of Java
// content objects composed of classes from the
itemListAPI package. ItemList
itemList (ItemList)u.unmarshal(
new File( "itemList.xml" ) )
java.util.List list
itemList.getItem()
System.out.println("The length of the list is "
list.size())
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int n list.size()
for(int k 0 k lt n k)
ItemType it (ItemType)list.get(k)
String st it.getName()
System.out.println(st)
catch( UnmarshalException ue )
// The JAXB specification does not
mandate how the JAXB provider // must
behave when attempting to unmarshal invalid XML
data. In // those cases, the JAXB
provider is allowed to terminate the
// call to unmarshal with an UnmarshalException.
System.out.println( "Caught
UnmarshalException" ) catch(
JAXBException je )
je.printStackTrace()
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Running the Client

• D\McCarthy\www\95-733\examples\struts1\src\VOgtant
  JustJavaRun
• Buildfile build.xml
• JustJavaRun
• echo java runtime
• java The length of the list is 3
• java pen
• java eraser
• java stapler
• BUILD SUCCESSFUL
• Total time 2 seconds