Jaxb-annotations, top-level elements:xmlrootelement

A class that describes an XML element, a top-level element, i.e., one of the can function as an XML document, s Hould is annotated with XmlRootElement . Its optional elements is name and namespace . By default, the class name is used as the name.

This annotation corresponds to a xsd:element construct being used at the outermost level of a XML schema. The sequence of Java, XML and schema snippets given below illustrates this relation.

@XmlRootElement (name= "Doc" )publicclass  Document {   @XmlElement     protected  foo foo;    //  ...}

<? XML version= "1.0" encoding= "UTF-8" ?> < Doc >    < Foo >... </ Foo > </ Doc >

<?XML version= "1.0" encoding= "UTF-8"?><Xsd:complextypename= "Foo">    ...</Xsd:complextype><Xsd:complextypename= "Document">    <xsd:sequence>        <xsd:elementname= "Foo"type= "Foo"/>    </xsd:sequence></Xsd:complextype><xsd:elementname= "Doc"type= "Document"/>

It's a surprising fact so if all of the your Java classes permit a straightforward mapping to XML Schema, could be the XmlRootElement O nly annotation You has to make! Here's a small set of classes, that's even capable of marshalling a Map<K,V> .

ImportJava.util.HashMap;ImportJava.util.Map;Importjavax.xml.bind.annotation.*; @XmlRootElement (name= "Doc") Public classDocType { PublicMap<keytype,entrytype> Key2entry =NewHashmap<keytype,entrytype>();  PublicDocType () {}}ImportJavax.xml.datatype.*; Public classKeyType { PublicString event;  PublicXmlgregoriancalendar datetime;  PublicKeyType () {} PublicKeyType (String event, Xmlgregoriancalendar datetime) { This. event =event;  This. DateTime =datetime; }} Public classEntryType { PublicString Program;  PublicString Artists;  Publicentrytype () {} Publicentrytype (String artists, string program) { This. Artists =artists;  This. program =Program ; }}

Applying the usual incantations for creating and marshalling content, your could produce XML data like so:

<Doc>    <Key2entry>        <entry>            <Key>                <Event>Soiree</Event>                <datetime>2008-08-23t20:00:00</datetime>            </Key>            <value>                < Program>Mans on the Moon</ Program>                <Artists>R.e.m</Artists>            </value>        </entry>    </Key2entry></Doc>

XMLGregorianCalendar xsd:dateTime The is mapped to, and the ' between the date and the time T are just right, according to the Schema Datatyp ES specification. You can see this JAXB had to "invent" a few tag names for the intermediary element levels separating map entries from each Other, and key data from the value data, but you ' d has to does something similar if you ' d design it yourself.

Jaxb-annotations, top-level elements:xmlrootelement