标签:
We‘ll stick with the tradition and use a sort of "Hello World" XML document to illustrate the typical scenario for creating the Java classes and their use to marshal a document. We‘ll not discuss any details in this subsection; it‘s just here to give you the overall picture.
The XML Schema on hello.xsd
defines the structure of our document, which is to contain a series of salutations, each of which contains a greeting (such as "Hello world") and an attribute for registering the language of the salutation.
<?xml version="1.0" encoding="UTF-8"?> <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:jxb="http://java.sun.com/xml/ns/jaxb" jxb:version="2.0"> <xsd:element name="Greetings" type="GreetingListType"/> <xsd:complexType name="GreetingListType"> <xsd:sequence> <xsd:element name="Greeting" type="GreetingType" maxOccurs="unbounded"/> </xsd:sequence> </xsd:complexType> <xsd:complexType name="GreetingType"> <xsd:sequence> <xsd:element name="Text" type="xsd:string"/> </xsd:sequence> <xsd:attribute name="language" type="xsd:language"/> </xsd:complexType> </xsd:schema>
Now we can call the JAXB schema compiler, defining the package name hello
for the generated classes.
xjc -p hello hello.xsd
This generates several classes in the subdirectory hello
. The class Hello
shows how to use them.
import java.util.*; import javax.xml.bind.*; import hello.*; public class Hello { private ObjectFactory of; private GreetingListType grList; public Hello(){ of = new ObjectFactory(); grList = of.createGreetingListType(); } public void make( String t, String l ){ GreetingType g = of.createGreetingType(); g.setText( t ); g.setLanguage( l ); grList.getGreeting().add( g ); } public void marshal() { try { JAXBElement<GreetingListType> gl = of.createGreetings( grList ); JAXBContext jc = JAXBContext.newInstance( "hello" ); Marshaller m = jc.createMarshaller(); m.marshal( gl, System.out ); } catch( JAXBException jbe ){ // ... } } }
The constructor uses a method from the object factory to create an object of the document‘s top level XML element type, i.e., GreetingListType
. The make
method adds another salutation with its text element and the language attribute. Finally, with a call to marshal
, the list is wrapped in its XML element, and the resulting XML document is written to the standard output stream. Here‘s a sequence of these calls:
Hello h = new Hello(); h.make( "Bonjour, madame", "fr" ); h.make( "Hey, you", "en" ); h.marshal();
The output is shown below, formatted, for better readability.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <Greetings> <Greeting language="fr"> <Text>Bonjour, madame</Text> </Greeting> <Greeting language="en"> <Text>Hey, you</Text> </Greeting> </Greetings>
标签:
原文地址:http://www.cnblogs.com/huey/p/5504182.html