In this section we'll show how to create XML from the beans generated earlier. XML (or better an XML document) exists in various flavours: you might want to have it serialized into a String or you may prefer character or byte streams (typically instances of Writer or OutputStream). In other cases, a DOM representation is more useful. Feeding SAX events to a pipeline may be more efficient on other occasions.
The important questions are: how do I create a serialized XML document (a String, a character or byte stream)? And, vice versa, how do I read such a document and convert it back into Java objects?
In the case of JaxMe, you'll start from simple Java beans whose source has typically been generated. An address implementation is constructed by instantiating an AddressImpl (which implements Address). For example:
import java.io.FileWriter; import java.io.Writer; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Marshaller; import org.apache.ws.jaxme.examples.misc.address.Address; import org.apache.ws.jaxme.examples.misc.address.AddressType.EmailDetailsType.EmailType; import org.apache.ws.jaxme.examples.misc.address.AddressType.PhoneDetailsType.PhoneType; import org.apache.ws.jaxme.examples.misc.address.impl.AddressImpl; import org.apache.ws.jaxme.examples.misc.address.impl.AddressTypeImpl.EmailDetailsTypeImpl; import org.apache.ws.jaxme.examples.misc.address.impl.AddressTypeImpl.EmailDetailsTypeImpl.EmailTypeImpl; import org.apache.ws.jaxme.examples.misc.address.impl.AddressTypeImpl.PhoneDetailsTypeImpl; import org.apache.ws.jaxme.examples.misc.address.impl.AddressTypeImpl.PhoneDetailsTypeImpl.PhoneTypeImpl; import org.apache.ws.jaxme.examples.misc.address.impl.AddressTypeImpl.NameTypeImpl; import org.apache.ws.jaxme.examples.misc.address.impl.AddressTypeImpl.PostalTypeImpl; public class AddressCreator { public static void writeAddress(Writer pWriter) throws JAXBException { // Create the element: Address addr = new AddressImpl(); addr.setName(new NameTypeImpl()); addr.getName().setFirst("Jane"); addr.getName().setLast("Doe"); addr.setPostal(new PostalTypeImpl()); addr.getPostal().setStreet("34 Main Street"); addr.getPostal().setCity("Boston"); addr.getPostal().setState("MA"); addr.getPostal().setZIP("02215"); addr.setEmailDetails(new EmailDetailsTypeImpl()); /* Lots of similar lines omitted for brevity ... * ... */ // And save it into the file "Address.xml" JAXBContext context = JAXBContext.newInstance("org.apache.ws.jaxme.examples.misc.address"); Marshaller marshaller = context.createMarshaller(); marshaller.marshal(addr, pWriter); } public static void main(String[] args) throws Exception { FileWriter fw = new FileWriter("Address.xml"); writeAddress(fw); fw.close(); } }The complete example code can be found in the JaxMe distribution (src/java/org/apache/ws/jaxme/examples/misc/address/AddressCreator.java).
There are several things you should note here:
The example on writing XML was surprisingly simple. In fact, the only nasty part was creating the object, which requires invocation of lots of setters and getters. Quite opposed to the marshalling, which took place in three lines. And, as we soon will see: unmarshalling (the process of reading a document) is by no means more complex.
To demonstrate the unmarshalling process, we'll quote an example from the JaxMe distribution again. This time it's the file src/java/org/apache/ws/jaxme/examples/misc/address/AddressPrinter.java:
package org.apache.ws.jaxme.examples.misc.address; import java.io.File; import java.io.FileInputStream; import java.io.StringWriter; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Marshaller; import javax.xml.bind.Unmarshaller; import org.apache.ws.jaxme.examples.misc.address.Address; import org.xml.sax.InputSource; public class AddressPrinter { public static Address getAddress(InputSource pSource) throws JAXBException { JAXBContext context = JAXBContext.newInstance("org.apache.ws.jaxme.examples.misc.address"); Unmarshaller unmarshaller = context.createUnmarshaller(); return (Address) unmarshaller.unmarshal(pSource); } public static String getAddressAsString(Address pAddress) throws JAXBException { StringWriter sw = new StringWriter(); JAXBContext context = JAXBContext.newInstance("org.apache.ws.jaxme.examples.misc.address"); Marshaller marshaller = context.createMarshaller(); marshaller.marshal(pAddress, sw); return sw.toString(); } public static void main(String[] args) throws Exception { File f = new File("Address.xml"); InputSource isource = new InputSource(new FileInputStream(f)); isource.setSystemId(f.toURL().toString()); Address addr = getAddress(isource); // A simpler variant might be: // Address addr = unmarshaller.unmarshal(f); if (addr.getName() == null) { System.out.println("Loaded address without name."); } else { System.out.println("Loaded address " + addr.getName().getLast() + ", " + addr.getName().getFirst() + "."); } System.out.println("Details:" + getAddressAsString(addr)); } }
How this example works: