Develop Reference

Unmarshal big xml files using JAXB

I have 1-2MB xml files and I would like to load them into the list of objects. I wanted to do it through JAXB because I have the appropriate XSD, only the problem appears when loading these files because it throws me errors saying that there is an unclosed tag somewhere, or something like that, when I check the file, there are no errors there. When I loaded files with a size of e.g. 40KB, there was no problem, everything was loading properly. So I understand there's a problem in jaxb when unmarshaling larger files. Is there any way to eat this? Another way of unmarshalling is unlikely to be included in the game because each xml file has a slightly different structure and objects that I have created with XSD.
The structure of xml files:
<Request>
<Header>
<Name> </Name>
<Id> </Id>
</Header>
<RequestItems>
<Request>
<Header>
<Name> </Name>
<Id> </Id>
</Header>
<ObjectName>
<City> </City>
<Street> </Street>
</ObjectName>
</Request>
</RequestItems>
</Request>
Inside the RequestItems tags there is a list of Request objects and in the Request ObjectName objects it is different depending on the file.
I do unmrashal in the simplest way and for smaller files it works fine, and the larger ones have strange syntax errors but I understand that it just cuts lines because it is too long and therefore there are syntactic errors.
JAXBContext jaxbContext = JAXBContext.newInstance (Request.class);
Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller ();
Request request = (Request) jaxbUnmarshaller.unmarshal (xmlFile);

If I have understood your question correctly then this should work. I have used Moxy which is an extension of Jaxb and Project Lombok for Getter setter.
Imagine the following is the large XML with different structures request.xml:
<request>
<person>
<name>Batman</name>
<age>29</age>
<job>IT</job>
</person>
<animal>
<name>Tommy</name>
<age>5</age>
<type>Dog</type>
</animal>
<person>
<name>Superman</name>
<age>30</age>
<job>HR</job>
</person>
</request>
Following are the related classes and interface:
import jakarta.xml.bind.annotation.XmlSeeAlso;
#XmlSeeAlso({Person.class, Animal.class})
public interface XmlSupportExtension {
Object xmlSupport();
}
import jakarta.xml.bind.annotation.XmlAccessType;
import jakarta.xml.bind.annotation.XmlAccessorType;
import jakarta.xml.bind.annotation.XmlTransient;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.io.Serializable;
#Data
#NoArgsConstructor
#AllArgsConstructor
#XmlAccessorType(XmlAccessType.FIELD)
#XmlTransient
public class Common implements Serializable {
private String name;
private String age;
}
import lombok.*;
#Data
#EqualsAndHashCode(callSuper = true)
#ToString(callSuper = true)
#NoArgsConstructor
#AllArgsConstructor
public class Person extends Common implements XmlSupportExtension {
private String job;
#Override
public Person xmlSupport() {
return this;
}
}
import lombok.*;
#Data
#EqualsAndHashCode(callSuper = true)
#ToString(callSuper = true)
#NoArgsConstructor
#AllArgsConstructor
public class Animal extends Common implements XmlSupportExtension {
private String type;
#Override
public Animal xmlSupport() {
return this;
}
}
import jakarta.xml.bind.JAXBContext;
import jakarta.xml.bind.JAXBException;
import jakarta.xml.bind.Unmarshaller;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.Arrays;
public class MainStack {
public static void main(String[] args) throws JAXBException, XMLStreamException, FileNotFoundException {
final String[] EVENT_TYPES = new String[]{"person", "animal"};
InputStream inputStream = MainStack.class.getResourceAsStream("/request.xml");
//Create an instance of XMLStreamReader to read the events one-by-one
final XMLInputFactory inputFactory = XMLInputFactory.newInstance();
inputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, Boolean.FALSE);
inputFactory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, Boolean.FALSE);
final XMLStreamReader xmlStreamReader = inputFactory.createXMLStreamReader(inputStream);
//Create an instance of JAXBContext and Unmarshaller for unmarshalling the classes to respective event
final Unmarshaller unmarshaller = JAXBContext.newInstance(Person.class, Animal.class).createUnmarshaller();
//Navigate to next and start of the XML Elements
xmlStreamReader.next();
//Read Until the end of the file and unmarshall event-by-event
while (xmlStreamReader.hasNext()) {
//Check if the initial element is one of the elements from "EVENT_TYPES"
if (xmlStreamReader.isStartElement() && Arrays.asList(EVENT_TYPES).contains(xmlStreamReader.getLocalName())) {
//Get the event type
final String eventType = xmlStreamReader.getLocalName();
Object event = null;
System.out.println(eventType);
// Based on eventType make unmarshaller call to respective event class
switch (eventType) {
case "person":
//Unmarshal the Person
event = unmarshaller.unmarshal(xmlStreamReader, Person.class).getValue();
break;
case "animal":
//Unmarshal the Animal
event = unmarshaller.unmarshal(xmlStreamReader, Animal.class).getValue();
break;
default:
//If NONE of the event type matches then do not convert and make a note
System.out.println("XML event does not match any of the required event : " + event);
break;
}
System.out.println(" After Unmarhsalling : " + event.toString());
}
//Move to the next event/element in InputStream
xmlStreamReader.next();
}
}
}
This will produce the following output:
person
After Unmarhsalling : Person(super=Common(name=Batman, age=29), job=IT)
animal
After Unmarhsalling : Animal(super=Common(name=Tommy, age=5), type=Dog)

JAXB-Return the entire XML object even if i don't have values

I'm trying to return an xml response with JAXB and the implementation looks like in the example bellow. My question is: There is a way to return the whole xml without setting a value on the field?
#ResponsePayload
public JAXBElement<Ns2AnfrageBonitaetsauskunftAntwortType> getResponse(#RequestPayload JAXBElement<Ns2AnfrageBonitaetsauskunftTyp> request) {
Ns2AnfrageBonitaetsauskunftAntwortType response = new Ns2AnfrageBonitaetsauskunftAntwortType();
response.setSchufaReferenz("test2");
response.setTeilnehmerreferenz("test1");
response.setAktionsdaten("test3");
Ns3BonitaetsauskunftType bonita = new Ns3BonitaetsauskunftType();
bonita.setTeilnehmerkennung("test4");
Ns3VerarbeitungsinformationType verar = new Ns3VerarbeitungsinformationType();
verar.setErgebnistyp("test7");
bonita.setVerarbeitungsinformation(verar);
Ns3VerbraucherdatenAuskunftType daten = new Ns3VerbraucherdatenAuskunftType();
daten.setPersonOhneGeburtsdatum("test6");
bonita.setVerbraucherdaten(daten);
response.setReaktion(bonita);
ObjectFactory objectFactory = new ObjectFactory();
return objectFactory.createBonitaetsauskunft(response);
}
At the moment the response look like this:
<env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope">
<env:Header/>
<env:Body>
<ns3:Bonitaetsauskunft xmlns:ns3="http://ifd-schema.de/BonitaetsauskunftSCHUFA">
<SchufaReferenz>test2</SchufaReferenz>
<Teilnehmerreferenz>test1</Teilnehmerreferenz>
<Aktionsdaten xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">test3</Aktionsdaten>
<Reaktion>
<Teilnehmerkennung>test4</Teilnehmerkennung>
<Verbraucherdaten>
<PersonOhneGeburtsdatum>test6</PersonOhneGeburtsdatum>
</Verbraucherdaten>
<Verarbeitungsinformation>
<Ergebnistyp>test7</Ergebnistyp>
</Verarbeitungsinformation>
</Reaktion>
</ns3:Bonitaetsauskunft>
</env:Body>
</env:Envelope>
I have a lot of more field on which i don't want to set a value but i want them to be in the response. Any ideas?
Thank you

You can add to each property nillable attribut using #XmlElement(nillable = true) annotation. From documentation:
Optional. Specifies whether an explicit null value can be assigned to
the element. True enables an instance of the element to have the null
attribute set to true. The null attribute is defined as part of the
XML Schema namespace for instances. Default is false
Fields with this attribute are print as <value xsi:nil="true"/>. Small example:
import javax.xml.XMLConstants;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
public class JaxbApp {
public static void main(String[] args) throws Exception {
Root dataFile = new Root();
dataFile.setPerson(new Person());
JAXBContext jaxbContext = JAXBContext.newInstance(Root.class);
Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.setProperty(Marshaller.JAXB_SCHEMA_LOCATION, XMLConstants.W3C_XML_SCHEMA_INSTANCE_NS_URI);
marshaller.marshal(dataFile, System.out);
}
}
#XmlRootElement(name = "roo")
#XmlAccessorType(XmlAccessType.FIELD)
class Root {
#XmlElement(nillable = true)
private Integer id;
#XmlElement(nillable = true)
private String value;
#XmlElement(nillable = true)
private Person person;
// getters, setters, toString
}
#XmlAccessorType(XmlAccessType.FIELD)
class Person {
#XmlElement(nillable = true)
private String name;
#XmlElement(nillable = true)
private String lastName;
// getters, setters, toString
}
prints:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<roo xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.w3.org/2001/XMLSchema-instance">
<id xsi:nil="true"/>
<value xsi:nil="true"/>
<person>
<name xsi:nil="true"/>
<lastName xsi:nil="true"/>
</person>
</roo>
In that case you need to change your XSD/WSDL document and add this attribute to each primitive field. Of course, you still need to create new POJO instance like new Person() in above example. You can of course set each property in class to some kind of default value private String value = ""; or write reflection tool which travers all properties and set to some custom values.
See also:
Represent null value as empty element in xml jaxb

EclipseLink Moxy unmarshall Collection with different Element names

I have a class which contains an ArrayList(SuperClass) property. Now I wish to unmarshall the following XML file which contains different element names in that collection because these are subclasses of the Superclass. Is there a way of doing this with Moxy?
<?xml version="1.0" encoding="UTF-8"?>
<SmMessageSet xmlns:nav="urn:ccsds:recommendation:navigation:schema:ndmxml:R1.5"
xmlns="urn:ccsds:recommendation:service_management:schema:sccs:R1.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ccsds:recommendation:service_management:schema:sccs:R1.0 file:/C:/CCSDS-910.11-B-1_XML_schemas/CCSDS-910.11-B-1_XML_schemas/SmSchema-v1.0.0.xsd">
<sccsSmVersionRef>sccsSmVersionRef0</sccsSmVersionRef>
<smSource>smSource0</smSource>
<smDestination>smDestination0</smDestination>
<serviceAgreementRef>serviceAgreementRef0</serviceAgreementRef>
<smMessages>
<querySpaceCommunicationServiceProfileFailedReturn>
<messageSequenceNumber>50</messageSequenceNumber>
<messageTimestamp>2006-05-04T18:13:51.0</messageTimestamp>
<invocationMessageSequenceNumber>50</invocationMessageSequenceNumber>
<spaceCommunicationServiceProfileRef>spaceCommunicationServiceProfileRef0
</spaceCommunicationServiceProfileRef>
<qscspError>
<erroredItem>erroredItem0</erroredItem>
<diagnostic>operation timeout</diagnostic>
</qscspError>
<qscspError>
<erroredItem>erroredItem1</erroredItem>
<diagnostic>operation timeout</diagnostic>
</qscspError>
</querySpaceCommunicationServiceProfileFailedReturn>
<createUserAccountInvocation1>
<messageSequenceNumber>50</messageSequenceNumber>
<messageTimestamp>2006-05-04T18:13:51.0</messageTimestamp>
<username>createdUser</username>
<password>createdPassword</password>
<firstname>Test</firstname>
<lastname>User</lastname>
<email>test.user#host.de</email>
<role>SCHEDULING_OFFICER</role>
<superuser>0</superuser>
</createUserAccountInvocation1>
</smMessages>
</SmMessageSet>
The querySpaceCommunicationServiceProfileFailedReturn and createUserAccountInvocation are in my java object model subclasses of SmMessage base class, which is held by the SmMessageSet class in an, as above described, ArrayList of SmMessage classes.
I would also like to not change the current XML structure (i.e. create a wrapper element around the SmMessages in the XML file).
Any help would be appreciated :)

You could do the following leveraging #XmlElementWrapper and #XmlElementRef:
Java Model
SmMessageSet
You can use the #XmlElementWrapper annotation to add a grouping element around the collection (see: http://blog.bdoughan.com/2010/09/jaxb-collection-properties.html). You can also use the #XmlElementRef annotation to model the element name as the inheritance indicator (substitution groups in XML Schema, see: http://blog.bdoughan.com/2010/11/jaxb-and-inheritance-using-substitution.html).
package forum20745762;
import java.util.List;
import javax.xml.bind.annotation.*;
#XmlRootElement(name="SmMessageSet")
#XmlAccessorType(XmlAccessType.FIELD)
public class SmMessageSet {
#XmlElementWrapper
#XmlElementRef
private List<SmMessage> smMessages;
}
SmMessage
JAXB/MOXy won't automatically pull in all subclasses of a class, so you can use the #XmlSeeAlso annotation to have them pulled in.
package forum20745762;
import javax.xml.bind.annotation.XmlSeeAlso;
#XmlSeeAlso({CreateUserAccountInvocation.class, QuerySpaceCommunicationServiceProfileFailedReturn1.class})
public class SmMessage {
}
CreateUserAccountInvocation
One each of the subclasses you need to annotate with #XmlRootElement. This is the element name that the #XmlElementRef annotation will match on.
package forum20745762;
import javax.xml.bind.annotation.XmlRootElement;
#XmlRootElement
public class CreateUserAccountInvocation extends SmMessage {
}
QuerySpaceCommunicationServiceProfileFailedReturn1
package forum20745762;
import javax.xml.bind.annotation.XmlRootElement;
#XmlRootElement
public class QuerySpaceCommunicationServiceProfileFailedReturn1 extends SmMessage {
}
package-info
We will use the package level #XmlSchema annotation to map the namespaces (see: http://blog.bdoughan.com/2010/08/jaxb-namespaces.html).
#XmlSchema(
namespace="urn:ccsds:recommendation:service_management:schema:sccs:R1.0",
elementFormDefault=XmlNsForm.QUALIFIED
)
package forum20745762;
import javax.xml.bind.annotation.*;
Demo Code
Demo
The following demo code will read the XML from your question, and then write it back out.
package forum20745762;
import java.io.File;
import javax.xml.bind.*;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(SmMessageSet.class);
Unmarshaller unmarshaller = jc.createUnmarshaller();
File xml = new File("src/forum20745762/input.xml");
SmMessageSet smMessageSet = (SmMessageSet) unmarshaller.unmarshal(xml);
Marshaller marshaller = jc.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.marshal(smMessageSet, System.out);
}
}
Output
The output below corresponds to just the subset of your XML document that I had mapped to:
<?xml version="1.0" encoding="UTF-8"?>
<SmMessageSet xmlns="urn:ccsds:recommendation:service_management:schema:sccs:R1.0">
<smMessages>
<querySpaceCommunicationServiceProfileFailedReturn1/>
<createUserAccountInvocation/>
</smMessages>
</SmMessageSet>

Using JAXB&MOXy to convert JPA entities to XML and back again

I am stuck with (I guess) a pretty trivial problem considering MOXy. Converting a class like this example (pastebin) to XML is no problem, converting it back goes without any errors too. Though, fields that are referencing another (or more) Person, will result in a null value.
Is there any way to make this work without losing relationships? My guess is this is due to a reference by ID only, since JAXB has no way of knowing other existing objects. I have tried using #XmlInverseReference, though this resulted in an infinite loop on every try.

EclipseLink MOXy's #XmlInverseReference is used to solve the infinite loop problem. I will demonstrate below with an example based on your model:
Person
package forum15821738;
import java.io.Serializable;
import java.util.List;
import javax.xml.bind.annotation.*;
import org.eclipse.persistence.oxm.annotations.XmlInverseReference;
#XmlRootElement
#XmlAccessorType(XmlAccessType.FIELD)
public class Person implements Serializable {
private String name;
#XmlInverseReference(mappedBy="children")
private Person parent;
#XmlElementWrapper
#XmlElement(name="child")
private List<Person> children;
public Person getParent() {
return parent;
}
public List<Person> getChildren() {
return children;
}
// OTHER GETTERS AND SETTERS
}
jaxb.properties
To specify MOXy as your JAXB provider you need to include a file called jaxb.properties in the same package as your domain model with the following entry (see: http://blog.bdoughan.com/2011/05/specifying-eclipselink-moxy-as-your.html)
javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory
Demo
package forum15821738;
import java.io.File;
import javax.xml.bind.*;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(Person.class);
Unmarshaller unmarshaller = jc.createUnmarshaller();
File xml = new File("src/forum15821738/input.xml");
Person person = (Person) unmarshaller.unmarshal(xml);
for(Person child : person.getChildren()) {
System.out.println(child.getParent());
}
Marshaller marshaller = jc.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.marshal(person, System.out);
}
}
Input/Output
forum15821738.Person#5893a012
forum15821738.Person#5893a012
<?xml version="1.0" encoding="UTF-8"?>
<person>
<name>Jane</name>
<children>
<child>
<name>Bobbie</name>
</child>
<child>
<name>Sue</name>
</child>
</children>
</person>
For More Information
http://blog.bdoughan.com/2010/07/jpa-entities-to-xml-bidirectional.html
http://blog.bdoughan.com/2013/03/moxys-xmlinversereference-is-now-truly.html

Serialize a Java Object

Let me know the best way to serialize my Java object Download. This is a class generated from a java wsimport tool from a WSDL.
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "Download", propOrder = {
"Response",
"VendorInformation",
"DownloadItem",
"DownloadCommentItem",
"DownloadIntercomItem"
})
public class Download
{
#XmlElement(name = "Response")
protected ResponseMessageManagementType Response;
#XmlElement(name = "VendorInformation")
protected DownloadVendorInformation VendorInformation;
#XmlElement(name = "DownloadItem")
protected List<DownloadDownloadItem> DownloadItem;
#XmlElement(name = "DownloadCommentItem")
protected ArrayOfDownloadDldComment DownloadCommentItem;
#XmlElement(name = "DownloadIntercomItem")
protected ArrayOfDownloadDldIntercom DownloadIntercomItem;
.........................
}
The java classes generated from the tool do not have any serlization implementation.
And I want to serialize the Download class following this kind of format:
<?xml version="1.0" encoding="utf-8"?>
<Download xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="HTTP://xyz.abc.Com//Vendor/DownloadWSE.xsd">
<Response>
.....
</Response>
<VendorInformation>
...............
</VendorInformation>
<DownloadItem>
<DownloadDownloadItem>
.......
</DownloadDownloadItem>
<DownloadDownloadItem>
.......
</DownloadDownloadItem>
<DownloadDownloadItem>
.......
</DownloadDownloadItem>
</DownloadItem>
<DownloadCommentItem>
........
</DownloadCommentItem>
<DownloadIntercomItem>
........
</DownloadIntercomItem>
</Download>
You can see the mapping between XmlElementName and the content of the XML string.
I am at loss on how to do this.
Thanks

This is JAXB. You would need:
JAXBContext ctx = JAXBConetxt.newInstance(Download.class);
Marshaller m = ctx.createMarshaller();
m.marshal(downloadObject, out);
where out can be lots of things, including OutputStream, Writer and File. If you want to get it as a String, use a StringWriter

This is JAXB, and to get your example working you need to supply root element and namespace information:
Root Element
When you marshal an object with JAXB it requires information about the root element. One way to do this is to annotate your Download class with #XmlRootElement
#XmlRootElement(name="Download")
public class Download
If you cannot do that you will need to wrap your instance of Download in a JAXBElement:
Download download = new Download();
QName qname = new QName("HTTP://xyz.abc.Com//Vendor/DownloadWSE.xsd";
JAXBElement<Download> jaxbElement = new JAXBElement(qname, "Download"), Download.class, download);
Namespace Qualification
Also to get the namespace qualification you are after you can use the package level #XmlSchema annotation:
#XmlSchema(
namespace="HTTP://xyz.abc.Com//Vendor/DownloadWSE.xsd",
elementFormDefault=XmlNsForm.QUALIFIED)
package your.model.package.containing.download;
import javax.xml.bind.annotation.*;
Demo
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.Marshaller;
import javax.xml.namespace.QName;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(Download.class);
Download download = new Download();
QName qname = new QName("HTTP://xyz.abc.Com//Vendor/DownloadWSE.xsd";
JAXBElement<Download> jaxbElement = new JAXBElement(qname, "Download"), Download.class, download);
Marshaller marshaller = jc.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.marshal(jaxbElement, System.out);
}
}