CODEWITHSUNDEEP
javaxmljaxb
andrucz
andrucz

Reputation: 2021

Dynamic XML tags and JAXB

How can I use JAXB to serialize and deserialize the following XML, considering that tags complement1, 2 and 3 are not required and XML might have complement4, 5, n?

I thought about using @XmlAnyElement annotation, but I need to know that the value "First" belongs to the first complement, "Second" to the second, etc.

<resource>
    <id>Identifier</id>
    <name>Name</name>
    <complement1>First</complement1>
    <complement2>Second</complement2>
    <complement3>Third</complement3>
</resource>

Upvotes: 4

Views: 2848

Answers (1)

davidfrancis
davidfrancis

Reputation: 3849

I believe you can use @XmlAnyElement, and you do have access to the element name.
You need to use a "List of any" construct.
When JAXB unmarshalls the XML you will have a list of DOM Element objects, each of which contains the element name and contents.
I think you'd have to manually enforce that each element tag name matched the "complementN" pattern.

e.g. this is modified from one of the Oracle samples:

Schema:

<xs:element name="person">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="firstname" type="xs:string"/>
      <xs:element name="lastname" type="xs:string"/>
      <xs:sequence>
          <xs:any minOccurs="0" maxOccurs="unbounded"/>
      </xs:sequence>
    </xs:sequence>
  </xs:complexType>
</xs:element>

Snippet from xjc generated Person class:

...
@XmlRootElement(name = "person")
public class Person {

    @XmlElement(required = true)
    protected String firstname;
    @XmlElement(required = true)
    protected String lastname;
    @XmlAnyElement(lax = true)
    protected List<Object> any;
...

Test XML file:

<?xml version="1.0" encoding="utf-8"?>
<person>
  <firstname>David</firstname>
  <lastname>Francis</lastname>
  <anyItem1>anyItem1Value</anyItem1>
  <anyItem2>anyItem2Value</anyItem2>
</person>

Test class:

JAXBContext jc = JAXBContext.newInstance( "generated" );
Unmarshaller u = jc.createUnmarshaller();
Person contents = (Person) u.unmarshal(Testit.class.getResource("./anysample_test1.xml"));
System.out.println("contents: " + contents);
System.out.println("  firstname: " + contents.getFirstname());
System.out.println("  lastname: " + contents.getLastname());
System.out.println("  any: ");
for (Object anyItem : contents.getAny()) {
    System.out.println("    any item: " + anyItem);
    Element ele = (Element) anyItem;
    System.out.println("      ele name: " + ele.getTagName());
    System.out.println("      ele text content: " + ele.getTextContent());
}

Output:

contents: generated.Person@1bfc93a
  firstname: David
  lastname: Francis
  any: 
    any item: [anyItem1: null]
      ele name: anyItem1
      ele text content: anyItem1Value
    any item: [anyItem2: null]
      ele name: anyItem2
      ele text content: anyItem2Value

Upvotes: 6

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