CODEWITHSUNDEEP
javaxmljaxb
Chris
Chris

Reputation: 41

JAXB unmarshalling xml both @XmlValue and @XmlElement

Hi I am unmarshalling a XML file that has a tag that can contain both a value or a list of elements. I was wondering what the best approach is for unmarshalling this kind of XML. Example:

<attributes>
    <attribute>value1</attribute>
    <attribute>value2</attribute>
    <attribute>value3</attribute>
    <attribute>value4</attribute>
    <attribute>
        <value>value11</value>
        <value>value12</value>
        <value>value13</value>
        <value>value14</value>
        <value>value15</value>
    </attribute>
    <attribute>value5</attribute>
    <attribute>value6</attribute>
</attributes>

I can't change the way of how the XML is build up so I am hoping someone has a answer. Thank you.

Upvotes: 2

Views: 605

Answers (1)

Jordi Castilla
Jordi Castilla

Reputation: 26961

Basic steps to read-write xml using JaxB / Unmarshaller and XSD

  • Create a valid XSD file of your XML structure. Find here an online generator.

    Will be something like this (but maybe you need to modify manually some detail, in your XML structure seems you can create the Attribute class wrapping several <attribute> but I dont know for sure if you can have more than one <attributes> tag):

    <xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="attributes">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="attribute" maxOccurs="unbounded" minOccurs="0">
          <xs:complexType mixed="true">
            <xs:sequence>
              <xs:element type="xs:string" name="value" maxOccurs="unbounded" minOccurs="0"/>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

  • Place it in your project folder.

  • Right click XSD file and auto-generate JAXB classes.

  • Use Unmarshaller to populate auto-generated classes from XML file:

    Unmarshaller u = jc.createUnmarshaller();
Attributes attributes = (Attributes) u.unmarshal( new FileInputStream( "yourFile.xml" ) );

That's it... JaxB will take care of classes, attributes, populate, write/read xml...

Upvotes: 2

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