Java example of JAXB @XmlRootElement annotation in detail along with its usage during marshalling and unmarshalling operations.
1. JAXB @XmlRootElement annotation type
@XmlRootElement maps a class or an enum type to an XML element. When a top level class or an enum type is annotated with the @XmlRootElement annotation, then its value is represented as XML element in an XML document.
@XmlRootElement annotation can be used with the following annotations: XmlType, XmlEnum, XmlAccessorType, XmlAccessorOrder.
1.1. Syntax
//Without name attribute @XmlRootElement //1 //With name attribute @XmlRootElement(name = "employee") //2
2. JAXB @XmlRootElement example
Now see few examples of how using @XmlRootElement changes the XML representations.
2.1. @XmlRootElement with ‘name’ attribute
@XmlRootElement(name = "employee")
@XmlAccessorType(XmlAccessType.FIELD)
public class EmployeeData implements Serializable {
private static final long serialVersionUID = 1L;
private Integer id;
private String firstName;
private String lastName;
}
Above converts to:
<employee>
<id>1</id>
<firstName>Lokesh</firstName>
<lastName>Gupta</lastName>
</employee>
2.2. @XmlRootElement without ‘name’ attribute
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class EmployeeData implements Serializable {
private static final long serialVersionUID = 1L;
private Integer id;
private String firstName;
private String lastName;
}
Above converts to:
<EmployeeData>
<id>1</id>
<firstName>Lokesh</firstName>
<lastName>Gupta</lastName>
</EmployeeData>
Drop me your questions in comments section.
Happy Learning !!
Reference : XmlRootElement Java Doc
Johnny
How to avoid root element? For example:
I have java classes Application and Person.
class Application { Person person; String arbitraryComment; } class Person { String firstName; String lastName; }I get xml structure like this:
<application> <person> <firstName>?</firstName> <lastName>?</lastName> </person> <arbitraryComment>?</arbitraryComment> </application>And I would want xml structure to be:
<application> <firstName>?</firstName> <lastName>?</lastName> <arbitraryComment>?</arbitraryComment> </application>Lokesh Gupta
Here root node is “application”. It is not possible (also not advisable) to avoid “person” node.