JAXB集合映射

Question

I'm new in dealing with XML in Java, but one of services I use returns it as result. Until now, I've dealt with mapping XML into POJO, using @XmlRootElement -like annotations. But now I have absolutely no idea to do with this document:

<?xml version="1.0" encoding="windows-1251"?>
<response>
    <status>
        <code>0</code>
    </status>
    <result>
        <limit>2</limit>
        ...

        <data>
            <row0>
                <ID>85427</ID>
                <name>Default</name>
                <siteID>40628</siteID>
                 ... some elements
            </row0>
        </data>
    </result>
</response>

Until now, I used these classes to bind XML (except 'data' node) into POJO:

@XmlRootElement(name="response")
public class Response {

    private Status status;

    private String result;

    public Status getStatus() {
        return status;
    }

    @XmlElement(name = "status")
    public void setStatus(Status status) {
        this.status = status;
    }

    public String getResult() {
        return result;
    }

    @XmlElement(name ="result")
    public void setResult(String result) {
        this.result = result;
    }
}



@XmlRootElement(name = "status")
public class Status {

    private String ID;
    private String code;
    private String error;

    public String getID() {
        return ID;
    }

    @XmlElement(name = "ID")
    public void setID(String ID) {
        this.ID = ID;
    }

    public String getCode() {
        return code;
    }

    @XmlElement(name = "code")
    public void setCode(String code) {
        this.code = code;
    }

    public String getError() {
        return error;
    }

    @XmlElement(name = "error")
    public void setError(String error) {
        this.error = error;
    }
}

But now I need to bind content as collection of elements. I've looked for examples, and everywhere people use specific tag to define root element for collection's item, but in this document, root tags will be as <row0> , <row1> etc.

I use Jackson, which, if I understand correctly, uses JAXB annotations to define XML to POJO bind rules. So could this deal be solved this way, or I have to manipulate this document in DOM-style?

Answer 1

You can solve your problem by using something like this :

Create your Row class that represents your <row0>,<row1> etc... and map it with JAXB like you would do it normally.

Then create a class that extends XmlAdapter<List<Row>,List<Element>> and define the abstracts methods marshall and unmarshall.

Here is some Javadoc to help you :

XmlAdapter : http://docs.oracle.com/javaee/5/api/javax/xml/bind/annotation/adapters/XmlAdapter.html

Element : http://docs.oracle.com/javase/1.5.0/docs/api/org/w3c/dom/Element.html

Then create a Data class :

public class Data{

    private List<Row> rows;

    public List<Row> getRows() {
        return rows;
    }

    @XmlAnyElement
    @XmlJavaTypeAdapter(MyRowsAdapter.class)
    public void setRows(List<Row> result) {
        this.rows = rows;
    }

}

Then you can add this mapping to your Response class :

private Data data;

public Data getData() {
    return data;
}

@XmlElement(name="data")
public void setData(Data data) {
    this.data = data;
}

Note that for this solution to work, your <data> element must only contains elements like your Row.

Also, you cannot use @XmlElementWrapper instead of using a Data class because of a bug in JAXB which make incompatible @XmlElementWrapper and @XmlJavaTypeAdapter : https://java.net/jira/browse/JAXB-787