Suggestion to parse this XML in Java

Question

Not new to Java; but relatively new to XML-parsing. I know a tiny bit about a lot of the XML tools out there, but not much about any of them. I am also not an XML-pro.

Answer 1

OK, so I settled on a solution that (to me) seemed to address my needs in the most reasonable way. My apologies to the other suggestions, but I just liked this route better because it kept most of the parsing-rules as annotations and what little procedural-code I had to write was very minimal.

I ended up going with JAXB; initially I thought JAXB would either create XML from a Java-class or parse XML into a Java-class but only with an XSD. Then I discovered that JAXB has annotations that can parse XML into a Java-class without an XSD.

The XML-file I'm working with is huge and very deep, but I only need bits and bites of it here and there; I was worried that navigating what maps to where in the future would be very difficult. So I chose to structure a tree of folders modeled after the XML... each folder maps to an element and in each folder is a POJO representing that actual element.

Problem is, sometimes there is an element who has a child-element several levels down which has a single property I care about. It would be a pain to create 4 nested-folders and a POJO for each just to get access to a single property. But that's how you do it with JAXB (at least, from what I can tell); once again I was in a corner.

Then I stumbled on EclipseLink's JAXB-implementation: Moxy. Moxy has an @XPath annotation that I could place in that parent POJO and use to navigate several levels down to get access to a single property without creating all those folders and element-POJOs. Nice.

So I created something like this: (note: I chose to use getters for cases where I need to massage the value)

// maps to the root-"xml" element in the file
@XmlRootElement( name="xml" )
@XmlAccessorType( XmlAccessType.FIELD )
public class Xml {

    // this is standard JAXB
    @XmlElement;               
    private Item item;
    public Item getItem() {    
        return this.item;
    }

    ...
}

// maps to the ""-element in the file
public class Item {

    // standard JAXB; maps to ""
    @XmlAttribute              
    private String id;
    public String getId() {
        return this.id;
    }

    // getting an attribute buried deep down
    // MOXY; maps to ""
    @XmlPath( "rating/@average" )    
    private Double averageRating;
    public Double getAverageRating() {
        return this.average;
    }

    // getting a list buried deep down
    // MOXY; maps to ""
    @XmlPath( "service/identification/aliases/alias/text()" )
    private List aliases;
    public List getAliases() {
        return this.aliases;
    }

    // using a getter to massage the value
    @XmlElement(name="dateforindex")
    private String dateForIndex;
    public Date getDateForIndex() {
        // logic to parse the string-value into a Date
    }

}

Also note that I took the route of separating the XML-object from the model-object I actually use in the app. Thus, I have a factory that transforms these crude objects into much more robust objects which I actually use in my app.