convert java object using jaxb to xml and vice versa (marshal and unmarshal)

Question

I am suppose to have a method called save() which should marshal the list of computer parts in the right panel to an XML file. In reverse, another method called

Answer 1

Just create a class Parts to hold a List<String>. Then you can just marshal/unmarshal to an instance of that class.

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Parts {

    @XmlElement(name = "part")
    private List<String> part;

    public List<String> getPart() { return part; }
    public void setPart(List<String> part) { this.part = part; }
}

As for the marshalling (save), you would create a Marshaller by creating a JAXBContext using the Parts class. The just call marshal on the marshaller.

See some of the overloaded marshal methods (notice File)

private void doSaveCommand() throws Exception {
    ArrayList<String> save = new ArrayList<>();
    for (int i = 0; i < destination.size(); i++) {
        save.add((String)destination.getElementAt(i));
    }
    Parts parts = new Parts();
    parts.setPart(save);
    JAXBContext context = JAXBContext.newInstance(Parts.class);
    Marshaller marshaller = context.createMarshaller();
    marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
    marshaller.marshal(parts, System.out);
}

Note you have a little design problem. The DefaultListModels that need to be accessed, can't be because the listener code is in a static context, and models are not static. I just made the models static to get it to work, but you'll want to redesign your code a bit. Here is the result (to standard output - you will to marshal to file).

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<parts>
    <part>Case</part>
    <part>Motherboard</part>
    <part>CPU</part>
</parts>

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I'll let you work on the unmarshalling on your own. This should get you started.

Some Resource

• Marshaller API doc has some examples
• Unmarshaller API doc has some examples
• JAXContext API doc has some explanation about the context
• General JAXB tutorial