how to parse xml to java object?

Question

I have an XML file which is used to config some rules, it does not has complex structure, but this configuration is used anywhere in my system, so I want to parse this XML to java object and design as singleton mode, is any good way I can use it to unmarshal XML to Java object directly without write much codes?

I did some research on Google and known JAXB is choice, I used xjc to generate java object source class according xsd file, after unmarshal I will directly get these configurationType object, is it necessary I convert again, I see most coders did this, but why? Because they are some data, just from the object generated to JAXB and copy to yourself created POJO object

Answer 1

JAXB is an ideal solution. But you don’t necessarily need xsd and xjc for that. More often than you don’t have an xsd but you know what your xml is. Simple analyze xml, e.g.,

<customer id="100">

    <age>29</age>

    <name>mkyong</name>

</customer>

Create necessary model class:

@XmlRootElement

public class Customer {

    String name;

    int age;

    int id;

    public String getName() {

        return name;

    }

    @XmlElement

    public void setName(String name) {

        this.name = name;

    }

    public int getAge() {

        return age;

    }

    @XmlElement

    public void setAge(int age) {

        this.age = age;

    }

    public int getId() {

        return id;

    }

    @XmlAttribute

    public void setId(int id) {

        this.id = id;

    }

}

Try to unmarshal:

JAXBContext jaxbContext = JAXBContext.newInstance(Customer.class);

Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();

Customer customer = (Customer) jaxbUnmarshaller.unmarshal(new File("C:\\file.xml"));

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