represent xml as java classes

Question

Probably this question might have been asked. I am new to the conversion of xml to java classes. I have an xml like this:

<Root>
    <Book name="harel" price="5" />
    <Book name="xml" price="9" />
</Root>

IS there a way to generate java classes dynamicaly for a structure like this ? A small correction, i don't have an xsd for the xml

Answer 1

Note: I'm the EclipseLink JAXB (MOXy) lead and a member of the JAXB (JSR-222) expert group.

IS there a way to generate java classes dynamicaly for a structure like this ?

JAXB implementations provide the ability to generate a Java model from an XML schema. The reference implementation which is included in the JDK starting in Java SE 6 is available at:

<JAVA_HOME>/bin/xjc

An example of generating an object model from an XML schema can be found here:

• http://blog.bdoughan.com/2010/09/processing-atom-feeds-with-jaxb.html

A small correction, i don't have an xsd for the xml

If you don't have an XML schema you could find a utility to generate an XML schema from an XML document:

• Any tools to generate an XSD schema from an XML instance document?

Or start from code.

---

STARTING FROM CODE

You can also start from code and annotate your model to map to the existing XML structure.

Root

package forum11213872;

import java.util.List;
import javax.xml.bind.annotation.*;

@XmlRootElement(name="Root")
@XmlAccessorType(XmlAccessType.FIELD)
public class Root {

    @XmlElement(name="Book")
    private List<Book> books;

}

Book

package forum11213872;

import javax.xml.bind.annotation.*;

@XmlAccessorType(XmlAccessType.FIELD)
public class Book {

    @XmlAttribute
    private String name;

    @XmlAttribute
    private int price;

}

Demo

package forum11213872;

import java.io.File;
import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Root.class);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        File xml = new File("src/forum11213872/input.xml");
        Root root = (Root) unmarshaller.unmarshal(xml);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(root, System.out);
    }

}

input.xml/Output

<Root>
    <Book name="harel" price="5" />
    <Book name="xml" price="9" />
</Root>

Answer 2

是的，请参阅castor框架（http://www.castor.org/）或jaxb（http://www.oracle.com/technetwork/articles/javase/index-140168.html）

Answer 3

Try Java Castor. You can specify a xsd and convert it to object. There is also a plugin for Eclipse.

http://www.castor.org/

Answer 4

Have a look at XStream .

It converts between XML and Java and between Java and XML.

Answer 5

Use JAXB , it is included in JavaSE now and you can use XJC to generate the classes from an XSD. However if you truly mean dynamically as in the structure of the XML isn't known till runtime you will need to use something like JDOM .