Question

When talking about object marshalling in most of the Java-XML data binding APIs, it has been said that the the XML file is recreated from the user defined classes from memory? I’m quite confusing about saying (user defined classes from memory). I know using reflection will help to get the class names and/or fields in case of need for implementing the marshalling process, but how the data (values for the elements or attributes) can be accessed?

Is there any one can explain this process a little?

thanks

Answer 1

You can access them using reflection. Reflection doesn’t returns just the name but the value that a field hold for example.

A simple example could be obtained with the following code:

import java.lang.reflect.Field;

public class ReflectionTest {

    public static void main(final String[] args) throws Exception {
        Object obj = new Person("Person Name", 20);

        for (Field f : obj.getClass().getDeclaredFields()) {
            f.setAccessible(true);
            System.out.println(f.getName() + " = " + f.get(obj));
        }
    }

    public static class Person {
        private final String name;
        private final int age;

        public Person(final String name, final int age) {
            super();
            this.name = name;
            this.age = age;
        }

    }

}

This code would print out:

name = Person Name
age = 20

As you can see the values of each field is accessed using method Field.get(Object). You can find more out here.