package com.company.model.entities;
 
public class User {
	private Integer id;
	private Integer code;
	private String name;
 
	public User() {}
 
	public User(Integer id, Integer code, String name) {
		super();
		this.id = id;
		this.code = code;
		this.name = name;
	}
 
	public Integer getId() {
		return id;
	}
 
	public void setId(Integer id) {
		this.id = id;
	}
 
	public Integer getCode() {
		return code;
	}
 
	public void setCode(Integer code) {
		this.code = code;
	}
 
	public String getName() {
		return name;
	}
 
	public void setName(String name) {
		this.name = name;
	}
 
 
}

package com.company.model.entities;
 
public class Product {
	private Integer id;
	private Long code;
	private String description;
 
	public Product() {}
 
	public Product(Integer id, Long code, String description) {
		super();
		this.id = id;
		this.code = code;
		this.description = description;
	}
 
	public Integer getId() {
		return id;
	}
 
	public void setId(Integer id) {
		this.id = id;
	}
 
	public Long getCode() {
		return code;
	}
 
	public void setCode(Long code) {
		this.code = code;
	}
 
	public String getDescription() {
		return description;
	}
 
	public void setDescription(String description) {
		this.description = description;
	}
 
 
}

package com.company.model.jaxb;
 
import java.util.List;
 
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
 
import com.company.model.entities.Product;
import com.company.model.entities.User;
 
@XmlRootElement(name="report")
@XmlAccessorType(XmlAccessType.FIELD)
public class Report {
	@XmlElement(name="user")
	private List<User> users;
	@XmlElement(name="product")
	private List<Product> products;
 
	public Report() {}
 
	public List<User> getUsers() {
		return users;
	}
 
	public void setUsers(List<User> users) {
		this.users = users;
	}
 
	public List<Product> getProducts() {
		return products;
	}
 
	public void setProducts(List<Product> products) {
		this.products = products;
	}
 
 
}

package com.company.model.jaxb;
import java.io.File;
 
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
 
import com.company.model.jaxb.Report;
 
 
public class ReportMarshaller<T> {
	private static JAXBContext jaxbContext;
 
	public ReportMarshaller() throws JAXBException {
		jaxbContext = JAXBContext.newInstance(Report.class);
	}
 
	public void marshal(Report report, File output) throws JAXBException {
		Marshaller marshaller = jaxbContext.createMarshaller();
		marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
		marshaller.marshal(report, output);
	}
 
	public Report unmarshal(File input) throws JAXBException {
		Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
		Report report = (Report) unmarshaller.unmarshal(input);
		return report;
	}
 
}

package com.company.main;
 
import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
 
import javax.xml.bind.JAXBException;
 
import com.company.model.entities.Product;
import com.company.model.entities.User;
import com.company.model.jaxb.Report;
import com.company.model.jaxb.ReportMarshaller;
 
public class Main {
 
	public static void main(String[] args) {
		List<User> users = new ArrayList<>();
		List<Product> products = new ArrayList<>();
		Report report = new Report();
		ReportMarshaller<Report> marshaller = null;
 
		Collections.addAll(users,
			new User(20, 001, "John Doe"),
			new User(30, 002, "Homer Simpson"),
			new User(40, 003, "Peter Griffin")
		);
		Collections.addAll(products,
				new Product(10, 123456789123456789L, "Jabón antibacterial"),
				new Product(20, 987654321987654321L, "Shampoo control caspa")
		);
		report.setUsers(users);
		report.setProducts(products);
 
		try {
			marshaller = new ReportMarshaller<Report>();
			marshaller.marshal(report, new File("D://test.xml"));
			System.out.println("Leyendo el XML...");
			System.out.println();
			report = null;
			report = marshaller.unmarshal(new File("D://test.xml"));
			System.out.println("Usuarios:\n");
			for(User user : report.getUsers()) {
				System.out.println(user.getId());
				System.out.println(user.getCode());
				System.out.println(user.getName());
			}
                        System.out.println("\nProductos:\n");
			for(Product product : report.getProducts()) {
				System.out.println(product.getId());
				System.out.println(product.getCode());
				System.out.println(product.getDescription());
			}
		} catch (JAXBException e) {
			e.printStackTrace();
		}
 
	}
 
}

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<report>
    <user>
        <code>1</code>
        <id>20</id>
        <name>John Doe</name>
    </user>
    <user>
        <code>2</code>
        <id>30</id>
        <name>Homer Simpson</name>
    </user>
    <user>
        <code>3</code>
        <id>40</id>
        <name>Peter Griffin</name>
    </user>
    <product>
        <code>123456789123456789</code>
        <description>Jabón antibacterial</description>
        <id>10</id>
    </product>
    <product>
        <code>987654321987654321</code>
        <description>Shampoo control caspa</description>
        <id>20</id>
    </product>
</report>

Leyendo el XML...

Usuarios:

20
1
John Doe
30
2
Homer Simpson
40
3
Peter Griffin

Productos:

10
123456789123456789
Jabón antibacterial
20
987654321987654321
Shampoo control caspa