JAVA EE: XML Marshalling and UnMarshalling using Spring and JAXB XML binding framework

Sunday, 20 January 2019

XML Marshalling and UnMarshalling using Spring and JAXB XML binding framework - XML Config

Want to Level Up Your Java & Spring Skills?

Subscribe to Ram N Java for clean, step-by-step programming guides and hands-on developer tutorials!

What is Object-XML Mapping (OXM) in Spring?

Spring's Object/XML Mapping (OXM) framework provides an abstraction layer over standard XML binding libraries like JAXB, Castor, and XStream. It allows developers to seamlessly convert between Java objects and XML structures:

Marshalling: Serializing a Java entity into structured XML data.
Unmarshalling: Deserializing XML data back into a usable Java object.

Configuring JAXB via Spring XML Configuration

Using an XML configuration file allows you to configure your Spring beans declaratively. By defining Jaxb2Marshaller inside your application context XML, you separate mapping configuration from Java source code, making it straightforward to manage across different environments.

Key Steps Demonstrated in This Guide

Bean Definitions: Declaring the Jaxb2Marshaller bean inside applicationContext.xml.
Class Binding: Setting up domain model classes with required JAXB mappings.
Marshalling Process: Passing a Java object to the marshaller to generate XML output.
Unmarshalling Process: Reading the generated XML and reconstructing the original Java object.

Recommended Related Tutorials

Click here to watch on Youtube:
https://www.youtube.com/watch?v=1GLuPkkXmTA&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge:

XML Marshalling and UnMarshalling using Spring and JAXB XML binding framework - XML Config

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.ram.core</groupId>

    <artifactId>SpringDemo</artifactId>

    <packaging>jar</packaging>

    <version>1.0-SNAPSHOT</version>

    <name>SpringDemo</name>

    <url>http://maven.apache.org</url>

    <properties>

        <spring.version>5.1.1.RELEASE</spring.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.8.2</version>

            <scope>test</scope>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-core</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-context</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-oxm</artifactId>

            <version>${spring.version}</version>

        </dependency>

    </dependencies>

</project>

Company.java

package com.ram.core.model;

import javax.xml.bind.annotation.XmlAccessType;

import javax.xml.bind.annotation.XmlAccessorType;

import javax.xml.bind.annotation.XmlAttribute;

import javax.xml.bind.annotation.XmlElement;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "CompanyInfo", namespace = "com.ram.core")

@XmlAccessorType(XmlAccessType.NONE)

public class Company

{

    @XmlAttribute(name = "Id")

    private Integer id;

    @XmlElement(name = "CompanyName")

    private String companyName;

    @XmlElement(name = "CEO_Name")

    private String ceoName;

    @XmlElement(name = "Number_Of_Employees")

    private Integer numberOfEmployees;

    public Integer getId()

    {

        return id;

    }

    public void setId(Integer id)

    {

        this.id = id;

    }

    public String getCompanyName()

    {

        return companyName;

    }

    public void setCompanyName(String companyName)

    {

        this.companyName = companyName;

    }

    public String getCeoName()

    {

        return ceoName;

    }

    public void setCeoName(String ceoName)

    {

        this.ceoName = ceoName;

    }

    public Integer getNumberOfEmployees()

    {

        return numberOfEmployees;

    }

    public void setNumberOfEmployees(Integer numberOfEmployees)

    {

        this.numberOfEmployees = numberOfEmployees;

    }

    @Override

    public String toString()

    {

        return "Company [id=" + id + ", companyName=" + companyName

                + ", ceoName=" + ceoName + ", numberOfEmployees="

                + numberOfEmployees + "]";

    }

}

XMLConverter.java

package com.ram.core;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import javax.xml.transform.stream.StreamResult;

import javax.xml.transform.stream.StreamSource;

import org.springframework.oxm.Marshaller;

import org.springframework.oxm.Unmarshaller;

public class XMLConverter

{

    private Marshaller marshaller;  

    private Unmarshaller unmarshaller;

    public Marshaller getMarshaller()

    {

        return marshaller;

    }

    public void setMarshaller(Marshaller marshaller)

    {

        this.marshaller = marshaller;

    }

    public Unmarshaller getUnmarshaller()

    {

        return unmarshaller;

    }

    public void setUnmarshaller(Unmarshaller unmarshaller)

    {

        this.unmarshaller = unmarshaller;

    }

    public void convertFromObjectToXML(Object object, String filepath)

            throws IOException

    {

        FileOutputStream os = null;

        try

        {

            os = new FileOutputStream(filepath);

            getMarshaller().marshal(object, new StreamResult(os));

        }

        finally

        {

            if (os != null)

            {

                os.close();

            }

        }

    }

    public Object convertFromXMLToObject(String xmlfile)

            throws IOException

    {

        FileInputStream is = null;

        try

        {

            is = new FileInputStream(xmlfile);

            return getUnmarshaller().unmarshal(new StreamSource(is));

        }

        finally

        {

            if (is != null)

            {

                is.close();

            }

        }

    }

}

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://www.springframework.org/schema/beans

    http://www.springframework.org/schema/beans/spring-beans-4.3.xsd">

    <bean id="XMLConverter" class="com.ram.core.XMLConverter">

        <property name="marshaller" ref="jaxbMarshaller" />

        <property name="unmarshaller" ref="jaxbMarshaller" />

    </bean>

    <bean id="jaxbMarshaller"

        class="org.springframework.oxm.jaxb.Jaxb2Marshaller">

        <property name="packagesToScan" value="com.ram.core.model" />

        <property name="marshallerProperties">

            <map>

                <entry key="jaxb.formatted.output">

                    <value type="boolean">true</value>

                </entry>

            </map>

        </property>

    </bean>

</beans>

App.java

package com.ram.core;

import java.io.IOException;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.ram.core.model.Company;

public class App

{

    private static final String XML_FILE_NAME = "company.xml";

    public static void main(String[] args) throws IOException

    {

        ApplicationContext context = new ClassPathXmlApplicationContext(

                "applicationContext.xml");

        XMLConverter converter = (XMLConverter) context

                .getBean(XMLConverter.class);

        // Perform Marshaling

        Company company = new Company();

        company.setId(201);

        company.setCompanyName("Google");

        company.setCeoName("Peter");

        company.setNumberOfEmployees(50000);

        // from object to XML file

        converter.convertFromObjectToXML(company, XML_FILE_NAME);

        System.out.println("Converted Object to XML!");

        // from XML to object

        Company company2 = (Company) converter

                .convertFromXMLToObject(XML_FILE_NAME);

        System.out.println(company2);

        System.out.println("Converted XML to Object!");

    }

}

Output:

Converted Object to XML!

Company [id=201, companyName=Google, ceoName=Peter, numberOfEmployees=50000]

Converted XML to Object!

company.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<ns2:CompanyInfo xmlns:ns2="com.ram.core" Id="201">

    <CompanyName>Google</CompanyName>

    <CEO_Name>Peter</CEO_Name>

    <Number_Of_Employees>50000</Number_Of_Employees>

</ns2:CompanyInfo>