JAXB

JAXB stands for Java Architecture for XML Binding. JAXB is an API and provides mechanism to marshal (write) java objects into XML and unmarshal (read) XML into object. Simply, JAXB used to convert Java Object into XML and XML into Java Object.

✓ JAXB Annotations

Annotation	Scope	Description
@XmlRootElement	Class and Enum	Defines the XML root element. Root Java classes need to be registered with the JAXB context when it is created.
@XmlAccessorType	Package and Class	Defines the fields and properties of your Java classes that the JAXB engine uses for binding. It has four values: PUBLIC_MEMBER, FIELD, PROPERTY and NONE.
@XmlAccessorOrder	Package and Class	Defines the sequential order of the children.
@XmlType	Class and Enum	Maps a Java class to a schema type. It defines the type name and order of its children.
@XmlElement	Field	Maps a field or property to an XML element
@XmlAttribute	Field	Maps a field or property to an XML attribute
@XmlTransient	Field	Prevents mapping a field or property to the XML Schema
@XmlValue	Field	Maps a field or property to the text value on an XML tag.
@XmlList	Field and Parameter	Maps a collection to a list of values separated by space.
@XmlElementWrapper	Field	Maps a Java collection to an XML wrapped collection

✓ Convert Java Object To XML (Marshalling Example) package com.jst.jaxb;
import java.io.Serializable;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "student")
@XmlAccessorType(XmlAccessType.PROPERTY)
public class Student implements Serializable {
private static final long serialVersionUID = 1L;
private Integer id;
private String firstName;
private String lastName;
private Department department;
public Student() {
super();
}
public Student(Integer id, String firstName, String lastName, Department department) {
super();
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.department = department;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public Department getDepartment() {
return department;
}
public void setDepartment(Department department) {
this.department = department;
}
public static long getSerialversionuid() {
return serialVersionUID;
}
@Override
public String toString() {
return "Student [ID = " + id + ", First Name = " + firstName + ", Last Name = " + lastName + ", Department [ID = " + department.getId() + ", First Name = " + department.getFirstName() +"]" + "]";
}
}

package com.jst.jaxb;
public class Department {
private Integer id;
private String firstName;
public Department() {
super();
}
public Department(Integer id, String firstName) {
super();
this.id = id;
this.firstName = firstName;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
}

package com.jst.jaxb;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
public class ObjectToXml {
public static void main(String[] args) {
Student student = new Student(1001, "Naga Vijay", "Jaladhi", new Department(1001, "CSE"));
convertObjectToXml(student);
}
private static void convertObjectToXml(Student student) {
try {
JAXBContext jaxbContext = JAXBContext.newInstance(Student.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
jaxbMarshaller.marshal(student, System.out);
} catch (JAXBException e) {
e.printStackTrace();
}
}
}

Output :  <student> <department> <firstName>CSE</firstName> <id>1001</id> </department> <firstName>Naga Vijay</firstName> <id>1001</id> <lastName>Jaladhi</lastName> </student> ✓ Convert XML To Java Object (Unmarshaller Example) package com.jst.jaxb;
import java.io.Serializable;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "student")
@XmlAccessorType(XmlAccessType.PROPERTY)
public class Student implements Serializable {
private static final long serialVersionUID = 1L;
private Integer id;
private String firstName;
private String lastName;
private Department department;
public Student() {
super();
}
public Student(Integer id, String firstName, String lastName, Department department) {
super();
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.department = department;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public Department getDepartment() {
return department;
}
public void setDepartment(Department department) {
this.department = department;
}
public static long getSerialversionuid() {
return serialVersionUID;
}
@Override
public String toString() {
return "Student [ID = " + id + ", First Name = " + firstName + ", Last Name = " + lastName + ", Department [ID = " + department.getId() + ", First Name = " + department.getFirstName() +"]" + "]";
}
}

package com.jst.jaxb;
public class Department {
private Integer id;
private String firstName;
public Department() {
super();
}
public Department(Integer id, String firstName) {
super();
this.id = id;
this.firstName = firstName;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
}

package com.jst.jaxb;
import java.io.File;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
public class XmlToObject {
public static void main(String[] args) {
String fileName = "C:\\Intel\\student.xml";
convertXmlFileToObject(fileName);
}
private static void convertXmlFileToObject(String fileName) {
File xmlFile = new File(fileName);
JAXBContext jaxbContext;
try {
jaxbContext = JAXBContext.newInstance(Student.class);
Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
Student student = (Student) jaxbUnmarshaller.unmarshal(xmlFile);
System.out.println(student);
} catch (JAXBException e) {
e.printStackTrace();
}
}
}

Input :  <student> <department> <firstName>CSE</firstName> <id>1001</id> </department> <firstName>Naga Vijay</firstName> <id>1001</id> <lastName>Jaladhi</lastName> </student> Output : Student [ID = 1001, First Name = Naga Vijay, Last Name = Jaladhi, Department [ID = 1001, First Name = CSE]]

✓ Convert XML To Java Object (Unmarshaller Example) package com.jst.jaxb;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
@XmlRootElement(name = "Person")
@XmlType(propOrder = {"id", "name", "age", "gender"})
public class Person {
private int id;
private int age;
private String name;
private String gender;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
@Override
public String toString() {
return "Person [ID =" + id + ", Age = " + age + ", Name = " + name + ", Gender = " + gender + "]";
}
}

package com.jst.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;
public class JaxbExample {
private static final String FILE_NAME = "C:\\Intel\\person.xml";
public static void main(String[] args) {
Person person = new Person();
person.setId(2001);
person.setName("David Ping");
person.setAge(40);
person.setGender("Male");
convertObjectToXML(person);
Person personFromFile = convertXMLToObject();
System.out.println(personFromFile.toString());
}
private static void convertObjectToXML(Person person) {
try {
JAXBContext context = JAXBContext.newInstance(Person.class);
Marshaller marshaller = context.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
marshaller.marshal(person, new File(FILE_NAME));
} catch (JAXBException e) {
e.printStackTrace();
}
}
private static Person convertXMLToObject() {
try {
JAXBContext context = JAXBContext.newInstance(Person.class);
Unmarshaller unmarshaller = context.createUnmarshaller();
Person person = (Person) unmarshaller.unmarshal(new File(FILE_NAME));
return person;
} catch (JAXBException e) {
e.printStackTrace();
}
return null;
}
}
Marshaller Output :  <Person> <id>2001</id> <name>David Ping</name> <age>40</age> <gender>Male</gender> </Person> Unmarshaller Input :  <Person> <id>2001</id> <name>David Ping</name> <age>40</age> <gender>Male</gender> </Person> Unmarshaller Output : Person [ID =2001, Age = 40, Name = David Ping, Gender = Male]

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JAXB