Javax.xml.bind.JAXBContext.createUnmarshaller() Method

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Description

The Javax.xml.bind.JAXBContext.createUnmarshaller() create an Unmarshaller object that can be used to convert XML data into a java content tree.

Declaration

Following is the declaration for javax.xml.bind.JAXBContext.createUnmarshaller() method −

public abstract Unmarshaller createUnmarshaller()

Parameters

NA

Return Value

This method returns an Unmarshaller object

Exception

JAXBException − if an error was encountered while creating the Unmarshaller object.

Example

The following example shows the usage of javax.xml.bind.JAXBContext.createUnmarshaller() method.

package com.tutorialspoint;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
 
@XmlRootElement
public class Student{
 
   String name;
   int age;
   int id;

   public String getName(){
      return name;
   }

   @XmlElement
   public void setName(String name){
      this.name = name;
   }

   public int getAge(){
      return age;
   }

   @XmlElement
   public void setAge(int age){
      this.age = age;
   }

   public int getId(){
      return id;
   }

   @XmlAttribute
   public void setId(int id){
      this.id = id;
   }
}

Now let us create main class which will be used to create Unmarshaller object for unmarshalling ie. convert Student.xml to JAXB object. This example unmarshals the Student.xml file to JAXB object and prints the XML node values.

package com.tutorialspoint;

import java.io.FileInputStream;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;

public class JAXBContextDemo {
   public static void main(String[] args) {

      try {
         // create JAXBContext which will be used to create a Binder
         JAXBContext jc = JAXBContext.newInstance(Student.class);
        
         // create new file input stream
         FileInputStream fis = new FileInputStream("Student.xml");
         
         // unmarshaller obj to convert xml data to java content tree
         Unmarshaller u = jc.createUnmarshaller();
         
         // unmarshaller xml data to java content tree
         Student s = (Student)u.unmarshal(fis);
         
         // prints
         System.out.println("Age: "+s.getAge());
         System.out.println("Name: "+s.getName());
  
      }catch(Exception ex) {
         ex.printStackTrace();
      }
   }
}

To create document, an XML file is needed as input. The XML file is named as Student.xml−

<?xml version = "1.0" encoding = "UTF-8" standalone = "no"?>
<student id = "10">
   <age>14</age>
   <name>Soniya</name>
</student>

Let us compile and run the above program, this will produce the following result −

Age: 14
Name: Soniya