Javax.xml.bind.JAXB.unmarshal() Method

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Description

The Javax.xml.bind.JAXB.unmarshal(URL xml, Class<T> type) method reads in a Java object tree from the given XML input.

Declaration

Following is the declaration for javax.xml.bind.JAXB.unmarshal(URL xml, Class<T> type) method

public static <T> T unmarshal(URL xml, Class<T> type)

Parameters

• xml − The resource pointed by the URL is read in its entirety.

• type − A class type to be unmarshaled.

Return Value

This method does not return any value.

Exception

NA

Example

The following example shows the usage of javax.xml.bind.JAXB.unmarshal(URL xml, Class<T> type) method. To proceed, consider the following Student class which will be used to have objects for marshalling purpose −

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 marshal ie. convert Student object into an XML file. Here we will creat Binder object using JAXBContext because we can not create Binder object directly because it is an abstract class. This example marshals the Student object and prints it at STDOUT, but in practical scenario you can store the object in any file as an XML node.

package com.tutorialspoint;

import java.io.IOException;
import java.net.URL;

import javax.xml.bind.JAXB;

public class JAXBDemo {
   public static void main(String[] args) throws IOException {
      
      try {         
         String s = "http://<web address>/Student.xml";
         URL url = new URL(s);
         
         // marshal object to file input stream
         Student st = JAXB.unmarshal(url, Student.class);
         
         // prints
         System.out.println("Age : "+st.getAge());
         System.out.println("Name : "+st.getName());
         
      }catch(Exception ex) {
         ex.printStackTrace();
      }
   }
}

Student.xml is input to the JAXBDemo program −

<?xml version = "1.0" encoding = "UTF-8" standalone = "yes"?>
<student id = "10">
   <age>12</age>
   <name>Malik</name>
</student>

Before we proceed for compilation, we need to make sure that that we download JAXB2.xxx.jar and put it in our CLASSPATH. Once setup is ready, let us compile and run the above program, this will produce the following result −

Age : 12
Name : Malik