Convert POJO to XML using the Jackson library in Java?

Jackson is a library that allows you to convert Java objects into XML and vice versa. In this example, we will demonstrate how to convert a POJO (Plain Old Java Object) into XML using the Jackson library.

Well, if you are not familiar with POJO, it is a simple Java object that does not follow any specific framework or design pattern. It is just a regular Java class with fields and methods.

We will use the method writeValueAsString() of the XmlMapper class to convert a POJO into XML. The XmlMapper class is part of the Jackson library and it is used for XML serialization and deserialization.

For example, consider the following POJO:

public class Person {
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

To convert this POJO into XML using Jackson, you need to add the Jackson library to your project. You can do this by adding the following dependency to your pom.xml file if you are using Maven:

<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
    <version>2.12.3</version>
</dependency>   

If you are not using Maven, you can download the Jackson library from here.

Steps to Convert POJO to XML using Jackson in Java

Following are the steps to convert a POJO to XML using Jackson in Java:

• Define your POJO class (e.g., Person) with fields and getters.
• Import the necessary Jackson classes.
• Create an instance of the POJO and XmlMapper.
• Use the writeValueAsString() method of the XmlMapper class to convert the POJO to XML.

Example

In the below example, we will create a class Person with fields for name and age. We will then convert this POJO into XML using Jackson.

Following is the code to convert POJO to XML using Jackson in Java:

import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class PojotoXmlEx{
   public static void main(String[] args) throws IOException {
      // Create an instance of the Person class
      Person person = new Person("Ansh", 23);

      // Create an instance of XmlMapper
      XmlMapper xmlMapper = new XmlMapper();

      // Convert the Person object to XML
      String xml = xmlMapper.writeValueAsString(person);

      System.out.println(xml);
   }
}
class Person {
   private String name;
   private int age;

   public Person(String name, int age) {
      this.name = name;
      this.age = age;
   }

   public String getName() {
      return name;
   }

   public int getAge() {
      return age;
   }
}

Output

<?xml version="1.0" encoding="UTF-8"?>
<person>
  <name>Ansh</name>
  <age>23</age>
</person>