Java Jackson XML to POJO

1. Introduction

Jackson is a popular library in Java for handling JSON, but it also provides capabilities to process XML. Converting XML to a Plain Old Java Object (POJO) can be a common requirement when dealing with XML data in Java applications. In this tutorial, we will explore how to use Jackson to convert XML data into a Java object.

2. Example Steps

1. Add the Jackson XML library dependencies to your project.

2. Create a Java class (POJO) representing the structure of your XML data.

3. Utilize the XmlMapper from Jackson to convert the XML string into a Java object.

4. Display the Java object to validate the XML to POJO conversion.

3. Java Jackson XML to POJO Example

import com.fasterxml.jackson.dataformat.xml.XmlMapper;

public class JacksonXmlToPojoExample {

    public static void main(String[] args) {
        try {
            // Sample XML string
            String xmlString = "<user><id>1</id><name>John Doe</name></user>";

            // Instantiate XmlMapper
            XmlMapper xmlMapper = new XmlMapper();

            // Convert XML string to User object
            User user = xmlMapper.readValue(xmlString, User.class);
            System.out.println("Converted Java Object: " + user);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    static class User {
        private int id;
        private String name;

        // Getters and setters
        public int getId() { return id; }
        public void setId(int id) { this.id = id; }
        public String getName() { return name; }
        public void setName(String name) { this.name = name; }

        @Override
        public String toString() {
            return "User [id=" + id + ", name=" + name + "]";
        }
    }
}

Output:

Converted Java Object: User [id=1, name=John Doe]

4. Step By Step Explanation

1. We have created a User class that represents the structure of our XML data. This class has two fields, id and name.

2. The XmlMapper class is a part of Jackson's XML data format module. It is specialized for converting XML data into Java objects and vice-versa.

3. We instantiate XmlMapper and then use its readValue method to convert our XML string into a User object.

4. The resulting Java object is printed to the console, which confirms that the XML data has been successfully mapped to our POJO.

For this to work seamlessly, make sure to include the appropriate Jackson XML dependencies in your project. This functionality is helpful when dealing with legacy systems that communicate using XML or when working with various XML APIs.