Introduction

XML (Extensible Markup Language) and JSON (JavaScript Object Notation) are both widely used formats for data storage and transfer. While XML is often used for document storage and data interchange, JSON has become the preferred format for APIs and web applications due to its simplicity and readability.

In this blog, we'll explore how to convert and store XML content into JSON format, which is a common task when migrating legacy systems or integrating XML-based services with modern applications that use JSON.

Understanding the Need for Converting XML to JSON

XML and JSON both serve as ways to represent structured data, but they have different syntaxes and structures.

Key differences:

• XML uses a hierarchical structure with tags, attributes, and values, making it more verbose.
• JSON uses a lightweight, key-value pair format that is easier to read and parse in modern applications.

Converting XML data into JSON makes it easier to process and interact with, especially when integrating with JavaScript or when sending data via APIs.

Steps to Convert and Store XML Content into JSON

1. Use a Library to Parse XML

To convert XML to JSON in a programming environment, it’s best to use a library that can parse the XML and convert it into a format suitable for conversion to JSON. Most modern programming languages, like Python, Java, or JavaScript, offer libraries to perform this conversion.

Example in Python using xmltodict:

First, you’ll need to install the xmltodict library, which can easily convert XML to JSON.

pip install xmltodict

Then, you can use the following code to convert XML content into JSON:

import xmltodict
import json

# Sample XML data
xml_data = """<?xml version="1.0" encoding="UTF-8"?>
<person>
  <name>John Doe</name>
  <age>30</age>
  <city>New York</city>
</person>"""

# Parse XML to dictionary
dict_data = xmltodict.parse(xml_data)

# Convert dictionary to JSON
json_data = json.dumps(dict_data, indent=4)

print(json_data)

Output:

{
    "person": {
        "name": "John Doe",
        "age": "30",
        "city": "New York"
    }
}

2. Use a Library for JSON Serialization

After converting the XML data to a dictionary (or a similar structure), the next step is to serialize it into JSON format. Most languages, including Python, provide built-in methods to convert dictionaries or objects into JSON data.

In JavaScript, using xml2js library:

To use the xml2js library, install it first:

npm install xml2js

Then, you can parse XML and store the content into JSON as follows:

const xml2js = require('xml2js');

const xmlData = `<?xml version="1.0" encoding="UTF-8"?>
<person>
  <name>John Doe</name>
  <age>30</age>
  <city>New York</city>
</person>`;

const parser = new xml2js.Parser();

parser.parseString(xmlData, (err, result) => {
  if (err) {
    console.log('Error parsing XML:', err);
  } else {
    const jsonData = JSON.stringify(result, null, 4);
    console.log(jsonData);
  }
});

Output:

{
  "person": {
    "name": ["John Doe"],
    "age": ["30"],
    "city": ["New York"]
  }
}

3. Store the JSON Data

Once the XML data is successfully converted to JSON, you can store it as needed:

Write it to a JSON file.

Store it in a database.

Send it over an API.

Example of storing in a file (Python):

with open("output.json", "w") as json_file:
    json.dump(dict_data, json_file, indent=4)

Example of storing in a file (Node.js):

const fs = require('fs');

fs.writeFile("output.json", jsonData, (err) => {
  if (err) {
    console.log("Error writing file:", err);
  } else {
    console.log("JSON data has been written to output.json");
  }
});

4. Handling Nested XML Structures

XML files can have deeply nested structures, which can be more complicated to convert into JSON. Make sure the library you are using supports complex or deeply nested XML elements.

Example of a more complex XML:

<catalog>
  <book>
    <title>XML for Beginners</title>
    <author>John Doe</author>
    <price>19.99</price>
  </book>
  <book>
    <title>Advanced XML</title>
    <author>Jane Smith</author>
    <price>29.99</price>
  </book>
</catalog>

After conversion, the resulting JSON may look like this:

{
  "catalog": {
    "book": [
      {
        "title": ["XML for Beginners"],
        "author": ["John Doe"],
        "price": ["19.99"]
      },
      {
        "title": ["Advanced XML"],
        "author": ["Jane Smith"],
        "price": ["29.99"]
      }
    ]
  }
}

Libraries like xml2js and xmltodict handle nested elements well, so the resulting JSON will reflect the hierarchical structure of the original XML.

Conclusion

Converting XML to JSON is a simple process when using the right tools and libraries. By parsing the XML content and converting it to a dictionary-like structure, you can easily serialize and store the data as JSON. This conversion is essential for modern web applications and APIs that prefer JSON for data exchange.

Using libraries like xmltodict (Python) or xml2js (Node.js), you can handle XML-to-JSON conversion seamlessly, even with nested XML structures. With the provided examples, you can quickly implement this conversion and store the resulting JSON in your desired format, whether in a file or a database.