Convert JSON to XML for Legacy System Integration

Why Legacy Systems Need XML

Enterprise software built before the JSON era relies on XML for structured data exchange. Common scenarios include:

• SOAP web services — older enterprise APIs that require XML-formatted requests.
• EDI systems — Electronic Data Interchange platforms that use XML wrappers.
• Banking and finance — ISO 20022 and SWIFT-compatible XML messages.
• Government interfaces — tax filings, customs declarations, and public records often mandate XML.
• Internal legacy tools — in-house systems built on XML-based configuration and data exchange.

Instead of writing custom XML serialization code, use the converter to transform JSON into the expected XML format instantly.

1. Mapping JSON Arrays to XML Elements

JSON arrays are the most common challenge when targeting XML. Consider order data from a modern e-commerce API:

{
  "order": {
    "orderId": "ORD-2026-001",
    "customer": {
      "name": "Acme Corp",
      "account": "AC-4412"
    },
    "products": [
      {"sku": "W-100", "qty": 5, "unitPrice": 24.99},
      {"sku": "W-200", "qty": 3, "unitPrice": 39.99},
      {"sku": "W-300", "qty": 10, "unitPrice": 14.99}
    ],
    "total": 374.80,
    "currency": "USD"
  }
}

Set the Root Element to OrderRequest and Array Item to product. The tool produces:

<?xml version="1.0" encoding="UTF-8"?>
<OrderRequest>
  <order>
    <orderId>ORD-2026-001</orderId>
    <customer>
      <name>Acme Corp</name>
      <account>AC-4412</account>
    </customer>
    <products>
      <product>
        <sku>W-100</sku>
        <qty>5</qty>
        <unitPrice>24.99</unitPrice>
      </product>
      <product>
        <sku>W-200</sku>
        <qty>3</qty>
        <unitPrice>39.99</unitPrice>
      </product>
      <product>
        <sku>W-300</sku>
        <qty>10</qty>
        <unitPrice>14.99</unitPrice>
      </product>
    </products>
    <total>374.8</total>
    <currency>USD</currency>
  </order>
</OrderRequest>

Each array item becomes a repeating XML element. The products array wrapper is preserved, and each product becomes a <product> child.

2. Data Type Handling in XML

The converter maps JSON types to XML text content:

• Strings → XML text content (e.g., <name>Alice</name>)
• Numbers → number-as-text (e.g., <price>24.99</price> — no quotes)
• Booleans → <active>true</active> or false
• Null → omitted from XML output (no empty element)
• Arrays → repeating elements with the same tag name
• Objects → nested child elements

The output is valid, well-formed XML that legacy systems can parse without issues.

3. Custom Root and Element Names

Enterprise systems often expect specific tag names. The converter lets you configure:

• Root Element — the top-level wrapper tag (default: root). Set it to match your target schema, like OrderRequest or InvoiceBatch.
• Array Item — the name for array child elements (default: item). Name it based on what the array contains, like product, lineItem, or record.

These settings are available in the converter's configuration panel. Changes update the XML preview in real time.

Best Practices for JSON to XML Enterprise Conversion

• Match expected element names. Check your target system's XML schema (XSD) and set the Root Element and Array Item names to match. Mismatched tag names are the most common integration failure.
• Avoid special characters in values. XML restricts certain characters (&, <, >) — the converter auto-escapes these, but it's better to clean the JSON first.
• Validate the XML output. Paste the result into the JSON Editor to check that the source JSON was clean before converting again.
• Handle encoding. The converter outputs UTF-8 encoded XML. Ensure your legacy system accepts UTF-8 (most modern systems do).
• Test with sample data first. Run a small test conversion before processing large batches to verify the element names and structure match your target system's requirements.

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Frequently Asked Questions