How to Compare Two XML Files with the Same Namespace but Different Prefixes Using Java and XMLUnit

How can I compare two XML files that share the same namespace but utilize different prefixes in Java using the XMLUnit library?

<a href="#">Java XMLUnit Comparison Example</a>

Comparing two XML documents that share the same namespace but have different prefixes can be challenging due to the structure of XML. Fortunately, the XMLUnit library in Java provides robust tools to perform such comparisons effectively.

import org.xmlunit.builder.Input;
import org.xmlunit.diff.Diff;
import org.xmlunit.diff.Difference;

public class CompareXml {
    public static void main(String[] args) {
        String xml1 = "<ns:root xmlns:ns='http://example.com/ns'><ns:child>Content</ns:child></ns:root>";
        String xml2 = "<other:root xmlns:other='http://example.com/ns'><other:child>Content</other:child></other:root>";

        Diff diff = DiffBuilder.compare(Input.fromString(xml1))
            .withTest(Input.fromString(xml2))
            .ignoreWhitespace() // Ignore whitespaces
            .checkForSimilar() // Check for similar structure
            .build();

        if (diff.hasDifferences()) {
            for (Difference difference : diff.getDifferences()) {
                System.out.println(difference);
            }
        } else {
            System.out.println("XMLs are similar.");
        }
    }
}

Causes

• Different XML prefixes despite being in the same namespace can cause equality checks to fail.
• Whitespace and formatting differences may affect the comparison results.

Solutions

• Use XMLUnit's `ComparisonBuilder` to ignore namespace prefixes while comparing.
• Configure XMLUnit to normalize the XML structures before the comparison.

Mistake: Ignoring namespace during XML comparison.

Solution: Use XMLUnit's API to specify that the namespaces should be ignored.

Mistake: Not accounting for formatting or whitespace differences.

Solution: Include options in XMLUnit to ignore those differences.