Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

Jackson also allows you to parse or generate XML messages with the Jackson Dataformat XML Extension.

Jackson Dataformat XML Source Code files are provided in the source packge (jackson-dataformat-xml-2.14.0-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Dataformat XML Source Code below:

⏎ com/fasterxml/jackson/dataformat/xml/util/CaseInsensitiveNameSet.java

package com.fasterxml.jackson.dataformat.xml.util;

import java.util.*;

/**
 * Helper class for matching element wrappers, possibly in case-insensitive
 * manner.
 *
 * @since 2.12
 */
public final class CaseInsensitiveNameSet extends AbstractSet<String>
{
    private final Set<String> _namesToMatch;

    private CaseInsensitiveNameSet(Set<String> namesToMatch) {
        _namesToMatch = namesToMatch;
    }

    public static CaseInsensitiveNameSet construct(Set<String> names0) {
        Set<String> namesToMatch = new HashSet<String>(names0);
        for (String name : names0) {
            namesToMatch.add(name.toLowerCase());
        }
        return new CaseInsensitiveNameSet(namesToMatch);
    }

    @Override
    public boolean contains(Object key0) {
        final String key = (String) key0;
        if (_namesToMatch.contains(key)) {
            return true;
        }
        final String lc = key.toLowerCase();
        return (lc != key) && _namesToMatch.contains(lc);
    }

    @Override
    public Iterator<String> iterator() {
        return _namesToMatch.iterator();
    }

    @Override
    public int size() {
        return _namesToMatch.size();
    }
}

⏎ com/fasterxml/jackson/dataformat/xml/util/CaseInsensitiveNameSet.java

Or download all of them as a single archive file:

File name: jackson-dataformat-xml-2.14.0-sources.jar
File size: 98015 bytes
Release date: 2022-11-05
Download 

⇒ Download Jackson Dataformat Binary Packages

⇐ Jackson Dataformat Extensions

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library