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/deser/XmlDeserializationContext.java

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

import java.io.IOException;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.deser.DefaultDeserializationContext;
import com.fasterxml.jackson.databind.deser.DeserializerCache;
import com.fasterxml.jackson.databind.deser.DeserializerFactory;

/**
 * XML-specific {@link DeserializationContext} needed to override certain
 * handlers.
 *
 * @since 2.12
 */
public class XmlDeserializationContext
    extends DefaultDeserializationContext
{
    private static final long serialVersionUID = 1L;

    /*
    /**********************************************************
    /* Life-cycle methods
    /**********************************************************
     */

    /**
     * Default constructor for a blueprint object, which will use the standard
     * {@link DeserializerCache}, given factory.
     */
    public XmlDeserializationContext(DeserializerFactory df) {
        super(df, null);
    }

    private XmlDeserializationContext(XmlDeserializationContext src,
            DeserializationConfig config, JsonParser p, InjectableValues values) {
        super(src, config, p, values);
    }

    private XmlDeserializationContext(XmlDeserializationContext src) { super(src); }

    private XmlDeserializationContext(XmlDeserializationContext src, DeserializerFactory factory) {
        super(src, factory);
    }

    private XmlDeserializationContext(XmlDeserializationContext src, DeserializationConfig config) {
        super(src, config);
    }

    @Override
    public XmlDeserializationContext copy() {
        return new XmlDeserializationContext(this);
    }

    @Override
    public DefaultDeserializationContext createInstance(DeserializationConfig config,
            JsonParser p, InjectableValues values) {
        return new XmlDeserializationContext(this, config, p, values);
    }

    @Override
    public DefaultDeserializationContext createDummyInstance(DeserializationConfig config) {
        // need to be careful to create non-blue-print instance
        return new XmlDeserializationContext(this, config);
    }

    @Override
    public DefaultDeserializationContext with(DeserializerFactory factory) {
        return new XmlDeserializationContext(this, factory);
    }

    /*
    /**********************************************************
    /* Overrides we need
    /**********************************************************
     */

    @Override // since 2.12
    public Object readRootValue(JsonParser p, JavaType valueType,
            JsonDeserializer<Object> deser, Object valueToUpdate)
        throws IOException
    {
        // 18-Sep-2021, tatu: Complicated mess; with 2.12, had [dataformat-xml#374]
        //    to disable handling. With 2.13, via [dataformat-xml#485] undid this change
        if (_config.useRootWrapping()) {
            return _unwrapAndDeserialize(p, valueType, deser, valueToUpdate);
        }
        if (valueToUpdate == null) {
            return deser.deserialize(p, this);
        }
        return deser.deserialize(p, this, valueToUpdate);
    }

    // To support case where XML element has attributes as well as CDATA, need
    // to "extract" scalar value (CDATA), after the fact
    @Override // since 2.12
    public String extractScalarFromObject(JsonParser p, JsonDeserializer<?> deser,
            Class<?> scalarType)
        throws IOException
    {
        // Only called on START_OBJECT, should not need to check, but JsonParser we
        // get may or may not be `FromXmlParser` so traverse using regular means
        String text = "";

        while (p.nextToken() == JsonToken.FIELD_NAME) {
            // Couple of ways to find "real" textual content. One is to look for
            // "XmlText"... but for that would need to know configuration. Alternatively
            // could hold on to last text seen -- but this might be last attribute, for
            // empty element. So for now let's simply hard-code check for empty String
            // as marker and hope for best
            final String propName = p.currentName();
            JsonToken t = p.nextToken();
            if (t == JsonToken.VALUE_STRING) {
                if (propName.equals("")) {
                    text = p.getText();
                }
            } else {
                p.skipChildren();
            }
        }
        return text;
    }

}

⏎ com/fasterxml/jackson/dataformat/xml/deser/XmlDeserializationContext.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