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/annotation/JacksonXmlElementWrapper.java

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

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Annotation that is similar to JAXB {@code jakarta.xml.bind.annotation.XmlElementWrapper},
 * to indicate wrapper element to use (if any) for Collection types (arrays,
 * {@link java.util.Collection}). If defined, a separate container (wrapper) element
 * is used; if not, entries are written without wrapping.
 */
@Target({ElementType.ANNOTATION_TYPE, ElementType.FIELD, ElementType.METHOD,
    // @since 2.12 also allowed on (constructor) parameter
    ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
public @interface JacksonXmlElementWrapper
{
    /**
     * Marker value (empty String) that denotes that the underlying property
     * name should also be used as the wrapper name, effectively "doubling"
     * start and end elements.
     * 
     * @since 2.1
     */
    public final static String USE_PROPERTY_NAME = "";
    
    String namespace() default USE_PROPERTY_NAME;
    String localName() default USE_PROPERTY_NAME;

    /**
     * Optional property that can be used to explicitly disable wrapping,
     * usually via mix-ins, or when using <code>AnnotationIntrospector</code>
     * pairs.
     * 
     * @since 2.1
     */
    boolean useWrapping() default true;
}

⏎ com/fasterxml/jackson/dataformat/xml/annotation/JacksonXmlElementWrapper.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