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

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

You can also browse Jackson Core Source Code below:

⏎ com/fasterxml/jackson/core/Versioned.java

/* Jackson JSON-processor.
 *
 * Copyright (c) 2007- Tatu Saloranta, tatu.saloranta@iki.fi
 */

package com.fasterxml.jackson.core;

/**
 * Interface that those Jackson components that are explicitly versioned will implement.
 * Intention is to allow both plug-in components (custom extensions) and applications and
 * frameworks that use Jackson to detect exact version of Jackson in use.
 * This may be useful for example for ensuring that proper Jackson version is deployed
 * (beyond mechanisms that deployment system may have), as well as for possible
 * workarounds.
 */
public interface Versioned {
    /**
     * Method called to detect version of the component that implements this interface;
     * returned version should never be null, but may return specific "not available"
     * instance (see {@link Version} for details).
     *
     * @return Version of the component
     */
    Version version();
}

⏎ com/fasterxml/jackson/core/Versioned.java

Or download all of them as a single archive file:

File name: jackson-core-2.14.0-sources.jar
File size: 497693 bytes
Release date: 2022-11-05
Download 

⇒ Download and Install Jackson Binary Package

⇐ What Is Jackson

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library