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

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

You can also browse Jackson Databind Source Code below:

⏎ com/fasterxml/jackson/databind/introspect/ClassIntrospector.java

package com.fasterxml.jackson.databind.introspect;

import com.fasterxml.jackson.databind.BeanDescription;
import com.fasterxml.jackson.databind.DeserializationConfig;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.SerializationConfig;
import com.fasterxml.jackson.databind.cfg.MapperConfig;

/**
 * Helper class used to introspect features of POJO value classes
 * used with Jackson. The main use is for finding out
 * POJO construction (creator) and value access (getters, setters)
 * methods and annotations that define configuration of using
 * those methods.
 */
public abstract class ClassIntrospector
{
    /*
    /**********************************************************
    /* Helper interfaces
    /**********************************************************
     */

    /**
     * Interface used for decoupling details of how mix-in annotation
     * definitions are accessed (via this interface), and how
     * they are stored (defined by classes that implement the interface)
     */
    public interface MixInResolver
    {
        /**
         * Method that will check if there are "mix-in" classes (with mix-in
         * annotations) for given class
         */
        public Class<?> findMixInClassFor(Class<?> cls);

        /**
         * Method called to create a new, non-shared copy, to be used by different
         * <code>ObjectMapper</code> instance, and one that should not be connected
         * to this instance, if resolver has mutable state.
         * If resolver is immutable may simply return `this`.
         * 
         * @since 2.6
         */
        public MixInResolver copy();
    }

    protected ClassIntrospector() { }

    /**
     * Method that may be needed when `copy()`ing `ObjectMapper` instances.
     *
     * @since 2.9.6
     */
    public abstract ClassIntrospector copy();

    /*
    /**********************************************************
    /* Public API: factory methods
    /**********************************************************
     */

    /**
     * Factory method that constructs an introspector that has all
     * information needed for serialization purposes.
     */
    public abstract BeanDescription forSerialization(SerializationConfig cfg,
    		JavaType type, MixInResolver r);

    /**
     * Factory method that constructs an introspector that has all
     * information needed for deserialization purposes.
     */
    public abstract BeanDescription forDeserialization(DeserializationConfig cfg,
    		JavaType type, MixInResolver r);

    /**
     * Factory method that constructs an introspector that has all
     * information needed for constructing deserializers that use
     * intermediate Builder objects.
     *
     * @since 2.12
     */
    public abstract BeanDescription forDeserializationWithBuilder(DeserializationConfig cfg,
            JavaType builderType, MixInResolver r, BeanDescription valueTypeDesc);

    /**
     * @deprecated Since 2.12 use overload that take value type description
     */
    @Deprecated
    public abstract BeanDescription forDeserializationWithBuilder(DeserializationConfig cfg,
            JavaType builderType, MixInResolver r);

    /**
     * Factory method that constructs an introspector that has
     * information necessary for creating instances of given
     * class ("creator"), as well as class annotations, but
     * no information on member methods
     */
    public abstract BeanDescription forCreation(DeserializationConfig cfg, JavaType type,
            MixInResolver r);

    /**
     * Factory method that constructs an introspector that only has
     * information regarding annotations class itself (or its supertypes) has,
     * but nothing on methods or constructors.
     */
    public abstract BeanDescription forClassAnnotations(MapperConfig<?> cfg, JavaType type,
            MixInResolver r);

    /**
     * Factory method that constructs an introspector that only has
     * information regarding annotations class itself has (but NOT including
     * its supertypes), but nothing on methods or constructors.
     */
    public abstract BeanDescription forDirectClassAnnotations(MapperConfig<?> cfg, JavaType type,
            MixInResolver r);
}

⏎ com/fasterxml/jackson/databind/introspect/ClassIntrospector.java

Or download all of them as a single archive file:

File name: jackson-databind-2.14.0-sources.jar
File size: 1187952 bytes
Release date: 2022-11-05
Download 

⇒ Jackson Annotations Source Code

⇐ Download and Install Jackson Binary Package

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library