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

Jackson Annotations Source Code files are provided in the source packge (jackson-annotations-2.12.4-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Annotations Source Code below:

⏎ com/fasterxml/jackson/databind/InjectableValues.java

package com.fasterxml.jackson.databind;

import java.util.*;

import com.fasterxml.jackson.databind.util.ClassUtil;

/**
 * Abstract class that defines API for objects that provide value to
 * "inject" during deserialization. An instance of this object
 */
public abstract class InjectableValues
{
    /**
     * Method called to find value identified by id <code>valueId</code> to
     * inject as value of specified property during deserialization, passing
     * POJO instance in which value will be injected if it is available
     * (will be available when injected via field or setter; not available
     * when injected via constructor or factory method argument).
     * 
     * @param valueId Object that identifies value to inject; may be a simple
     *   name or more complex identifier object, whatever provider needs
     * @param ctxt Deserialization context
     * @param forProperty Bean property in which value is to be injected
     * @param beanInstance Bean instance that contains property to inject,
     *    if available; null if bean has not yet been constructed.
     */
    public abstract Object findInjectableValue(Object valueId, DeserializationContext ctxt,
            BeanProperty forProperty, Object beanInstance) throws JsonMappingException;

    /*
    /**********************************************************
    /* Standard implementation
    /**********************************************************
     */

    /**
     * Simple standard implementation which uses a simple Map to
     * store values to inject, identified by simple String keys.
     */
    public static class Std
        extends InjectableValues
        implements java.io.Serializable
    {
        private static final long serialVersionUID = 1L;

        protected final Map<String,Object> _values;
        
        public Std() {
            this(new HashMap<String,Object>());
        }

        public Std(Map<String,Object> values) {
            _values = values;
        }

        public Std addValue(String key, Object value) {
            _values.put(key, value);
            return this;
        }

        public Std addValue(Class<?> classKey, Object value) {
            _values.put(classKey.getName(), value);
            return this;
        }
        
        @Override
        public Object findInjectableValue(Object valueId, DeserializationContext ctxt,
                BeanProperty forProperty, Object beanInstance) throws JsonMappingException
        {
            if (!(valueId instanceof String)) {
                ctxt.reportBadDefinition(ClassUtil.classOf(valueId),
                        String.format(
                        "Unrecognized inject value id type (%s), expecting String",
                        ClassUtil.classNameOf(valueId)));
            }
            String key = (String) valueId;
            Object ob = _values.get(key);
            if (ob == null && !_values.containsKey(key)) {
                throw new IllegalArgumentException("No injectable id with value '"+key+"' found (for property '"+forProperty.getName()+"')");
            }
            return ob;
        }
    }
}

⏎ com/fasterxml/jackson/databind/InjectableValues.java

 

⇒ Jackson Dataformat Extensions

⇐ Jackson Data Binding Source Code

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library