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-2.14.0-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Annotations Source Code below:

⏎ com/fasterxml/jackson/annotation/SimpleObjectIdResolver.java

package com.fasterxml.jackson.annotation;

import java.util.HashMap;
import java.util.Map;

import com.fasterxml.jackson.annotation.ObjectIdGenerator.IdKey;

/**
 * Simple implementation of {@link ObjectIdResolver}
 * 
 * @author Pascal Gélinas
 */
public class SimpleObjectIdResolver implements ObjectIdResolver {
    protected Map<IdKey,Object> _items;

    public SimpleObjectIdResolver() { }

    @Override
    public void bindItem(IdKey id, Object ob)
    {
        if (_items == null) {
            _items = new HashMap<ObjectIdGenerator.IdKey,Object>();
        } else {
            Object old = _items.get(id);
            if (old != null) {
                // 11-Nov-2020, tatu: As per [annotations#180] allow duplicate calls:
                if (old == ob) {
                    return;
                }
                throw new IllegalStateException("Already had POJO for id (" + id.key.getClass().getName() + ") [" + id
                        + "]");
            }
        }
        _items.put(id, ob);
    }

    @Override
    public Object resolveId(IdKey id) {
        return (_items == null) ? null : _items.get(id);
    }

    @Override
    public boolean canUseFor(ObjectIdResolver resolverType) {
        return resolverType.getClass() == getClass();
    }

    @Override
    public ObjectIdResolver newForDeserialization(Object context) {
        // 19-Dec-2014, tatu: Important: must re-create without existing mapping; otherwise bindings leak
        //    (and worse, cause unnecessary memory retention)
        return new SimpleObjectIdResolver();
    }
}

⏎ com/fasterxml/jackson/annotation/SimpleObjectIdResolver.java

Or download all of them as a single archive file:

File name: jackson-annotations-2.14.0-sources.jar
File size: 80402 bytes
Release date: 2022-11-05
Download 

⇒ Jackson Dataformat Extensions

⇐ Jackson Data Binding Source Code

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library