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/util/RootNameLookup.java

package com.fasterxml.jackson.databind.util;

import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.cfg.MapperConfig;
import com.fasterxml.jackson.databind.introspect.AnnotatedClass;
import com.fasterxml.jackson.databind.type.ClassKey;

/**
 * Helper class for caching resolved root names.
 */
public class RootNameLookup implements java.io.Serializable
{
    private static final long serialVersionUID = 1L;

    /**
     * For efficient operation, let's try to minimize number of times we
     * need to introspect root element name to use.
     */
    protected transient LRUMap<ClassKey,PropertyName> _rootNames;

    public RootNameLookup() {
        _rootNames = new LRUMap<ClassKey,PropertyName>(20, 200);
   }

    public PropertyName findRootName(JavaType rootType, MapperConfig<?> config) {
        return findRootName(rootType.getRawClass(), config);
    }

    public PropertyName findRootName(Class<?> rootType, MapperConfig<?> config)
    {
        ClassKey key = new ClassKey(rootType);
        PropertyName name = _rootNames.get(key); 
        if (name != null) {
            return name;
        }
        BeanDescription beanDesc = config.introspectClassAnnotations(rootType);
        AnnotationIntrospector intr = config.getAnnotationIntrospector();
        AnnotatedClass ac = beanDesc.getClassInfo();
        name = intr.findRootName(ac);
        // No answer so far? Let's just default to using simple class name
        if (name == null || !name.hasSimpleName()) {
            // Should we strip out enclosing class tho? For now, nope:
            name = PropertyName.construct(rootType.getSimpleName());
        }
        _rootNames.put(key, name);
        return name;
    }

    /*
    /**********************************************************
    /* Serializable overrides
    /**********************************************************
     */

    /**
     * Need to override to reproduce cache object via constructor, instead
     * of serialize/deserialize (since we do NOT want to retain cached data)
     */
    protected Object readResolve() {
        return new RootNameLookup();
    }
}

⏎ com/fasterxml/jackson/databind/util/RootNameLookup.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