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/node/ValueNode.java

package com.fasterxml.jackson.databind.node;

import java.io.IOException;
import java.util.List;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.type.WritableTypeId;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;

/**
 * This intermediate base class is used for all leaf nodes, that is,
 * all non-container (array or object) nodes, except for the
 * "missing node".
 */
public abstract class ValueNode
    extends BaseJsonNode
{
    private static final long serialVersionUID = 1L;

    protected ValueNode() { }

    @Override
    protected JsonNode _at(JsonPointer ptr) {
        // 02-Jan-2020, tatu: As per [databind#3005] must return `null` and NOT
        //    "missing node"
        return null;
    }

    /**
     * All current value nodes are immutable, so we can just return
     * them as is.
     */
    @SuppressWarnings("unchecked")
    @Override
    public <T extends JsonNode> T deepCopy() { return (T) this; }
    
    @Override public abstract JsonToken asToken();

    @Override
    public void serializeWithType(JsonGenerator g, SerializerProvider provider,
            TypeSerializer typeSer)
        throws IOException
    {
        WritableTypeId typeIdDef = typeSer.writeTypePrefix(g,
                typeSer.typeId(this, asToken()));
        serialize(g, provider);
        typeSer.writeTypeSuffix(g, typeIdDef);
    }

    /*
    /**********************************************************************
    /* Basic property access
    /**********************************************************************
     */

    @Override
    public boolean isEmpty() { return true; }
    
    /*
    /**********************************************************************
    /* Navigation methods
    /**********************************************************************
     */

    @Override
    public final JsonNode get(int index) { return null; }

    @Override
    public final JsonNode path(int index) { return MissingNode.getInstance(); }

    @Override
    public final boolean has(int index) { return false; }

    @Override
    public final boolean hasNonNull(int index) { return false; }

    @Override
    public final JsonNode get(String fieldName) { return null; }

    @Override
    public final JsonNode path(String fieldName) { return MissingNode.getInstance(); }

    @Override
    public final boolean has(String fieldName) { return false; }

    @Override
    public final boolean hasNonNull(String fieldName) { return false; }

    /*
     **********************************************************************
     * Find methods: all "leaf" nodes return the same for these
     **********************************************************************
     */

    @Override
    public final JsonNode findValue(String fieldName) {
        return null;
    }

    // note: co-variant return type
    @Override
    public final ObjectNode findParent(String fieldName) {
        return null;
    }

    @Override
    public final List<JsonNode> findValues(String fieldName, List<JsonNode> foundSoFar) {
        return foundSoFar;
    }

    @Override
    public final List<String> findValuesAsText(String fieldName, List<String> foundSoFar) {
        return foundSoFar;
    }

    @Override
    public final List<JsonNode> findParents(String fieldName, List<JsonNode> foundSoFar) {
        return foundSoFar;
    }
}

⏎ com/fasterxml/jackson/databind/node/ValueNode.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