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/ext/DOMSerializer.java

package com.fasterxml.jackson.databind.ext;

import java.io.IOException;
import java.io.StringWriter;

import javax.xml.XMLConstants;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Node;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;

@SuppressWarnings("serial")
public class DOMSerializer extends StdSerializer<Node>
{
    protected final TransformerFactory transformerFactory;

    public DOMSerializer() {
        super(Node.class);
        try {
            transformerFactory = TransformerFactory.newInstance();
            transformerFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
        } catch (Exception e) {
            throw new IllegalStateException("Could not instantiate `TransformerFactory`: "+e.getMessage(), e);
        }
    }

    @Override
    public void serialize(Node value, JsonGenerator g, SerializerProvider provider)
        throws IOException
    {
        try {
            Transformer transformer = transformerFactory.newTransformer();
            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
            transformer.setOutputProperty(OutputKeys.INDENT, "no");
            StreamResult result = new StreamResult(new StringWriter());
            transformer.transform(new DOMSource(value), result);
            g.writeString(result.getWriter().toString());
        } catch (TransformerConfigurationException e) {
            throw new IllegalStateException("Could not create XML Transformer for writing DOM `Node` value: "+e.getMessage(), e);
        } catch (TransformerException e) {
            provider.reportMappingProblem(e, "DOM `Node` value serialization failed: %s", e.getMessage());
        }
    }

    @Override
    public JsonNode getSchema(SerializerProvider provider, java.lang.reflect.Type typeHint) {
        // Well... it is serialized as String
        return createSchemaNode("string", true);
    }

    @Override
    public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint) throws JsonMappingException {
        if (visitor != null) visitor.expectAnyFormat(typeHint);
    }
}

⏎ com/fasterxml/jackson/databind/ext/DOMSerializer.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