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/ser/std/DateSerializer.java

package com.fasterxml.jackson.databind.ser.std;

import java.io.IOException;
import java.text.DateFormat;
import java.util.*;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;

/**
 * For efficiency, we will serialize Dates as longs, instead of
 * potentially more readable Strings.
 */
@JacksonStdImpl
@SuppressWarnings("serial")
public class DateSerializer
    extends DateTimeSerializerBase<Date>
{
    /**
     * Default instance that is used when no contextual configuration
     * is needed.
     */
    public static final DateSerializer instance = new DateSerializer();
    
    public DateSerializer() {
        this(null, null);
    }
        
    public DateSerializer(Boolean useTimestamp, DateFormat customFormat) {
        super(Date.class, useTimestamp, customFormat);
    }

    @Override
    public DateSerializer withFormat(Boolean timestamp, DateFormat customFormat) {
        return new DateSerializer(timestamp, customFormat);
    }

    @Override
    protected long _timestamp(Date value) {
        return (value == null) ? 0L : value.getTime();
    }

    @Override
    public void serialize(Date value, JsonGenerator g, SerializerProvider provider) throws IOException
    {
        if (_asTimestamp(provider)) {
            g.writeNumber(_timestamp(value));
            return;
        }
        _serializeAsString(value, g, provider);
    }
}

⏎ com/fasterxml/jackson/databind/ser/std/DateSerializer.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