Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

Jackson Core Source Code files are provided in the source packge (jackson-core-2.14.0-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Core Source Code below:

⏎ com/fasterxml/jackson/core/JsonEncoding.java

/* Jackson JSON-processor.
 *
 * Copyright (c) 2007- Tatu Saloranta, tatu.saloranta@iki.fi
 */

package com.fasterxml.jackson.core;

/**
 * Enumeration that defines legal encodings that can be used
 * for JSON content, based on list of allowed encodings from
 * <a href="http://www.ietf.org/rfc/rfc4627.txt">JSON specification</a>.
 *<p>
 * Note: if application want to explicitly disregard Encoding
 * limitations (to read in JSON encoded using an encoding not
 * listed as allowed), they can use {@link java.io.Reader} /
 * {@link java.io.Writer} instances as input
 */
public enum JsonEncoding {
    UTF8("UTF-8", false, 8), // N/A for big-endian, really
        UTF16_BE("UTF-16BE", true, 16),
        UTF16_LE("UTF-16LE", false, 16),
        UTF32_BE("UTF-32BE", true, 32),
        UTF32_LE("UTF-32LE", false, 32)
        ;

    private final String _javaName;

    private final boolean _bigEndian;

    private final int _bits;
    
    JsonEncoding(String javaName, boolean bigEndian, int bits)
    {
        _javaName = javaName;
        _bigEndian = bigEndian;
        _bits = bits;
    }

    /**
     * Method for accessing encoding name that JDK will support.
     *
     * @return Matching encoding name that JDK will support.
     */
    public String getJavaName() { return _javaName; }

    /**
     * Whether encoding is big-endian (if encoding supports such
     * notion). If no such distinction is made (as is the case for
     * {@link #UTF8}), return value is undefined.
     *
     * @return True for big-endian encodings; false for little-endian
     *   (or if not applicable)
     */
    public boolean isBigEndian() { return _bigEndian; }

    public int bits() { return _bits; }
}

⏎ com/fasterxml/jackson/core/JsonEncoding.java

Or download all of them as a single archive file:

File name: jackson-core-2.14.0-sources.jar
File size: 497693 bytes
Release date: 2022-11-05
Download 

⇒ Download and Install Jackson Binary Package

⇐ What Is Jackson

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library