kernel.jar is a component in iText Java library to provide low-level functionalities. iText Java library allows you to generate and manage PDF documents.

The Source Code files are provided together with the JAR file in the binary packge like iText7-Core-7.1.4.zip. You can download it at iText 7 Core Download site.

You can compile it to generate your JAR file, using kernel.pom as the build configuration file.

The source code of kernel-7.1.4.jar is provided below:

⏎ com/itextpdf/kernel/xmp/XMPDateTime.java

//Copyright (c) 2006, Adobe Systems Incorporated
//All rights reserved.
//
//        Redistribution and use in source and binary forms, with or without
//        modification, are permitted provided that the following conditions are met:
//        1. Redistributions of source code must retain the above copyright
//        notice, this list of conditions and the following disclaimer.
//        2. Redistributions in binary form must reproduce the above copyright
//        notice, this list of conditions and the following disclaimer in the
//        documentation and/or other materials provided with the distribution.
//        3. All advertising materials mentioning features or use of this software
//        must display the following acknowledgement:
//        This product includes software developed by the Adobe Systems Incorporated.
//        4. Neither the name of the Adobe Systems Incorporated nor the
//        names of its contributors may be used to endorse or promote products
//        derived from this software without specific prior written permission.
//
//        THIS SOFTWARE IS PROVIDED BY ADOBE SYSTEMS INCORPORATED ''AS IS'' AND ANY
//        EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
//        WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
//        DISCLAIMED. IN NO EVENT SHALL ADOBE SYSTEMS INCORPORATED BE LIABLE FOR ANY
//        DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
//        (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
//        LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
//        ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
//        (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
//        SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//        http://www.adobe.com/devnet/xmp/library/eula-xmp-library-java.html

package com.itextpdf.kernel.xmp;

import java.util.Calendar;
import java.util.TimeZone;


/**
 * The <code>XMPDateTime</code>-class represents a point in time up to a resolution of nano
 * seconds. Dates and time in the serialized XMP are ISO 8601 strings. There are utility functions
 * to convert to the ISO format, a <code>Calendar</code> or get the Timezone. The fields of
 * <code>XMPDateTime</code> are:
 * <ul>
 * <li> month - The month in the range 1..12.
 * <li> day - The day of the month in the range 1..31.
 * <li> minute - The minute in the range 0..59.
 * <li> hour - The time zone hour in the range 0..23.
 * <li> minute - The time zone minute in the range 0..59.
 * <li> nanoSecond - The nano seconds within a second. <em>Note:</em> if the XMPDateTime is
 * converted into a calendar, the resolution is reduced to milli seconds.
 * <li> timeZone - a <code>TimeZone</code>-object.
 * </ul>
 * DateTime values are occasionally used in cases with only a date or only a time component. A date
 * without a time has zeros for all the time fields. A time without a date has zeros for all date
 * fields (year, month, and day).
 */
public interface XMPDateTime extends Comparable
{
	/** @return Returns the year, can be negative. */
	int getYear();
	
	/** @param year Sets the year */
	void setYear(int year);

	/** @return Returns The month in the range 1..12. */
	int getMonth();

	/** @param month Sets the month 1..12 */
	void setMonth(int month);
	
	/** @return Returns the day of the month in the range 1..31. */
	int getDay();
	
	/** @param day Sets the day 1..31 */
	void setDay(int day);

	/** @return Returns hour - The hour in the range 0..23. */
	int getHour();

	/** @param hour Sets the hour in the range 0..23. */
	void setHour(int hour);
	
	/** @return Returns the minute in the range 0..59. */ 
	int getMinute();

	/** @param minute Sets the minute in the range 0..59. */
	void setMinute(int minute);
	
	/** @return Returns the second in the range 0..59. */
	int getSecond();

	/** @param second Sets the second in the range 0..59. */
	void setSecond(int second);
	
	/**
	 * @return Returns milli-, micro- and nano seconds.
	 * 		   Nanoseconds within a second, often left as zero?
	 */
	int getNanoSecond();

	/**
	 * @param nanoSecond Sets the milli-, micro- and nano seconds.
	 *		Granularity goes down to milli seconds. 		   
	 */
	void setNanoSecond(int nanoSecond);
	
	/** @return Returns the time zone. */
	TimeZone getTimeZone();

	/** @param tz a time zone to set */
	void setTimeZone(TimeZone tz);
	
	/**
	 * This flag is set either by parsing or by setting year, month or day. 
	 * @return Returns true if the XMPDateTime object has a date portion.
	 */
	boolean hasDate();
	
	/**
	 * This flag is set either by parsing or by setting hours, minutes, seconds or milliseconds. 
	 * @return Returns true if the XMPDateTime object has a time portion.
	 */
	boolean hasTime();
	
	/**
	 * This flag is set either by parsing or by setting hours, minutes, seconds or milliseconds. 
	 * @return Returns true if the XMPDateTime object has a defined timezone.
	 */
	boolean hasTimeZone();
	
	/** 
	 * @return Returns a <code>Calendar</code> (only with milli second precision). <br>
	 *  		<em>Note:</em> the dates before Oct 15th 1585 (which normally fall into validity of 
	 *  		the Julian calendar) are also rendered internally as Gregorian dates. 
	 */
	Calendar getCalendar();
	
	/**
	 * @return Returns the ISO 8601 string representation of the date and time.
	 */
	String getISO8601String();
}

⏎ com/itextpdf/kernel/xmp/XMPDateTime.java

Or download all of them as a single archive file:

File name: kernel-7.1.4-sources.jar
File size: 1201221 bytes
Release date: 2018-10-09
Download 

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