What Is fop.jar? I got it from the fop-2.7-bin.zip.

fop.jar in fop-2.7-bin.zip is the JAR file for FOP 2.7, which is a print formatter driven by XSL formatting objects (XSL-FO). You can obtain fop.jar from the build folder of the fop-2.7-bin.zip file.

Below is the information about the fop.jar (2.2) file:

JAR File Size and Download Location:

JAR name: fop.jar, fop-2.7.jar
Target JDK version: 1.7
File name: fop.jar
File size: 4442817 bytes
Release date: 20-Jan-2022
Download: Apache FOP Website

Java source code files for fop.jar:

⏎ org/apache/fop/fonts/FontEventListener.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id: FontEventListener.java 1745490 2016-05-25 14:12:42Z ssteiner $ */

package org.apache.fop.fonts;

/**
 * Event listener interface for font-related events.
 */
public interface FontEventListener {

    /**
     * Notifies about a font being substituted as the requested one isn't available.
     * @param source the event source
     * @param requested the requested font triplet
     * @param effective the effective font triplet
     */
    void fontSubstituted(Object source, FontTriplet requested, FontTriplet effective);

    /**
     * An error occurred while loading a font for auto-detection.
     * @param source the event source
     * @param fontURL the font URL
     * @param e the original exception
     */
    void fontLoadingErrorAtAutoDetection(Object source, String fontURL, Exception e);

    /**
     * A glyph has been requested that is not available in the font.
     * @param source the event source
     * @param ch the character for which the glyph isn't available
     * @param fontName the name of the font
     */
    void glyphNotAvailable(Object source, char ch, String fontName);

    /**
     * An error occurred trying to find the font directory specified in the config file.
     * @param source the event source
     * @param dir the directory in the config file
     */
    void fontDirectoryNotFound(Object source, String dir);

    /**
     * The SVG text will be stroked as shapes.
     * @param source the event source
     * @param fontFamily the family name of the font that is being stroked
     */
    void svgTextStrokedAsShapes(Object source, String fontFamily);
}

⏎ org/apache/fop/fonts/FontEventListener.java

Or download all of them as a single archive file:

File name: fop-2.7-src.zip
File size: 3401312 bytes
Release date: 2022-01-20
Download 

⇒ "fop" Command in fop-2.7-bin.zip

⇐ What Is fop-2.7-bin.zip

⇑ Download and Installing of FOP 2.x

⇑⇑ FAQ for FOP (Formatting Object Processor)