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/CustomFontCollection.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: CustomFontCollection.java 1761020 2016-09-16 11:17:35Z ssteiner $ */

package org.apache.fop.fonts;

import java.util.List;

import org.apache.fop.apps.io.InternalResourceResolver;

/**
 * Sets up a set of custom (embedded) fonts
 */
public class CustomFontCollection implements FontCollection {

    private final List<EmbedFontInfo> embedFontInfoList;
    private final InternalResourceResolver uriResolver;
    private final boolean useComplexScripts;

    /**
     * Main constructor.
     * @param fontResolver a font resolver
     * @param customFonts the list of custom fonts
     * @param useComplexScriptFeatures true if complex script features enabled
     */
    public CustomFontCollection(InternalResourceResolver fontResolver,
            List<EmbedFontInfo> customFonts, boolean useComplexScriptFeatures) {
        this.uriResolver = fontResolver;
        this.embedFontInfoList = customFonts;
        this.useComplexScripts = useComplexScriptFeatures;
    }

    /** {@inheritDoc} */
    public int setup(int num, FontInfo fontInfo) {
        if (embedFontInfoList == null) {
            return num; //No fonts to process
        }

        String internalName = null;

        for (EmbedFontInfo embedFontInfo : embedFontInfoList) {
            internalName = "F" + num;
            num++;

            LazyFont font = new LazyFont(embedFontInfo, this.uriResolver, useComplexScripts);
            fontInfo.addMetrics(internalName, font);

            List<FontTriplet> triplets = embedFontInfo.getFontTriplets();
            for (FontTriplet triplet : triplets) {
                fontInfo.addFontProperties(internalName, triplet);
            }
        }
        return num;
    }
}

⏎ org/apache/fop/fonts/CustomFontCollection.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)