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/pdf/CompressedObject.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: CompressedObject.java 1661887 2015-02-24 11:23:44Z ssteiner $ */

package org.apache.fop.pdf;

import java.io.IOException;
import java.io.OutputStream;

/**
 * Represents a PDF object that may appear in an object stream. An object stream is a PDF
 * stream whose content is a sequence of PDF objects. See Section 3.4.6 of the PDF 1.5
 * Reference.
 */
interface CompressedObject {

    /**
     * Returns the object number of this indirect object. Note that a compressed object
     * must have a generation number of 0.
     *
     * @return the object number.
     */
    PDFObjectNumber getObjectNumber();

    /**
     * Outputs this object's content into the given stream.
     *
     * @param outputStream a stream, likely to be provided by the containing object stream
     * @return the number of bytes written to the stream
     * @throws IOException
     */
    int output(OutputStream outputStream) throws IOException;

}

⏎ org/apache/fop/pdf/CompressedObject.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)