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/Version.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: Version.java 1305467 2012-03-26 17:39:20Z vhennebert $ */

package org.apache.fop.pdf;

/**
 * A version of PDF. Values are ordered such that compareTo() gives sensible
 * results (e.g., {@code V1_4.compareTo(V1_5) < 0}).
 */
public enum Version {
    /** PDF v1 */
    V1_0("1.0"),
    /** PDF v1.1 */
    V1_1("1.1"),
    /** PDF v1.2 */
    V1_2("1.2"),
    /** PDF v1.3 */
    V1_3("1.3"),
    /** PDF v1.4 */
    V1_4("1.4"),
    /** PDF v1.5 */
    V1_5("1.5"),
    /** PDF v1.6 */
    V1_6("1.6"),
    /** PDF v1.7 */
    V1_7("1.7");

    private String version;

    private Version(String version) {
        this.version = version;
    }

    /**
     * Given the PDF version as a String, returns the corresponding enumerated type. The
     * String should be in the format "1.x" for PDF v1.x.
     *
     * @param version a version number
     * @return the corresponding Version instance
     * @throws IllegalArgumentException if the argument does not correspond to any
     * existing PDF version
     */
    public static Version getValueOf(String version) {
        for (Version pdfVersion : Version.values()) {
            if (pdfVersion.toString().equals(version)) {
                return pdfVersion;
            }
        }
        throw new IllegalArgumentException("Invalid PDF version given: " + version);
    }

    @Override
    public String toString() {
        return version;
    }
}

⏎ org/apache/fop/pdf/Version.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)