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/layoutmgr/Adjustment.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: Adjustment.java 1805173 2017-08-16 10:50:04Z ssteiner $ */

package org.apache.fop.layoutmgr;

/**
 * @see KnuthGlue
 * http://www.leverkruid.eu/GKPLinebreaking/elements.html
 */
public final class Adjustment {

    /**
     * Adjustment class: no adjustment.
     */
    public static final Adjustment NO_ADJUSTMENT = new Adjustment("none");

    /**
     * Adjustment class: adjustment for space-before.
     */
    public static final Adjustment SPACE_BEFORE_ADJUSTMENT = new Adjustment("space-before");

    /**
     * Adjustment class: adjustment for space-after.
     */
    public static final Adjustment SPACE_AFTER_ADJUSTMENT = new Adjustment("space-after");

    /**
     * Adjustment class: adjustment for number of lines.
     */
    public static final Adjustment LINE_NUMBER_ADJUSTMENT = new Adjustment("line-number");

    /**
     * Adjustment class: adjustment for line height.
     */
    public static final Adjustment LINE_HEIGHT_ADJUSTMENT = new Adjustment("line-height");

    private final String name;

    private Adjustment(String name) {
        this.name = name;
    }

    /** {@inheritDoc} */
    public boolean equals(Object obj) {
        return this == obj;
    }

    /** {@inheritDoc} */
    public int hashCode() {
        return super.hashCode();
    }

    /** {@inheritDoc} */
    public String toString() {
        return name;
    }
}

⏎ org/apache/fop/layoutmgr/Adjustment.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)