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/fo/pagination/Title.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: Title.java 679326 2008-07-24 09:35:34Z vhennebert $ */

package org.apache.fop.fo.pagination;

// XML
import org.xml.sax.Locator;

import org.apache.fop.fo.FONode;
import org.apache.fop.fo.ValidationException;
import org.apache.fop.fo.flow.InlineLevel;

/**
 * Class modeling the <a href="http://www.w3.org/TR/xsl/#fo_title">
 * <code>fo:title</code></a> object.
 */
public class Title extends InlineLevel {
    // The value of properties relevant for fo:title.
    // See superclass InlineLevel
    // End of property values

    /**
     * @param parent FONode that is the parent of this object
     */
    public Title(FONode parent) {
        super(parent);
    }

    /**
     * {@inheritDoc} String, String)
     * <br>XSL/FOP: (#PCDATA|%inline;)*
     */
    protected void validateChildNode(Locator loc, String nsURI, String localName)
        throws ValidationException {
        if (FO_URI.equals(nsURI)) {
            if (!isInlineItem(nsURI, localName)) {
                invalidChildError(loc, nsURI, localName);
            }
        }
    }

    /** {@inheritDoc} */
    public String getLocalName() {
        return "title";
    }

    /**
     * {@inheritDoc}
     * @return {@link org.apache.fop.fo.Constants#FO_TITLE}
     */
    public int getNameId() {
        return FO_TITLE;
    }
}

⏎ org/apache/fop/fo/pagination/Title.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)