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/render/pdf/extensions/PDFArrayElement.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.
 */

/* $Id$ */

package org.apache.fop.render.pdf.extensions;

import org.xml.sax.Attributes;
import org.xml.sax.Locator;

import org.apache.fop.apps.FOPException;
import org.apache.fop.fo.FONode;
import org.apache.fop.fo.PropertyList;

// CSOFF: LineLengthCheck

/**
 * Extension element for pdf:array.
 */
public class PDFArrayElement extends PDFCollectionEntryElement {

    private PDFArrayExtension extension;

    /**
     * Main constructor
     * @param parent parent FO node
     */
    PDFArrayElement(FONode parent) {
        super(parent, PDFObjectType.Array, new PDFArrayExtension());
    }

    public PDFArrayExtension getArrayExtension() {
        PDFCollectionEntryExtension extension = getExtension();
        assert (extension instanceof PDFArrayExtension);
        return (PDFArrayExtension) extension;
    }

    @Override
    public void processNode(String elementName, Locator locator, Attributes attlist, PropertyList propertyList) throws FOPException {
        super.processNode(elementName, locator, attlist, propertyList);
    }

    @Override
    public void startOfNode() throws FOPException {
        super.startOfNode();
    }

    @Override
    protected void addChildNode(FONode child) throws FOPException {
        PDFArrayExtension extension = getArrayExtension();
        if (child instanceof PDFCollectionEntryElement) {
            PDFCollectionEntryExtension entry = ((PDFCollectionEntryElement) child).getExtension();
            if (entry.getKey() == null) {
                extension.addEntry(entry);
            }
        }
    }

    @Override
    public void endOfNode() throws FOPException {
        super.endOfNode();
    }

    @Override
    public String getLocalName() {
        return PDFObjectType.Array.elementName();
    }

}

⏎ org/apache/fop/render/pdf/extensions/PDFArrayElement.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)