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

package org.apache.fop.pdf.xref;

import java.io.IOException;
import java.io.OutputStream;
import java.util.List;

import org.apache.fop.pdf.PDFDictionary;
import org.apache.fop.pdf.PDFDocument;

/**
 * A cross-reference table, as described in Section 3.4.3 of the PDF 1.5 Reference.
 */
public class CrossReferenceTable extends CrossReferenceObject {

    private final List<Long> objectReferences;

    private final StringBuilder pdf = new StringBuilder(256);

    private int last;
    private int first;
    private int size;

    public CrossReferenceTable(TrailerDictionary trailerDictionary, long startxref,
            List<Long> location, int first, int last, int size) {
        super(trailerDictionary, startxref);
        this.objectReferences = location;
        this.first = first;
        this.last = last;
        this.size = size;
    }

    public void output(OutputStream stream) throws IOException {
        outputXref();
        writeTrailer(stream);
    }

    private void outputXref() throws IOException {
        if (first == 0) {
            pdf.append("xref\n0 ");
            pdf.append(last + 1);
            pdf.append("\n0000000000 65535 f \n");
        } else {
            pdf.append("xref\n" + (first + 1) + " ");
            pdf.append(last + "\n");
        }
        for (int i = first; i < first + last; i++) {
            Long objectReference = objectReferences.get(i);
            assert objectReference != null;
            final String padding = "0000000000";
            String s = String.valueOf(objectReference);
            if (s.length() > 10) {
                throw new IOException("PDF file too large."
                        + " PDF 1.4 cannot grow beyond approx. 9.3GB.");
            }
            String loc = padding.substring(s.length()) + s;
            pdf.append(loc).append(" 00000 n \n");
        }
    }

    private void writeTrailer(OutputStream stream) throws IOException {
        pdf.append("trailer\n");
        stream.write(PDFDocument.encode(pdf.toString()));
        PDFDictionary dictionary = trailerDictionary.getDictionary();
        dictionary.put("/Size", size + 1);
        dictionary.output(stream);
    }

}

⏎ org/apache/fop/pdf/xref/CrossReferenceTable.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)