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

package org.apache.fop.pdf.xref;

import java.io.IOException;
import java.io.OutputStream;

import org.apache.fop.pdf.PDFArray;
import org.apache.fop.pdf.PDFDictionary;
import org.apache.fop.pdf.PDFDocument;
import org.apache.fop.pdf.PDFEncryption;
import org.apache.fop.pdf.PDFInfo;
import org.apache.fop.pdf.PDFRoot;
import org.apache.fop.pdf.PDFText;
import org.apache.fop.pdf.PDFWritable;

/**
 * A data class representing entries of the file trailer dictionary.
 */
public class TrailerDictionary {

    private final PDFDictionary dictionary;

    public TrailerDictionary(PDFDocument pdfDocument) {
        this.dictionary = new PDFDictionary();
        this.dictionary.setDocument(pdfDocument);
    }

    /** Sets the value of the Root entry. */
    public TrailerDictionary setRoot(PDFRoot root) {
        dictionary.put("/Root", root);
        return this;
    }

    /** Sets the value of the Info entry. */
    public TrailerDictionary setInfo(PDFInfo info) {
        dictionary.put("/Info", info);
        return this;
    }

    /** Sets the value of the Encrypt entry. */
    public TrailerDictionary setEncryption(PDFEncryption encryption) {
        dictionary.put("/Encrypt", encryption);
        return this;
    }

    /** Sets the value of the ID entry. */
    public TrailerDictionary setFileID(byte[] originalFileID, byte[] updatedFileID) {
        // TODO this is ugly! Used to circumvent the fact that the file ID will be
        // encrypted if directly stored as a byte array
        class FileID implements PDFWritable {

            private final byte[] fileID;

            FileID(byte[] id) {
                fileID = id;
            }

            public void outputInline(OutputStream out, StringBuilder textBuffer)
                    throws IOException {
                PDFDocument.flushTextBuffer(textBuffer, out);
                String hex = PDFText.toHex(fileID, true);
                byte[] encoded = hex.getBytes("US-ASCII");
                out.write(encoded);
            }

        }
        PDFArray fileID = new PDFArray(new FileID(originalFileID), new FileID(updatedFileID));
        dictionary.put("/ID", fileID);
        return this;
    }

    public PDFDictionary getDictionary() {
        return dictionary;
    }

}

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