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/pcl/fonts/PCLByteWriterUtil.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.pcl.fonts;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Arrays;

public final class PCLByteWriterUtil {

    private PCLByteWriterUtil() {
    }

    public static byte[] padBytes(byte[] in, int length) {
        return padBytes(in, length, 0);
    }

    public static byte[] padBytes(byte[] in, int length, int value) {
        byte[] out = new byte[length];
        for (int i = 0; i < length; i++) {
            if (i < in.length) {
                out[i] = in[i];
            } else {
                out[i] = (byte) value;
            }
        }
        return out;
    }

    public static byte[] signedInt(int s) {
        byte b1 = (byte) (s >> 8);
        byte b2 = (byte) s;
        return new byte[]{b1, b2};
    }

    public static byte signedByte(int s) {
        return (byte) s;
    }

    public static byte[] unsignedLongInt(int s) {
        return unsignedLongInt((long) s);
    }

    public static byte[] unsignedLongInt(long s) {
        byte b1 = (byte) ((s >> 24) & 0xff);
        byte b2 = (byte) ((s >> 16) & 0xff);
        byte b3 = (byte) ((s >> 8) & 0xff);
        byte b4 = (byte) (s & 0xff);
        return new byte[]{b1, b2, b3, b4};
    }

    public static byte[] unsignedInt(int s) {
        byte b1 = (byte) ((s >> 8) & 0xff);
        byte b2 = (byte) (s & 0xff);
        return new byte[]{b1, b2};
    }

    public static int unsignedByte(int b) {
        return (byte) b & 0xFF;
    }

    public static int maxPower2(int value) {
        int test = 2;
        while (test < value) {
            test *= 2;
        }
        return test;
    }

    public static int log(int x, int base) {
        return (int) (Math.log(x) / Math.log(base));
    }

    public static byte[] toByteArray(int[] s) {
        byte[] values = new byte[s.length];
        for (int i = 0; i < s.length; i++) {
            values[i] = (byte) s[i];
        }
        return values;
    }

    public static byte[] insertIntoArray(int index, byte[] insertTo, byte[] data) throws IOException {
        byte[] preBytes = Arrays.copyOf(insertTo, index);
        byte[] postBytes = Arrays.copyOfRange(insertTo, index, insertTo.length);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        baos.write(preBytes);
        baos.write(data);
        baos.write(postBytes);
        return baos.toByteArray();
    }

    public static byte[] updateDataAtLocation(byte[] data, byte[] update, int offset) {
        int count = 0;
        for (int i = offset; i < offset + update.length; i++) {
            data[i] = update[count++];
        }
        return data;
    }

    /**
     * Writes a PCL escape command to the output stream.
     * @param cmd the command (without the ESCAPE character)
     * @throws IOException In case of an I/O error
     */
    public static byte[] writeCommand(String cmd) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        baos.write(27); // ESC
        baos.write(cmd.getBytes("US-ASCII"));
        return baos.toByteArray();
    }
}

⏎ org/apache/fop/render/pcl/fonts/PCLByteWriterUtil.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)