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/afp/fonts/IntegerKeyStore.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: IntegerKeyStore.java 1564017 2014-02-03 19:29:24Z vhennebert $ */

package org.apache.fop.afp.fonts;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

/**
 * A simple compact data structure to model a sparse array
 */
class IntegerKeyStore<T> {

    private static final int RANGE_BIT_SIZE = 8;

    private static final int RANGE_SIZE = 1 << RANGE_BIT_SIZE;

    private final Map<Integer, ArrayList<T>> arrays = new HashMap<Integer, ArrayList<T>>();

    /**
     *
     * @param index a positive integer
     * @param value value to store
     */
    public void put(Integer index, T value) {
        if (index < 0) {
            throw new IndexOutOfBoundsException();
        }
        int rangeKey = index >> RANGE_BIT_SIZE;
        int rangeIndex = index % RANGE_SIZE;
        ArrayList<T> range = arrays.get(rangeKey);
        if (range == null) {
            range = new ArrayList<T>(Collections.<T>nCopies(RANGE_SIZE, null));
            arrays.put(rangeKey, range);
        }
        range.set(rangeIndex, value);
    }

    /**
     *
     * @param index a positive integer
     * @return value the value associated with the index or null
     */
    public T get(Integer index) {
        if (index < 0) {
            throw new IndexOutOfBoundsException();
        }
        int rangeKey = index >> RANGE_BIT_SIZE;
        int rangeIndex = index % RANGE_SIZE;
        ArrayList<T> range = arrays.get(rangeKey);
        return range == null ? null : range.get(rangeIndex);
    }
}

⏎ org/apache/fop/afp/fonts/IntegerKeyStore.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)