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/configuration/NullConfiguration.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: Accessibility.java 1343632 2012-05-29 09:48:03Z vhennebert $ */
package org.apache.fop.configuration;

final class NullConfiguration implements Configuration {

    static final NullConfiguration INSTANCE = new NullConfiguration();

    private NullConfiguration() {

    }

    @Override
    public Configuration getChild(String key) {
        return INSTANCE;
    }

    @Override
    public Configuration getChild(String key, boolean required) {
        return INSTANCE;
    }

    @Override
    public Configuration[] getChildren(String key) {
        return new Configuration[0];
    }

    @Override
    public String[] getAttributeNames() {
        return new String[0];
    }

    @Override
    public String getAttribute(String key) throws ConfigurationException {
        return "";
    }

    @Override
    public String getAttribute(String key, String defaultValue) {
        return defaultValue;
    }

    @Override
    public boolean getAttributeAsBoolean(String key, boolean defaultValue) {
        return defaultValue;
    }

    @Override
    public float getAttributeAsFloat(String key) throws ConfigurationException {
        return 0;
    }

    @Override
    public float getAttributeAsFloat(String key, float defaultValue) {
        return defaultValue;
    }

    @Override
    public int getAttributeAsInteger(String key, int defaultValue) {
        return defaultValue;
    }

    @Override
    public String getValue() throws ConfigurationException {
        // return null;
        throw new ConfigurationException("missing value");
    }

    @Override
    public String getValue(String defaultValue) {
        return defaultValue;
    }

    @Override
    public boolean getValueAsBoolean() throws ConfigurationException {
        return false;
    }

    @Override
    public boolean getValueAsBoolean(boolean defaultValue) {
        return defaultValue;
    }

    @Override
    public int getValueAsInteger() throws ConfigurationException {
        return 0;
    }

    @Override
    public int getValueAsInteger(int defaultValue) {
        return defaultValue;
    }

    @Override
    public float getValueAsFloat() throws ConfigurationException {
        return 0;
    }

    @Override
    public float getValueAsFloat(float defaultValue) {
        return defaultValue;
    }

    @Override
    public String getLocation() {
        return "<no-location>";
    }
}

⏎ org/apache/fop/configuration/NullConfiguration.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)