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/fo/properties/LengthProperty.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: LengthProperty.java 1303891 2012-03-22 17:04:12Z vhennebert $ */

package org.apache.fop.fo.properties;

import org.apache.xmlgraphics.util.UnitConv;

import org.apache.fop.datatypes.Length;
import org.apache.fop.datatypes.Numeric;
import org.apache.fop.fo.FObj;
import org.apache.fop.fo.PropertyList;
import org.apache.fop.fo.expr.PropertyException;

/**
 * Superclass for properties wrapping a Length value.
 */
public abstract class LengthProperty extends Property
    implements Length, Numeric {

    /**
     * Inner class for making instances of LengthProperty
     */
    public static class Maker extends PropertyMaker {

        /**
         * Constructor
         *
         * @param propId the id of the property for which a Maker should be created
         */
        public Maker(int propId) {
            super(propId);
        }

        /** {@inheritDoc} */
        @Override
        public Property convertProperty(Property p,
                                        PropertyList propertyList,
                                        FObj fo) throws PropertyException {
            if (p instanceof EnumProperty) {
                return new EnumLength(p);
            }
            if (p instanceof LengthProperty) {
                return p;
            }
            if (p instanceof NumberProperty) {
                //Assume pixels (like in HTML) when there's no unit
                float resolution = propertyList.getFObj().getUserAgent().getSourceResolution();
                return FixedLength.getInstance(
                        p.getNumeric().getNumericValue(), "px",
                        UnitConv.IN2PT / resolution);
            }
            Length val = p.getLength();
            if (val != null) {
                return (Property) val;
            }
            /* always null ?? */
            return convertPropertyDatatype(p, propertyList, fo);
        }

    }

    /** @return the numeric dimension. Length always a dimension of 1 */
    public int getDimension() {
        return 1;
    }

    /** @return this.length cast as a Numeric */
    @Override
    public Numeric getNumeric() {
        return this;
    }

    /** @return this.length */
    @Override
    public Length getLength() {
        return this;
    }

    /** @return this.length cast as an Object */
    @Override
    public Object getObject() {
        return this;
    }

}

⏎ org/apache/fop/fo/properties/LengthProperty.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)