JPX is a Java library for creating, reading and writing GPS data in GPX format. It is a full implementation of version 1.1 of the GPX format. The data classes are completely immutable and allows a functional programming style. They are working also nicely with the Java 8 Stream API.

The comprehensive Javadoc of the library can be here.

• JRE 8: Java runtime version 8 is needed for using the library.

• JDK 8: The Java JDK 8 must be installed.
• Gradle 3.x: Gradle is used for building the library. (Gradle is download automatically, if you are using the Gradle Wrapper script ./gradlew, located in the base directory, for building the library.)
• TestNG 6.10: JPX uses TestNG framework for unit tests.

For building the JPX library you have to check out the master branch from Github.

$ git clone https://github.com/jenetics/jpx.git

Executing the tests:

$ cd jpx
$ ./gradle test

Building the library:

$ ./gradle jar

• Github: https://github.com/jenetics/jpx/archive/v1.0.1.zip
• Maven: io.jenetics:jpx:1.0.1 on Maven Central

final GPX gpx = GPX.builder()
    .addTrack(track -> track
        .addSegment(segment -> segment
            .addPoint(p -> p.lat(48.2081743).lon(16.3738189).ele(160))
            .addPoint(p -> p.lat(48.2081743).lon(16.3738189).ele(161))
            .addPoint(p -> p.lat(48.2081743).lon(16.3738189).ele(162))))
    .build();

Writing GPX object to a file

GPX.write(gpx, "gpx.xml");

GPX output

<?xml version="1.0" encoding="UTF-8"?>
<gpx version="1.1" creator="JPX - Java GPX library" xmlns="http://www.topografix.com/GPX/1/1">
    <trk>
        <trkseg>
            <trkpt lat="48.2081743" lon="16.3738189">
                <ele>160.0</ele>
            </trkpt>
            <trkpt lat="48.2081743" lon="16.3738189">
                <ele>161.0</ele>
            </trkpt>
            <trkpt lat="48.2081743" lon="16.3738189">
                <ele>162.0</ele>
            </trkpt>
        </trkseg>
    </trk>
</gpx>

This example writes a given GPX object to a file, reads it again and prints the WayPoints of all tracks and all track-segments to the console.

GPX.write(gpx, "gpx.xml");
GPX.read("gpx.xml").tracks()
    .flatMap(Track::segments)
    .flatMap(TrackSegment::points)
    .forEach(System.out::println);

Console output

$ [lat=48.2081743, lon=48.2081743, ele=160]
$ [lat=48.2081743, lon=48.2081743, ele=161]
$ [lat=48.2081743, lon=48.2081743, ele=162]

final Point start = WayPoint.of(47.2692124, 11.4041024);
final Point end = WayPoint.of(47.3502, 11.70584);
final Length distance = Geoid.WGS84.distance(start, end);
System.out.println(distance);

Console output

$ 24528.356073554987 m

Calculate the path length of the first track-segment.

final Length length = gpx.tracks()
    .flatMap(Track::segments)
    .findFirst()
    .map(TrackSegment::points).orElse(Stream.empty())
    .collect(Geoid.WGS84.toPathLength());

The library is licensed under the Apache License, Version 2.0.

Copyright 2016-2017 Franz Wilhelmstötter

Licensed 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.

• #5: Fix exception handling for empty XML elements: e.g. <ele/>.
• #15: Fix NPE when creating Copyright object with null license string.

• #6: Improve error handling for invalid GPX files.