https://github.com/locationtech/proj4j

Java port of the Proj.4 library for coordinate reprojection
https://github.com/locationtech/proj4j

geodesy gis java proj4j projection

Last synced: 2 days ago
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Java port of the Proj.4 library for coordinate reprojection

• Host: GitHub
• URL: https://github.com/locationtech/proj4j
• Owner: locationtech
• License: other
• Created: 2017-10-16T18:27:26.000Z (about 7 years ago)
• Default Branch: master
• Last Pushed: 2023-12-24T16:46:11.000Z (11 months ago)
• Last Synced: 2024-11-08T08:45:58.689Z (9 days ago)
• Topics: geodesy, gis, java, proj4j, projection
• Language: Java
• Homepage:
• Size: 2.03 MB
• Stars: 186
• Watchers: 16
• Forks: 73
• Open Issues: 27
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

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README

        
# Proj4J [![GitHub Action Status](https://github.com/locationtech/proj4j/workflows/CI/badge.svg)](https://github.com/locationtech/proj4j/actions) [![Maven Central](https://img.shields.io/maven-central/v/org.locationtech.proj4j/proj4j)](https://search.maven.org/search?q=g:org.locationtech.proj4j%20AND%20a:proj4j)

Proj4J is a Java library for converting coordinates between different geospatial coordinate reference systems.

It is designed to be compatible with `proj.4` parameters and derives some of its implementation from the `proj.4` sources.

Proj4J is a project in the [LocationTech](http://www.locationtech.org) working group of the Eclipse Foundation.

![LocationTech](locationtech_mark.png) 

## User Guide

Proj4J artifacts are available on maven central.

**!Important!** As of `1.2.2` version, `proj4-core` contains no EPSG Licensed files. 

In order to make proj4j properly operate, it makes sense to consider `proj4-epsg` dependency usage.

### Using Proj4J with Maven

To include Proj4J in a Maven project, add a dependency block like the following:

```xml

    {latest version}

    org.locationtech.proj4j

    proj4j

    ${proj4j.version}

```

where `{latest version}` refers to the version indicated by the badge above.

#### Proj4j EPSG

`Proj4J-EPSG` module distributes a portion of the EPSG dataset. This artifact is released the [EPSG database distribution license](https://raw.githubusercontent.com/locationtech/proj4j/master/LICENSE.EPSG).

To include `Proj4J-EPSG` in a Maven project, add a dependency block like the following:

```xml

    {latest version}

    org.locationtech.proj4j

    proj4j-epsg

    ${proj4j.version}

```

where `{latest version}` refers to the version indicated by the badge above.

### Using Proj4J with Gradle

To include Proj4J in a Gradle project, add a dependency block like the following:

```

dependencies {

    implementation 'org.locationtech.proj4j:proj4j:{latest version}'

}

```

where `{latest version}` refers to the version indicated by the badge above.

#### Proj4j EPSG

`Proj4J-EPSG` module distributes a portion of the EPSG dataset. This artifact is released the [EPSG database distribution license](https://raw.githubusercontent.com/locationtech/proj4j/master/LICENSE.EPSG).

To include `Proj4J-EPSG` in a Gradle project, add the following line to the dependency block:

```

    implementation 'org.locationtech.proj4j:proj4j-epsg:{latest version}'

```

where `{latest version}` refers to the version indicated by the badge above.

### Basic Usage

The following examples give a quick intro on how to use Proj4J in common

use cases.

#### Transforming coordinates from WGS84 to UTM

##### Obtaining CRSs by name

```Java

CRSFactory crsFactory = new CRSFactory();

CoordinateReferenceSystem WGS84 = crsFactory.createFromName("epsg:4326");

CoordinateReferenceSystem UTM = crsFactory.createFromName("epsg:25833");

```

##### Obtaining CRSs using parameters

```Java

CRSFactory crsFactory = new CRSFactory();

CoordinateReferenceSystem WGS84 = crsFactory.createFromParameters("WGS84",

    "+proj=longlat +datum=WGS84 +no_defs");

CoordinateReferenceSystem UTM = crsFactory.createFromParameters("UTM",

    "+proj=utm +zone=33 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs");

```

##### Transforming coordinates

```Java

CoordinateTransformFactory ctFactory = new CoordinateTransformFactory();

CoordinateTransform wgsToUtm = ctFactory.createTransform(WGS84, UTM);

// `result` is an output parameter to `transform()`

ProjCoordinate result = new ProjCoordinate();

wgsToUtm.transform(new ProjCoordinate(lon, lat), result);

```

## Building, Testing and installing locally

`mvn clean install`

## Publish to Maven Central

`mvn -Dmaven.test.skip=true -Pcentral clean package deploy`

For more details see [HOWTORELEASE.txt](./HOWTORELEASE.txt).

## Contributing

If you are interested in contributing to Proj4J please read the [**Contributing Guide**](CONTRIBUTING.md).