locationtech/proj4j

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Java port of the Proj.4 library for coordinate reprojection

Stars: 232
Forks: 86
Open beginner issues: 0
Indexed issues: 30

Dominant language: Java
License: Apache-2.0
Last GitHub push: Aug 3, 2026
Latest indexed: Sep 20, 2026
Contributing guide: Contributing guide
Code of conduct: No code of conduct
Beginner labels: help wanted
PR merge metrics: No merged PRs in 30d

Beginner friendly Everything

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30 open issues indexed

Upgrading proj4j to PROJ 9.8.1 — a plan we'd like your feedback on Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#136 · 1 comment · Opened Aug 25, 2026
Support for projjson format? Open

feature

Difficulty 4/5 3-5 days Newbie friendliness 30/100

locationtech/proj4j#122 · 3 comments · Opened Oct 10, 2025
Missing EPSG:9883 Open

feature

Difficulty 4/5 3-5 days Newbie friendliness 35/100

locationtech/proj4j#120 · 3 comments · 1 reaction · Opened May 27, 2025
Incorrect transformation when longitude >180 Open

enhancement

Difficulty 3/5 1-2 days Newbie friendliness 42/100

locationtech/proj4j#118 · 2 comments · Opened Apr 4, 2025
Will there be support for cct. Open

feature

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#114 · 2 comments · Opened Sep 27, 2024
Expose area of use Open

feature

Difficulty 4/5 3-5 days Newbie friendliness 35/100

locationtech/proj4j#113 · 1 comment · 2 reactions · Opened Sep 9, 2024
gtx files cannot be used? Open

question

Difficulty 4/5 3-5 days Newbie friendliness 25/100

locationtech/proj4j#112 · 1 comment · Opened Jun 1, 2024
Datum.isEqual maybe have a bug Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 55/100

locationtech/proj4j#110 · Opened Apr 8, 2024
rhealpix is not supported Open

feature

Difficulty 4/5 3-5 days Newbie friendliness 30/100

locationtech/proj4j#109 · 1 comment · Opened Mar 7, 2024
altitude not working when Projecting Open

feature

Difficulty 3/5 1-2 days Newbie friendliness 42/100

locationtech/proj4j#108 · 1 comment · 1 reaction · Opened Feb 20, 2024
Support for polar stereographic with alternate scales Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#106 · 4 comments · Opened Dec 8, 2023
Reprojection results seem to be too imprecise Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 30/100

locationtech/proj4j#105 · Opened Nov 2, 2023
Transforming from "EPSG:4326" to "EPSG:3857" results in precision error Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 42/100

locationtech/proj4j#104 · Opened Aug 21, 2023
VN2000 Error Exception in thread "main" java.lang.IllegalStateException: Latitude is out of range: 9738.514891355962 Open

bug

Difficulty 3/5 1-2 days Newbie friendliness 35/100

locationtech/proj4j#103 · Opened Jul 1, 2023
Improve proj4j tests to reflect the recent changes and the moved out EPSG resources Open

enhancement

Difficulty 3/5 1-2 days Newbie friendliness 35/100

locationtech/proj4j#96 · 3 comments · 2 reactions · Opened Dec 13, 2022
ntv2 grid support Open

enhancement

locationtech/proj4j#89 · 19 comments · 1 assignee · Opened Nov 17, 2022
Use of PROJ string or WKT string is prone to definition ambiguities Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#69 · Opened Nov 5, 2020
1 degree == 1 metre according to units Open

Difficulty 4/5 3-5 days Newbie friendliness 20/100

locationtech/proj4j#68 · Opened Oct 20, 2020
More flexible readEpsgFromParameters function Open

bug enhancement

Difficulty 3/5 1-2 days Newbie friendliness 38/100

locationtech/proj4j#65 · Opened Aug 15, 2020
NullPointerException on transform() when using CoordinateReferenceSystem.CS_GEO Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

locationtech/proj4j#56 · Opened Jan 30, 2020
Use of proj's sqlite database Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#53 · 2 comments · 1 reaction · Opened Sep 23, 2019
Provide best-in-class WKT -> Proj4 conversion routines Open

enhancement help wanted

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#49 · 9 comments · Opened Aug 25, 2019
Projection.initialize() method Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#40 · 6 comments · Opened Aug 15, 2019
LandsatProjection: Inverse? Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#39 · 1 comment · Opened Aug 15, 2019
ProjCoordinate: Z ordinate Open

Difficulty 2/5 1-3 hours Newbie friendliness 55/100

locationtech/proj4j#37 · 1 comment · Opened Aug 12, 2019
Projection.getEPSGCode() always returns 0 Open

help wanted

Difficulty 4/5 3-5 days Newbie friendliness 35/100

locationtech/proj4j#24 · 2 comments · Opened Mar 18, 2019
Support for constructing CRS from an OGC URN Open

enhancement

Difficulty 3/5 1-2 days Newbie friendliness 45/100

locationtech/proj4j#23 · 1 comment · Opened Mar 16, 2019
No support for vertical keywords such as geoidgrids and vunits Open

enhancement feature

Difficulty 3/5 1-2 days Newbie friendliness 45/100

locationtech/proj4j#20 · 2 reactions · Opened Jan 7, 2019
How to incorporate proj 5.0 changes? Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

locationtech/proj4j#12 · 9 comments · Opened May 21, 2018
Develop approach to run PROJ.4 unit tests Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

locationtech/proj4j#9 · 2 comments · Opened Mar 16, 2018

locationtech/proj4j

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