apache/jena

View on GitHub

Apache Jena, A free and open source Java framework for building Semantic Web and Linked Data applications.

Stars: 1.4k
Forks: 713
Open beginner issues: 1
Indexed issues: 92
Avg merge: 1d 1h
Merged PRs (30d): 53

Dominant language: Java
License: Apache-2.0
Last GitHub push: Sep 19, 2026
Latest indexed: Sep 14, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted

Beginner friendly Everything

Open All

91 open issues indexed

`DISTINCT` with `ORDER BY` on a non-injective expression is rewritten to `REDUCED` and leaks duplicate rows Open

bug confirmed

Difficulty 4/5 3-5 days Newbie friendliness 55/100

apache/jena#4242 · 1 comment · Opened Sep 20, 2026
`GROUP_CONCAT(DISTINCT ...)` over an empty group returns an unbound value instead of the empty string Open

bug confirmed

Difficulty 3/5 1-2 days Newbie friendliness 68/100

apache/jena#4240 · 1 comment · Opened Sep 20, 2026
`xsd:boolean(...)` cast of `"NaN"^^xsd:double` returns `true` Open

bug confirmed

Difficulty 3/5 1-2 days Newbie friendliness 68/100

apache/jena#4239 · 1 comment · Opened Sep 20, 2026
Duration equality accepts `"PT0.5S"^^xsd:dayTimeDuration` as equal to `"P0M"^^xsd:yearMonthDuration` Open

bug

Difficulty 3/5 1-2 days Newbie friendliness 68/100

apache/jena#4237 · Opened Sep 20, 2026
Duration equality rejects `"P0Y1D"^^xsd:duration` as unequal to `"P1D"^^xsd:dayTimeDuration` Open

bug

Difficulty 3/5 1-2 days Newbie friendliness 68/100

apache/jena#4236 · Opened Sep 20, 2026
`FILTER(?v > 1e0)` accepts `"NaN"^^xsd:double` (numeric `>` comparison with `NaN` returns `true`) Open

bug confirmed

Difficulty 3/5 1-2 days Newbie friendliness 68/100

apache/jena#4235 · 1 comment · Opened Sep 20, 2026
Add GeoSPARQL 1.1 geof:centroid function Open

task

Difficulty 3/5 1-2 days Newbie friendliness 68/100

apache/jena#4233 · Opened Sep 18, 2026
Add GeoSPARQL 1.1 geof:geometryN function Open

task

Difficulty 3/5 1-2 days Newbie friendliness 65/100

apache/jena#4230 · Opened Sep 16, 2026
Add GeoSPARQL 1.1 geometry metadata functions Open

task

Difficulty 3/5 1-2 days Newbie friendliness 68/100

apache/jena#4204 · Opened Sep 7, 2026
JSON-LD: a malformed IRI is silently dropped — `checking`/`strict` and the `ErrorHandler` never sees it Open

bug JSON-LD

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

apache/jena#4175 · 6 comments · Opened Aug 28, 2026
Inconsistent Turtle writer Open

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

apache/jena#4164 · 3 comments · Opened Aug 25, 2026
TransformFilterDisjunction returns duplicate solutions for overlapping disjuncts Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 68/100

apache/jena#4160 · 1 comment · Opened Aug 21, 2026
TransactionCoordinator's exclusivitylock isn't transferred by detach()/attach() Open

Difficulty 4/5 3-5 days Newbie friendliness 55/100

apache/jena#4135 · 5 comments · Opened Aug 8, 2026
Proposal: multi-request transaction support for Fuseki, built on TDB2 Open

enhancement

apache/jena#4123 · 11 comments · 1 assignee · Opened Aug 4, 2026
Packaging of Fuseki Open

Fuseki

apache/jena#4036 · 1 assignee · Opened Jul 3, 2026
TDB2 Skip scan for single pattern queries. Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 45/100

apache/jena#3994 · 1 reaction · Opened Jun 16, 2026
SHACL 1.2 Core and SHACL 1.2 SPARQL Open

SHACL

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

apache/jena#3888 · 1 reaction · Opened May 1, 2026
Fuseki 6.0.0: canceled federated SERVICE queries can wedge the target dataset until restart Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 48/100

apache/jena#3837 · 10 comments · Opened Apr 6, 2026
Does Jena support GeoSPARQL 1.1? Open

question

Difficulty 4/5 3-5 days Newbie friendliness 45/100

apache/jena#3828 · 6 comments · Opened Apr 1, 2026
GeoSPARQL Docs update request Open

GeoSPARQL question

Difficulty 4/5 3-5 days Newbie friendliness 48/100

apache/jena#3717 · 3 comments · Opened Jan 23, 2026
Select clause disappear from where clause Open

bug Query Builder

Difficulty 3/5 1-2 days Newbie friendliness 52/100

apache/jena#3707 · 1 comment · Opened Jan 20, 2026
CDT: Literals can have the same lexical form but different values. Open

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

apache/jena#3571 · 3 comments · 1 reaction · Opened Nov 5, 2025
OntResource (in ontapi.model) is not public Open

bug

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

apache/jena#3556 · 5 comments · Opened Oct 30, 2025
Sparql Adapter System Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 28/100

apache/jena#3510 · 2 comments · Opened Oct 14, 2025
Compaction getting stuck Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 45/100

apache/jena#3488 · 12 comments · Opened Oct 2, 2025
Implement RDF Dataset Canonicalization (RDFC-1.0) with Canonical N-Quads Output Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 35/100

apache/jena#3461 · 3 comments · 2 reactions · Opened Sep 22, 2025
DSGSetup.setupTDB failing with TDB2 on partial compact Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 38/100

apache/jena#3431 · Opened Sep 9, 2025
Idle timeout expired Open

question

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

apache/jena#3345 · 5 comments · Opened Jul 24, 2025
"Attempt to assign an expression again" Error in nested WhereBuilders Open

question

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

apache/jena#3223 · 6 comments · Opened May 23, 2025
Publish a docker image up-to-date using a github actions workflow Open

enhancement

Difficulty 3/5 1-2 days Newbie friendliness 48/100

apache/jena#3165 · 3 comments · 2 reactions · Opened May 2, 2025
When using the builtin "general" AssemblerGroup, do we need to create a custom FileManger assembler? Open

OntAPI question

Difficulty 4/5 3-5 days Newbie friendliness 28/100

apache/jena#3152 · 3 comments · Opened Apr 26, 2025
Set User-Agent header for outgoing HTTP requests Open

enhancement Fuseki

Difficulty 4/5 3-5 days Newbie friendliness 48/100

apache/jena#3148 · 22 comments · Opened Apr 24, 2025
Add "version" handling when parsing Open

RDF 1.2 task

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

apache/jena#3146 · Opened Apr 24, 2025
Add support for literals with language tags to the GenericRuleReasoner's rules syntax Open

enhancement

Difficulty 3/5 1-2 days Newbie friendliness 52/100

apache/jena#3042 · 1 comment · Opened Mar 3, 2025
BIND clause slows down some queries Open

question

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

apache/jena#3021 · 19 comments · Opened Feb 19, 2025
Generating of syntactically incorrect queries when evaluating a service pattern Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 38/100

apache/jena#2995 · 1 comment · Opened Feb 7, 2025
Incorrect substitution of a variable for a blank node in a service pattern Open

bug

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

apache/jena#2994 · 7 comments · Opened Feb 7, 2025
Make `legacyDataType` accessible? Open

enhancement

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

apache/jena#2977 · 1 comment · Opened Jan 25, 2025
SHACLC: add `name, description, group, order, defaultValue` Open

enhancement SHACL

Difficulty 4/5 3-5 days Newbie friendliness 45/100

apache/jena#2853 · 4 comments · Opened Nov 19, 2024
SHACLC: support SPARQL Open

enhancement SHACL

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

apache/jena#2852 · 4 comments · Opened Nov 19, 2024
FOLD/UNFOLD aggregates highlighted as invalid in Fuseki UI Open

bug Fuseki UI

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

apache/jena#2843 · 2 comments · Opened Nov 14, 2024
Support RDF 1.2 Open

enhancement RDF 1.2

apache/jena#2805 · 2 comments · 3 reactions · 1 assignee · Opened Oct 28, 2024
Interaction of GRAPH graph patterns and subqueries Open

bug

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

apache/jena#2793 · 4 comments · Opened Oct 24, 2024
Fuseki UI: support inference options in dataset creation Open

enhancement

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

apache/jena#2764 · 5 comments · Opened Oct 10, 2024
Add support for configurable indentation length in turtle serialization Open

enhancement

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

apache/jena#2709 · 3 comments · Opened Sep 11, 2024
API call to get a snapshot of running queries Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 48/100

apache/jena#2701 · 2 comments · 2 reactions · Opened Sep 9, 2024
Logging SPARQL Updates Open

enhancement

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

apache/jena#2690 · Opened Sep 4, 2024
org.apache.jena.fuseki.servlets.ActionErrorException: Cannot read field "succ" because "n" is null Open

bug Reasoners

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

apache/jena#2616 · 2 comments · Opened Aug 1, 2024
More granular control over Blank node serialization Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 35/100

apache/jena#2549 · 1 comment · 1 reaction · Opened Jun 21, 2024
[Fuseki] Reloadable configuration files Open

enhancement Fuseki

Difficulty 5/5 Over a week Newbie friendliness 30/100

apache/jena#2462 · 5 comments · 1 reaction · Opened May 10, 2024

apache/jena

Get new issues in your inbox