Apache Jena3 is a major version release for Jena - it is not binary compatible with Jena2. The migration consists of package renaming and database reloading.
- Package renaming
- RDF 1.1 Semantics for plain literals
- Persistent data (TDB, SDB) should be reloaded.
- Java8 is required.
- Security renamed to Permissions. Security Evaluator changes required
Package Name Changes
Packages with a base name of
Global replacement of
import com.hp.hpl.jena. with
import org.apache.jena. will cover the majority of cases.
The Jena APIs remain unchanged expect for this renaming.
Only java package names are being changed. Vocabularies are not affected.
Migration support is provided by mapping
ja:loadClass names beginning
com.hp.hpl.jena internally to
org.apache.jena. A warning is logged.
This will also affect logging: logger names reflect the java class naming
so loggers for
Many of the changes and refinements for RDF 1.1 are already in Jena2. The parsers for Turtle-family languages already follow the RDF 1.1 grammars and output is compatible with RDF 1.1 as well as earlier output details.
RDF 1.1 changes for plain literals
In RDF 1.1, all literals have a datatype. The datatype of a plain
literal with no language tag (also called a “simple literal”) has datatype
xsd:string. A plain literal with a language tag has datatype
"abc"^^xsd:string are the same RDF term in RDF 1.1. Jena2
memory models have always treated these as the same value, but different
terms. Jena2 persistent models treated them as two separate term and two
Data is not invalidated by this change.
The parsers will give datatypes to all data read, there is no need to change the data.
Output is in the datatype-less form (an abbreviated syntax) even in N-triples.
Applications which explicitly use
^^xsd:string(or in RDF/XML,
rdf:datatype="http://www.w3.org/2001/XMLSchema#string") will see a change in appearance.
Applications with a mix of plain literals and explicit
^^xsd:string(the RDF 1.1 Work Group believed these to be uncommon) may see changes.
Applications that do their own RDF output need to be careful to not assume that having datatype excludes the possibility of also having a language tag.
Data that does not use explicit
xsd:string should be safe but it is still
recommended that data is reloaded at a convenient time.
Data that does use explicit
xsd:string must be reloaded.
Security package renamed to Permissions
Jena Security has been renamed Jena Permissions and the Maven artifact id has been changed to jena-permissions to reflect this change.
Shim code that was introduced to map Jena classes to security classes
has been removed. This change requires changes to
implementations. More details are available at the
GraphStoreinterface has been removed
ModelFactory.createFileModelMakerhas been removed
LateBindingIteratorhas been removed: use
EarlyBindingIteratorhas been removed: no replacement
UniqueExtendedIteratorhas been removed: use
ExtendedIteratorwith unique filter