Redland - RDF Application Framework - Java Interface

Redland Java interface

This is built if --with-java is given to the configure line, or --with-java=java to use a particular Java version/program.

The --with-jdk configure argument MUST be given give the location of the root of the full JDK installation so that the interface can be properly compiled against the correct Java Native Interface (JNI) headers for the JDK that provides the java program.

The standard 'make' at the top level will build it once enabled as above. You can also compile the Java interface by hand as follows:

  cd java
  make
  make check  # optional

(the make check may fail without the files being installed)

To install it system wide (this is optional) do this as root:

  root# make install

which will copy the librdf-java.jar to PREFIX/share/java and the shared library librdf-java.so to PREFIX/lib. This is not a standard location between systems so might have to be done by hand.



The Redland Java interface has been tested with JD2SDK 1.4.2,
 J2SDK 1.4.1_01 and J2SDK 1.3.1 on Linux/x86 only.  The JNI header
 and library files are in different places on all systems so the
 --with-jdk MUST be used to give the location of the root
 of the full JDK installation.  This should then find the header
 files in the include and include/system
 sub-directories (such as "solaris" or "linux").


Testing the Redland Java interface

There is the beginnings of an example program in
example.java
which is mostly for reading (along with the test1.java)
but can be compiled and run with:
  make example

which tries to set the shared library path for librdf-java.so


Redland Java API Introduction

The Java API is an object-based API reflecting the same structure
of the Redland objects with simple mappings between them:




Concept Redland Class Java Class Purpose


Resource / Literal librdf_node org.librdf.redland.Node
RDF Model & Syntax nodes


Statement / Triple librdf_statement org.librdf.redland.Statement
RDF Model & Syntax arcs (statements, triples) [isa Resource]


Model librdf_model org.librdf.redland.Model
Set of Statements usually held in one Storage.


Storage librdf_storage org.librdf.redland.Storage
Storage for Models either persistant or in-memory.


Stream librdf_stream org.librdf.redland.Stream
Providing sequences of Statements from Parsers, queries.


Parser librdf_parser org.librdf.redland.Parser
Syntax parsers delivering Stream of Statements or writing to a Model


Serializer librdf_serializer org.librdf.redland.Serializer
Serialize Models into various syntaxes such as RDF/XML.


Iterator librdf_iterator org.librdf.redland.Iterator
Enumerating lists (of Node) from queries.


URI librdf_uri org.librdf.redland.URI
Provides URIs for Resources, Parsers, ...


World   org.librdf.redland.World
RDF wrapper class handling Redland startup/shutdown


Digest librdf_digest  
Internal content digest class


Hash librdf_hash  
Internal key:value maps class


List librdf_list  
Internal list class





Other RDF Java APIs and applications

The follow are useful pure-Java applications (no C library)

Jena Semantic Web Toolkit by the HP Labs Semantic Web group, Bristol, UK.  Originally started by Brian McBride.


ARP: Another RDF Parser, by Jeremy Carroll, HP Labs.  Now part of Jena.

Sesame which provides an architecture for persistent storage and querying of RDF and RDF Schema, using an RDF Schema Query Language (RQL).  Developed by aidministrator and OntoText. 

KAON open-source ontology management infrastructure based on the J2EE Java Beans framework.  Developed by FZI / AIFB, University of Karlsruhe






Copyright 2001-2003 Dave Beckett, Institute for Learning and Research Technology, University of Bristol

Concept	Redland Class	Java Class	Purpose
Resource / Literal	librdf_node	`org.librdf.redland.Node`	RDF Model & Syntax nodes
Statement / Triple	librdf_statement	`org.librdf.redland.Statement`	RDF Model & Syntax arcs (statements, triples) [isa Resource]
Model	librdf_model	`org.librdf.redland.Model`	Set of Statements usually held in one Storage.
Storage	librdf_storage	`org.librdf.redland.Storage`	Storage for Models either persistant or in-memory.
Stream	librdf_stream	`org.librdf.redland.Stream`	Providing sequences of Statements from Parsers, queries.
Parser	librdf_parser	`org.librdf.redland.Parser`	Syntax parsers delivering Stream of Statements or writing to a Model
Serializer	librdf_serializer	`org.librdf.redland.Serializer`	Serialize Models into various syntaxes such as RDF/XML.
Iterator	librdf_iterator	`org.librdf.redland.Iterator`	Enumerating lists (of Node) from queries.
URI	librdf_uri	`org.librdf.redland.URI`	Provides URIs for Resources, Parsers, ...
World		`org.librdf.redland.World`	RDF wrapper class handling Redland startup/shutdown
Digest	librdf_digest		Internal content digest class
Hash	librdf_hash		Internal key:value maps class
List	librdf_list		Internal list class