org.apache.jena.hadoop.rdf.io.registry

Class HadoopRdfIORegistry

java.lang.Object

org.apache.jena.hadoop.rdf.io.registry.HadoopRdfIORegistry

public class HadoopRdfIORegistry
extends Object

A registry which is used by various classes to dynamically select record readers and writers based on a provided Lang

Readers and writers are dynamically discovered using the Java ServiceLoader mechanism. This will look for files under META-INF/services named org.apache.jena.hadoop.rdf.io.registry.ReaderFactory and org.apache.jena.hadoop.rdf.io.registry.WriterFactory. This follows the standard ServiceLoader format of provided one class name per line which implements the relevant interface.

Constructor Summary

Constructors

Constructor and Description
HadoopRdfIORegistry()

Method Summary

Modifier and Type	Method and Description
static void	addReaderFactory(ReaderFactory f) Registers the reader factory for all the languages it declares itself as supporting
static void	addWriterFactory(WriterFactory f) Registers the writer factory for all the languages it declares itself as supporting
static org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,QuadWritable>	createQuadReader(Lang lang) Tries to create a quad reader for the given language
static <TKey> org.apache.hadoop.mapreduce.RecordWriter<TKey,QuadWritable>	createQuadWriter(Lang lang, Writer writer, org.apache.hadoop.conf.Configuration config) Tries to create a quad writer for the given language
static org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,TripleWritable>	createTripleReader(Lang lang) Tries to create a triple reader for the given language
static <TKey> org.apache.hadoop.mapreduce.RecordWriter<TKey,TripleWritable>	createTripleWriter(Lang lang, Writer writer, org.apache.hadoop.conf.Configuration config) Tries to create a triple writer for the given language
static boolean	hasQuadReader(Lang lang) Gets whether there is a quad reader available for the given language
static boolean	hasQuadWriter(Lang lang) Gets whether there is a quad writer available for the given language
static boolean	hasTriplesReader(Lang lang) Gets whether there is a triple reader available for the given language
static boolean	hasTriplesWriter(Lang lang) Gets whether there is a triple writer available for the given language
static void	reset() Resets the registry to the default configuration

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HadoopRdfIORegistry

public HadoopRdfIORegistry()

Method Detail

reset

public static void reset()

Resets the registry to the default configuration

addReaderFactory

public static void addReaderFactory(ReaderFactory f)

Registers the reader factory for all the languages it declares itself as supporting

Parameters:

f - Reader factory

addWriterFactory

public static void addWriterFactory(WriterFactory f)

Registers the writer factory for all the languages it declares itself as supporting

Parameters:

f - Writer factory

hasQuadReader

public static boolean hasQuadReader(Lang lang)

Gets whether there is a quad reader available for the given language

Parameters:

lang - Language

Returns:

True if available, false otherwise

hasTriplesReader

public static boolean hasTriplesReader(Lang lang)

Gets whether there is a triple reader available for the given language

Parameters:

lang - Language

Returns:

True if available, false otherwise

createQuadReader

public static org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,QuadWritable> createQuadReader(Lang lang)
                                                                                                                 throws IOException

Tries to create a quad reader for the given language

Parameters:

lang - Language

Returns:

Quad reader if one is available

Throws:

IOException - Thrown if a quad reader is not available or the given language does not support quads

createTripleReader

public static org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,TripleWritable> createTripleReader(Lang lang)
                                                                                                                     throws IOException

Tries to create a triple reader for the given language

Parameters:

lang - Language

Returns:

Triple reader if one is available

Throws:

IOException - Thrown if a triple reader is not available or the given language does not support triple

hasQuadWriter

public static boolean hasQuadWriter(Lang lang)

Gets whether there is a quad writer available for the given language

Parameters:

lang - Language

Returns:

True if available, false otherwise

hasTriplesWriter

public static boolean hasTriplesWriter(Lang lang)

Gets whether there is a triple writer available for the given language

Parameters:

lang - Language

Returns:

True if available, false otherwise

createQuadWriter

public static <TKey> org.apache.hadoop.mapreduce.RecordWriter<TKey,QuadWritable> createQuadWriter(Lang lang,
                                                                                                  Writer writer,
                                                                                                  org.apache.hadoop.conf.Configuration config)
                                                                                           throws IOException

Tries to create a quad writer for the given language

Parameters:

lang - Language

writer - Writer

config - Configuration

Returns:

Quad writer if one is available

Throws:

IOException - Thrown if a quad writer is not available or the given language does not support quads

createTripleWriter

public static <TKey> org.apache.hadoop.mapreduce.RecordWriter<TKey,TripleWritable> createTripleWriter(Lang lang,
                                                                                                      Writer writer,
                                                                                                      org.apache.hadoop.conf.Configuration config)
                                                                                               throws IOException

Tries to create a triple writer for the given language

Parameters:

lang - Language

writer - Writer

config - Configuration

Returns:

Triple writer if one is available

Throws:

IOException - Thrown if a triple writer is not available or the given language does not support triple