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Commit 05d8345

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Olaf Hartig
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added 'LinkedDataFragment' and 'LinkedDataFragmentBase'
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‎src/org/linkeddatafragments/datasource/LinkedDataFragment.java

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package org.linkeddatafragments.datasource;
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import com.hp.hpl.jena.rdf.model.StmtIterator;
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/**
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* Represents any possible Linked Data Fragment.
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*
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* @author <a href="http://olafhartig.de">Olaf Hartig</a>
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*/
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public interface LinkedDataFragment
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{
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/**
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* Returns an iterator over the RDF data of this fragment (possibly only
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* partial if the data is paged, as indicated by {@link #isPageOnly()}).
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*/
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StmtIterator getTriples();
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/**
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* Returns true if {@link #getTriples()} returns a page of data only.
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* In this case, {@link #getPageNumber()} can be used to obtain the
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* corresponding page number.
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*/
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boolean isPageOnly();
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/**
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* Returns the number of the page of data returned by {@link #getTriples()}
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* if the data is paged (that is, if {@link #isPageOnly()} returns true).
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*
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* If the data is not paged, this method throws an exception.
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*
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* @throws UnsupportedOperationException
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* If the data of this fragment is not paged.
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*/
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long getPageNumber() throws UnsupportedOperationException;
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/**
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* Returns true if {@link #getTriples()} returns a page of data only and
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* this is the last page of the fragment.
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*
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* If the data is not paged (i.e., if {@link #isPageOnly()} returns false),
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* this method throws an exception.
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*
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* @throws UnsupportedOperationException
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* If the data of this fragment is not paged.
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*/
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boolean isLastPage() throws UnsupportedOperationException;
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/**
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* Returns the maximum number of triples per page if {@link #getTriples()}
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* returns a page of data only (that is, if {@link #isPageOnly()} returns
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* true).
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*
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* If the data is not paged, this method throws an exception.
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*
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* @throws UnsupportedOperationException
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* If the data of this fragment is not paged.
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*/
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long getMaxPageSize() throws UnsupportedOperationException;
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/**
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* Returns an iterator over the metadata of this fragment.
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*/
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StmtIterator getMetadata();
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/**
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* Returns an iterator over an RDF description of the controls associated
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* with this fragment.
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*/
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StmtIterator getControls();
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}

‎src/org/linkeddatafragments/datasource/LinkedDataFragmentBase.java

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package org.linkeddatafragments.datasource;
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import java.net.URISyntaxException;
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import org.apache.http.client.utils.URIBuilder;
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import org.linkeddatafragments.util.CommonResources;
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import com.hp.hpl.jena.rdf.model.Model;
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import com.hp.hpl.jena.rdf.model.ModelFactory;
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import com.hp.hpl.jena.rdf.model.Resource;
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import com.hp.hpl.jena.rdf.model.StmtIterator;
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/**
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* Base class of any implementation of {@link LinkedDataFragment} that uses
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* paging.
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*
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* @author <a href="http://olafhartig.de">Olaf Hartig</a>
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*/
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public abstract class LinkedDataFragmentBase implements LinkedDataFragment
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{
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public final String fragmentURL;
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public final String datasetURL;
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public final long pageNumber;
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public final boolean isLastPage;
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protected LinkedDataFragmentBase( final String fragmentURL,
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final String datasetURL,
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final long pageNumber,
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final boolean isLastPage )
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{
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this.fragmentURL = fragmentURL;
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this.datasetURL = datasetURL;
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this.pageNumber = pageNumber;
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this.isLastPage = isLastPage;
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}
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@Override
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public boolean isPageOnly() {
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return true;
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}
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@Override
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public long getPageNumber() {
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return pageNumber;
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}
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@Override
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public boolean isLastPage() {
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return isLastPage;
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}
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@Override
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public long getMaxPageSize() {
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return LinkedDataFragmentRequest.TRIPLESPERPAGE;
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}
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/**
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* This implementation uses {@link #addMetadata(Model)}, which should be
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* overridden in subclasses (instead of overriding this method).
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*/
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@Override
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public StmtIterator getMetadata()
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{
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final Model output = ModelFactory.createDefaultModel();
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addMetadata( output );
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return output.listStatements();
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}
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/**
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* This implementation uses {@link #addControls(Model)}, which should be
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* overridden in subclasses (instead of overriding this method).
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*/
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@Override
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public StmtIterator getControls()
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{
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final Model output = ModelFactory.createDefaultModel();
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addControls( output );
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return output.listStatements();
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}
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/**
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* Adds some basic metadata to the given RDF model.
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* This method may be overridden in subclasses.
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*/
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public void addMetadata( final Model model )
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{
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final Resource datasetId = model.createResource( getDatasetURI() );
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final Resource fragmentId = model.createResource( fragmentURL );
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datasetId.addProperty( CommonResources.RDF_TYPE, CommonResources.VOID_DATASET );
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datasetId.addProperty( CommonResources.RDF_TYPE, CommonResources.HYDRA_COLLECTION );
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datasetId.addProperty( CommonResources.VOID_SUBSET, fragmentId );
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fragmentId.addProperty( CommonResources.RDF_TYPE, CommonResources.HYDRA_COLLECTION );
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fragmentId.addProperty( CommonResources.RDF_TYPE, CommonResources.HYDRA_PAGEDCOLLECTION );
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}
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/**
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* Adds an RDF description of page links to the given RDF model.
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* This method may be overridden in subclasses.
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*/
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public void addControls( final Model model )
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{
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final URIBuilder pagedURL;
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try {
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pagedURL = new URIBuilder( fragmentURL );
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}
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catch ( URISyntaxException e ) {
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throw new IllegalArgumentException( e );
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}
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final Resource fragmentId = model.createResource( fragmentURL );
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final Resource firstPageId =
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model.createResource(
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pagedURL.setParameter(LinkedDataFragmentRequest.PARAMETERNAME_PAGE,
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"1").toString() );
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fragmentId.addProperty( CommonResources.HYDRA_FIRSTPAGE, firstPageId );
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if ( pageNumber > 1) {
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final String prevPageNumber = Long.toString( pageNumber - 1 );
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final Resource prevPageId =
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model.createResource(
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pagedURL.setParameter(LinkedDataFragmentRequest.PARAMETERNAME_PAGE,
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prevPageNumber).toString() );
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fragmentId.addProperty( CommonResources.HYDRA_PREVIOUSPAGE, prevPageId );
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}
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if ( ! isLastPage ) {
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final String nextPageNumber = Long.toString( pageNumber + 1 );
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final Resource nextPageId =
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model.createResource(
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pagedURL.setParameter(LinkedDataFragmentRequest.PARAMETERNAME_PAGE,
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nextPageNumber).toString() );
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fragmentId.addProperty( CommonResources.HYDRA_NEXTPAGE, nextPageId );
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}
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}
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public String getDatasetURI() {
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return datasetURL + "#dataset";
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}
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}

‎src/org/linkeddatafragments/datasource/TriplePatternFragmentBase.java renamed to ‎src/org/linkeddatafragments/datasource/TriplePatternFragmentImpl.java

File renamed without changes.

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