HistoricalGraphFormaterElement.java

package com.hp.hpl.jena.sparql.serializer;

import java.util.HashMap;
import java.util.Map;

import org.apache.jena.atlas.io.IndentedLineBuffer;
import org.apache.jena.atlas.io.IndentedWriter;

import com.hp.hpl.jena.sparql.core.PathBlock;
import com.hp.hpl.jena.sparql.core.TriplePath;
import com.hp.hpl.jena.sparql.syntax.ElementNamedGraph;
import com.hp.hpl.jena.sparql.syntax.ElementPathBlock;

import eu.play_project.play_platformservices_querydispatcher.historicalQuery.DetectCloudId;

public class HistoricalGraphFormaterElement extends FormatterElement {
	
	Map<String, String> historicalCloudQueries = new HashMap<String, String>();

	public HistoricalGraphFormaterElement(IndentedWriter out, SerializationContext context) {
		super(out, context);
	}
	
	
	  @Override
	    public void visit(ElementNamedGraph el)
	    {

	    	//PLAY: Replace output buffer temporally to get one graph only
	    	IndentedWriter original = super.out;
	    	
	    	super.out = new IndentedLineBuffer();
	    	
	    	//Set start state.
	    	DetectCloudId.startGraph();
	    	//Process elements.
	        visitNodePattern("GRAPH", el.getGraphNameNode(), el.getElement()) ;
	        //Set end state.
	        DetectCloudId.endGraph();
	        
	        //Save cloud ID and the corresponding query.
	        if(historicalCloudQueries.containsKey(DetectCloudId.getCloudId())){
	        	historicalCloudQueries.put(DetectCloudId.getCloudId(), historicalCloudQueries.get(DetectCloudId.getCloudId()) + "\n" + out.toString());
	        }else{
		        historicalCloudQueries.put(DetectCloudId.getCloudId(), out.toString());
	        }
	        
	        //Continue with old buffer.
	        super.out = original;
   
	    }
	    
	@Override
	public void visit(ElementPathBlock el) {
		
		// Use from serialization from parent class.
		super.visit(el);

		// Search cloud id.
		PathBlock pBlk = el.getPattern();
		for (TriplePath tp : pBlk) {
			DetectCloudId.newTriple(tp.getPredicate().toString(), tp.getObject().toString());
		}

	}

	public Map<String, String> getHistoricalCloudQueries() {
		return historicalCloudQueries;
	}

	//Generate string representation of prefixes.
	public String getPrefixNames() {
		String prefixes ="";
		// Get prefix names ans serialize them.
		for (String key : super.context.getPrefixMapping()
				.getNsPrefixMap().keySet()) {
			prefixes += "PREFIX "
					+ key
					+ ": <"
					+ super.context.getPrefixMapping().getNsPrefixMap()
							.get(key) + "> \n";
		}
		return prefixes;
	}
}