net.fortytwo.sesametools.ContextInsensitiveStatementComparator Maven / Gradle / Ivy

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package net.fortytwo.sesametools;

import java.util.Comparator;

import org.openrdf.model.Statement;

/**
 * Implements a Comparator for OpenRDF Statements 
 * using the order Subject->Predicate->Object
 * 
 * @author Peter Ansell [email protected]
 */
public class ContextInsensitiveStatementComparator implements Comparator
{
	public final static int BEFORE = -1;
	public final static int EQUALS = 0;
	public final static int AFTER = 1;

	@Override
	public int compare(Statement first, Statement second)
	{
		if(first == second)
		{
			return EQUALS;
		}
		
		if(first.getSubject().equals(second.getSubject()))
		{
			if(first.getPredicate().equals(second.getPredicate()))
			{
				if(first.getObject().equals(second.getObject()))
				{
				    return EQUALS;
				}
				else
				{
					return new ValueComparator().compare(first.getObject(), second.getObject());
				}
			}
			else
			{
				return new ValueComparator().compare(first.getPredicate(), second.getPredicate());
			}
		}
		else
		{
			return new ValueComparator().compare(first.getSubject(), second.getSubject());
		}
	}

}