// BSD License (http://www.galagosearch.org/license)

 package org.galagosearch.tupleflow;

 import org.galagosearch.tupleflow.execution.ErrorHandler;

 import org.galagosearch.tupleflow.execution.Verification;

 import java.io.IOException;

 /**

  *

  * @author trevor

  */

 public class NullSource<T> implements ExNihiloSource<T> {

     public Processor<T> processor;

     Class<T> outputClass;

     public NullSource(TupleFlowParameters parameters) throws ClassNotFoundException {

         String className = parameters.getXML().get("class");

         this.outputClass = (Class<T>) Class.forName(className);

     }

     public NullSource(Class<T> outputClass) {

         this.outputClass = outputClass;

     }

     public static void verify(TupleFlowParameters parameters, ErrorHandler handler) {

         Verification.requireParameters(new String[]{"class"}, parameters.getXML(), handler);

         Verification.requireClass(parameters.getXML().get("class"), handler);

     }

     public void setProcessor(Step processor) throws IncompatibleProcessorException {

         Linkage.link(this, processor);

     }

     public void run() throws IOException {

         processor.close();

     }

     public static String getOutputClass(TupleFlowParameters parameters) {

         return parameters.getXML().get("class", "");

     }

 }