package kg.apc.jmeter.functions;

 import java.util.Arrays;

 import java.util.Collection;

 import java.util.LinkedList;

 import java.util.List;

 import org.apache.jmeter.engine.util.CompoundVariable;

 import org.apache.jmeter.functions.AbstractFunction;

 import org.apache.jmeter.functions.InvalidVariableException;

 import org.apache.jmeter.samplers.SampleResult;

 import org.apache.jmeter.samplers.Sampler;

 import org.apache.jmeter.threads.JMeterVariables;

 import org.apache.jorphan.logging.LoggingManager;

 import org.apache.log.Logger;

 public class Substring extends AbstractFunction {

     private static final List<String> desc = new LinkedList<String>();

     private static final String KEY = "__substring";

     static {

         desc.add("String to get part of");

         desc.add("Begin index (first is 0)");

         desc.add("End index");

         desc.add("Name of variable in which to store the result (optional)");

     }

     private Object[] values;

     public Substring() {

     }

     @Override

     public synchronized String execute(SampleResult previousResult, Sampler currentSampler)

             throws InvalidVariableException {

         String str = getParameter(0);

         int begin = Integer.parseInt(getParameter(1).trim());

         int len = Integer.parseInt(getParameter(2).trim());

         String totalString = str.substring(begin, len);

         JMeterVariables vars = getVariables();

         if (values.length > 3) {

             String varName = getParameter(3);

             if (vars != null && varName != null && varName.length() > 0) {// vars will be null on TestPlan

                 vars.put(varName, totalString);

             }

         }

         return totalString;

     }

     @Override

     public synchronized void setParameters(Collection<CompoundVariable> parameters) throws InvalidVariableException {

         checkMinParameterCount(parameters, 3);

         values = parameters.toArray();

     }

     @Override

     public String getReferenceKey() {

         return KEY;

     }

     @Override

     public List<String> getArgumentDesc() {

         return desc;

     }

     private String getParameter(int i) {

         return ((CompoundVariable) values[i]).execute();

     }

 }