I have improved my program which I am posting here in case it could be useful to others.
Code: Select allpackage com.openkm.workflow.archivage;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.Statement;
import org.jbpm.graph.def.ActionHandler;
import org.jbpm.graph.exe.ExecutionContext;
import com.openkm.bean.form.*;
public class InsertionMysql implements ActionHandler {
  /**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	//int date = 10;
	//String direction = "informatique";
	//String ordonnateur = "KOUADIO";
	//String document = "stage";
	//String justificatif = "Rappoart de stage";
	//String description = "Stage pratique";
	//String duree = "2 mois";
	//String observations = "RAS";
	
	 
@Override
public void execute(ExecutionContext executionContext) throws Exception {
	
	Input date = (Input)executionContext.getContextInstance().getVariable("date");
	Select direction = (Select) executionContext.getContextInstance().getVariable("direction");
	Select requerant = (Select)executionContext.getContextInstance().getVariable("requerant");
	Input document = (Input)executionContext.getContextInstance().getVariable("document");
	Input justificatif = (Input)executionContext.getContextInstance().getVariable("justificatif");
	TextArea description = (TextArea)executionContext.getContextInstance().getVariable("description");
	Input duree = (Input)executionContext.getContextInstance().getVariable("duree");
	TextArea observations = (TextArea)executionContext.getContextInstance().getVariable("observations");
	Input avisarchiviste = (Input)executionContext.getContextInstance().getVariable("avisarchiviste");
	Input dateretour = (Input)executionContext.getContextInstance().getVariable("dateretour");
	// Input relance = (Input)executionContext.getContextInstance().getVariable("relance");
	Input noteimportante = (Input)executionContext.getContextInstance().getVariable("noteimportante");
	Input dateeffectiveretour = (Input)executionContext.getContextInstance().getVariable("dateeffectiveretour");
	Input retard = (Input)executionContext.getContextInstance().getVariable("retard");
	Input commentaire = (Input)executionContext.getContextInstance().getVariable("commentaire");
	String myDriver = "com.mysql.jdbc.Driver";
      String myUrl = "jdbc:mysql://localhost:3306/okmdb";
      Class.forName(myDriver);
      Connection conn = DriverManager.getConnection(myUrl, "kouadio", "1234");
      
      Statement st = conn.createStatement();
  //    String sql1 = "INSERT INTO WORKFLOW_ARCHIVAGE (Ordre, Date, Direction, Requerant, document, Justificatif, Description, Duree, Observations) VALUES (Null, CURRENT_DATE(), '" + direction.getValue() + "', '" + requerant.getValue()+ "', '" + document.getValue()+ "', '" + justificatif.getValue()+ "', '" + description.getValue()+ "', '" + duree.getValue() +"', '" + observations.getValue()+"')";
      String sql2 = "INSERT INTO WORKFLOW_ARCHIVAGE (Ordre, Date, Direction, Requerant, document, Justificatif, Description, Duree, Observations, avisarchiviste, dateretour, noteimportante, dateeffectiveretour, retard, commentaire) VALUES (Null, CURRENT_DATE(), '" + direction.getValue() + "', '" + requerant.getValue()+ "', '" + document.getValue()+ "', '" + justificatif.getValue()+ "', '" + description.getValue()+ "', '" + duree.getValue() +"', '" + observations.getValue()+"', '"+ avisarchiviste.getValue()+"', '"+ dateretour.getValue()+"', '"+ noteimportante.getValue()+"', '"+ dateeffectiveretour.getValue()+"', '"+ retard.getValue()+"', '"+ commentaire.getValue()+"')";
      
  //    if (executionContext.getContextInstance().getVariable("dateeffectiveretour") == null) {
    	  
   // 	  st.executeUpdate(sql1);
   //   }
   //   else {
    	  st.executeUpdate(sql2);  
   //   }
      
 
      conn.close();
  
  }
}