stroing documents in subfolders by using filenet content engine API

import com.filenet.api.collection.ContentElementList;
import com.filenet.api.collection.FolderSet;
import com.filenet.api.constants.AutoClassify;
import com.filenet.api.constants.AutoUniqueName;
import com.filenet.api.constants.CheckinType;
import com.filenet.api.constants.DefineSecurityParentage;
import com.filenet.api.constants.RefreshMode;
import com.filenet.api.core.*;
import java.io.File;
import java.io.FileInputStream;
import java.util.Iterator;

public class StoringDataInSubFolders {

    public static void main(String args[])
    {
     
        EngineConnection mine=new EngineConnection();
       
        Connection connection = mine.giveConnection();
       
        if(connection!=null)
        {
           
            Domain domain=Factory.Domain.fetchInstance(connection, null, null);
           
            System.out.println(""+domain.get_Name());
           
            //select an object store
           
            ObjectStore object_store=Factory.ObjectStore.fetchInstance(domain, "CMTOS", null);
           
            System.out.println(""+object_store.get_DisplayName());
           
            //select a folder
           
            Folder current_folder=null;
          
          
            Folder selected_folder=null;
           
            FolderSet folder_set=object_store.get_TopFolders();
           
            Iterator<FolderSet> folder_iterator=folder_set.iterator();
           
            while(folder_iterator.hasNext())
            {
               
                current_folder=(Folder)folder_iterator.next();
               
                if(current_folder.get_FolderName().equals("Practise Folder"))
                {
                    selected_folder=current_folder;
                }
            }
           
            System.out.println(""+selected_folder.get_FolderName());
           
            //get sub folders from selected folders
           
           FolderSet sub_folder_set= selected_folder.get_SubFolders();
          
           //iterate through sub folders
          
           Iterator<FolderSet> sub_folder_iterator=sub_folder_set.iterator();
          
           Folder current_sub_folder=null;
          
           Folder selected_sub_folder=null;
          
           while(sub_folder_iterator.hasNext())
           {
              
               current_sub_folder=(Folder)sub_folder_iterator.next();
              
               if(current_sub_folder.get_FolderName().equals("Practise Sub Folder"))
               {
                  
                   selected_sub_folder=current_sub_folder;
               }
           }
          
            System.out.println(""+selected_sub_folder.get_FolderName());
           
            //now store data of document in  this sub folder only
           
            //get the data from local system
           
            File file=new File("C:\\Users\\tempuser.TIT-JAVA-040\\Downloads\\content navigator.pdf");
           
            try
            {
               
                FileInputStream input_data=new FileInputStream(file);
               
                //get the instance for documnet to store above input data
               
                Document doc=Factory.Document.createInstance(object_store, null);
               
                //set trasfering method
               
                ContentTransfer content_transfer=Factory.ContentTransfer.createInstance();
               
                //set the data to this content transfer
               
                content_transfer.setCaptureSource(input_data);
               
                //set the mime type
               
                content_transfer.set_ContentType("application/pdf");
               
                //set a name for document
               
                content_transfer.set_RetrievalName("shashi practice");
               
                //create a content element list and add this content transfer data to the list
               
                ContentElementList content_element_list=Factory.ContentElement.createList();
               
                content_element_list.add(content_transfer);
               
                //add the content elements to the current document
                doc.set_ContentElements(content_element_list);
               
                doc.getProperties().putValue("DocumentTitle","shashi practice" );
               
                doc.set_MimeType("application/pdf");
               
                //check in document
               
                doc.checkin(AutoClassify.AUTO_CLASSIFY, CheckinType.MINOR_VERSION);
               
                doc.save(RefreshMode.REFRESH);
               
                //set the current document under the sub folder
                ReferentialContainmentRelationship file1 = selected_sub_folder.file(doc, AutoUniqueName.AUTO_UNIQUE, "shashi practice", DefineSecurityParentage.DEFINE_SECURITY_PARENTAGE);
               
                file1.save(RefreshMode.REFRESH);
               
                System.out.println("Your document saved ");
           
            }
            catch(Exception e)
            {
                System.out.println(""+e.getLocalizedMessage());
            }
           
        }
       
    }
   
}

----------------------------------
EngineConnection.java

import  com.filenet.api.core.*;
import com.filenet.api.util.UserContext;
import javax.security.auth.Subject;

public class EngineConnection {

   
    Connection giveConnection()
    {
    
       
        String url="http://192.168.2.22:9080/wsi/FNCEWS40MTOM";
       
        Connection connection = Factory.Connection.getConnection(url);
       
        Subject subject =UserContext.createSubject(connection, "p8admin", "ecm@dmin1", null);
       
       
        UserContext context=UserContext.get();
       
        context.pushSubject(subject);
       
       
        if(connection!=null)
           
            return connection;
       
        return connection;
       
       
               
    }
   
}