ImportServlet.java

package edu.ucsf.mousedatabase.servlets;

import java.io.IOException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;


import edu.ucsf.mousedatabase.HTMLGeneration;
import edu.ucsf.mousedatabase.HTMLUtilities;
import edu.ucsf.mousedatabase.Log;
import edu.ucsf.mousedatabase.dataimport.ImportHandler;



public class ImportServlet extends HttpServlet {

  public static final String fileFieldName = "datafile";
  public static final String importDefinitionIdFieldName = "importType";
  public static final String importDescriptionFieldName = "importDescription";
  private static final long serialVersionUID = 1L;

  public void init(ServletConfig config) throws ServletException {
    super.init(config);

  }
  @SuppressWarnings("rawtypes")
  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    ServletFileUpload uploadHandler = new ServletFileUpload(new DiskFileItemFactory ());
    try {
      /*
       * Parse the request
       */
      List items = uploadHandler.parseRequest(request);
      Iterator itr = items.iterator();

      final HashMap<String,String> parameters = new HashMap<String, String>();
      FileItem dataFile = null;
      int importDefinitionId = -1;
      while(itr.hasNext())
      {
        FileItem item = (FileItem) itr.next();
        if(item.isFormField())
        {
          parameters.put(item.getFieldName(), item.getString());
          //Log.Info("Input field Name = "+item.getFieldName()+", Value = "+item.getString());
          if (item.getFieldName().equals(importDefinitionIdFieldName))
          {
            importDefinitionId = Integer.parseInt(item.getString());
          }
        }
        else
        {
          if (item.getFieldName().equals(fileFieldName))
          {
            dataFile = item;
          }
        }

      }
      String[] charsetsToTry = new String[]{"UTF-16","UTF-8","ASCII"};
      //Charset encoding = detectEncoding(dataFile);
      ArrayList<HashMap<String,String>> csvData = null;

      for (String charsetName : charsetsToTry)
      {
        csvData = HTMLUtilities.readCSVFileFromStream(dataFile,Charset.forName(charsetName));
        if (csvData.size() > 0)
        {
          Log.Info("ImportServlet: Detected charset for " + dataFile.getName() + ": " + charsetName);
          break;
        }
      }

      final ArrayList<HashMap<String,String>> finalData = csvData;
      final int finalDefinitionId = importDefinitionId;

      Thread t = new Thread(new Runnable(){
        @Override
        public void run() {
          try
          {
            ImportHandler.handleImport(finalData, finalDefinitionId,parameters);
          }
          catch (Exception e)
          {
              Log.Error("Unhandled exception handling import.",e);
          }
        }});
      t.start();
      //redirect to results jsp results page for reportID

      response.sendRedirect(HTMLGeneration.adminRoot + "ImportStatus.jsp");

    }
    catch(FileUploadException ex)
    {
      log("Error encountered while parsing the request",ex);
      response.sendRedirect(HTMLGeneration.siteRoot + "error.jsp");
    }
    catch(Exception ex)
    {
      log("Error encountered while uploading file",ex);
      throw new ServletException(ex);
    }

  }



//  private Charset detectEncoding(FileItem dataFile)
//  {
//    // TODO try several, looking at first few characters for dictionary words
//    return Charset.forName("UTF-16");
//  }





}