/*
    * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/servlets/FileServlet.java,v 1.29 2006/03/18 16:01:07 hkollmann Exp $
    * $Revision: 1.29 $
    * $Date: 2006/03/18 16:01:07 $
    *
    * DbForms - a Rapid Application Development Framework
    * Copyright (C) 2001 Joachim Peer <joepeer@excite.com>
    *
    * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   */
  
  package org.dbforms.servlets;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.dbforms.servlets.base.AbstractServletBase;
  
  import org.dbforms.config.DbFormsConfig;
  import org.dbforms.config.DbFormsConfigRegistry;
  import org.dbforms.config.Field;
  import org.dbforms.config.FieldTypes;
  import org.dbforms.config.Table;
  
  import org.dbforms.util.SqlUtil;
  import org.dbforms.util.StringUtil;
  import org.dbforms.util.Util;
  import org.dbforms.util.FileHolder;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  
  import javax.servlet.ServletException;
  import javax.servlet.ServletOutputStream;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  /***
   * #fixme - add appropriate exception-handling..
   * 
   * @author joe peer
   */
  public class FileServlet extends AbstractServletBase {
  	// logging category for this class
  	private static Log logCat = LogFactory.getLog(FileServlet.class.getName());
  
  	/***
  	 * Process the HTTP Get request
  	 * 
  	 * @param request
  	 *            Description of the Parameter
  	 * @param response
  	 *            Description of the Parameter
  	 * 
  	 * @exception ServletException
  	 *                Description of the Exception
  	 * @exception IOException
  	 *                Description of the Exception
  	 */
  	public void process(HttpServletRequest request, HttpServletResponse response)
  			throws ServletException, IOException {
  
  		// take Config-Object from application context - this object should have
  		// been
  		// initalized by Config-Servlet on Webapp/server-startup!
  		DbFormsConfig config = null;
  		try {
  			config = DbFormsConfigRegistry.instance().lookup();
  		} catch (Exception e) {
  			logCat.error(e);
  			throw new ServletException(e);
  		}
  
  		try {
  			String tf = request.getParameter("tf");
  			String keyValuesStr = request.getParameter("keyval");
  			if (!Util.isNull(keyValuesStr) && !("null".equals(keyValuesStr))) {
  
  				int tableId = Integer.parseInt(StringUtil.getEmbeddedString(tf,
  						0, '_'));
  				Table table = config.getTable(tableId);
  				int fieldId = Integer.parseInt(StringUtil.getEmbeddedString(tf,
 						1, '_'));
 				Field field = table.getField(fieldId);
 
 				StringBuffer queryBuf = new StringBuffer();
 				String dbConnectionName = request.getParameter("invname_"
 						+ tableId);
 				Connection con = config.getConnection(dbConnectionName);
 
 				// JPeer 03/2004 - optional parameter
 				String nameField = request.getParameter("nf");
 
 				InputStream is = null;
 				String fileName = null;
 
 				queryBuf.append("SELECT ");
 				queryBuf.append(field.getName());
 
 				if (nameField != null) {
 					queryBuf.append(", ");
 					queryBuf.append(nameField);
 				}
 
 				queryBuf.append(" FROM ");
 				queryBuf.append(table.getQueryFrom());
 				queryBuf.append(" WHERE ");
 				queryBuf.append(table.getWhereClauseForKeyFields(keyValuesStr));
 
 				// example: SELECT imageNameField FROM myTable WHERE myTable.key
 				// = ?
 				logCat.info("::doGet - query is [" + queryBuf + "]");
 
 				PreparedStatement ps = con
 						.prepareStatement(queryBuf.toString());
 				table.populateWhereClauseWithKeyFields(keyValuesStr, ps, 1);
 
 				ResultSet rs = ps.executeQuery();
 
 				if (rs.next()) {
 					// use the filesystem;
 					if (field.getType() == FieldTypes.DISKBLOB) {
 						fileName = rs.getString(1);
 						String directory = field.getDirectory();
 						try {
 							directory = DbFormsConfigRegistry.instance().lookup().replaceVariables(directory);
 						} catch (Exception ex) {
 							logCat
 									.error(
 											"::doGet  - error replacing REALPATH on diskblob directory",
 											ex);
 						}
 						is = SqlUtil.readDiskBlob(fileName, directory, request
 								.getParameter("defaultValue"));
 					}
 					// use the rdbms;
 					else if (field.getType() == FieldTypes.BLOB) {
 						// if no fileholder is used (new BLOB model)
 						if (nameField != null) {
 							fileName = rs.getString(2);
 							is = SqlUtil.readDbFieldBlob(rs);
 						} else {
 							FileHolder fh = SqlUtil.readFileHolderBlob(rs);
 							is = fh.getInputStreamFromBuffer();
 							fileName = fh.getFileName();
 						}
 					}
 				} else {
 					logCat.info("::doGet - we have got no result using query "
 							+ queryBuf);
 				}
 
 				if (is != null) {
 					writeToClient(request, response, fileName, is);
 				}
 
 				SqlUtil.closeConnection(con);
 			}
 		} catch (SQLException sqle) {
 			logCat.error("::doGet - SQL exception", sqle);
 		}
 	}
 
 	/***
 	 * Write the content of the input file to the client.
 	 * 
 	 * @param request
 	 *            DOCUMENT ME!
 	 * @param response
 	 *            Description of the Parameter
 	 * @param fileName
 	 *            Description of the Parameter
 	 * @param is
 	 *            Description of the Parameter
 	 * 
 	 * @exception IOException
 	 *                Description of the Exception
 	 */
 	private void writeToClient(HttpServletRequest request,
 			HttpServletResponse response, String fileName, InputStream is)
 			throws IOException {
 		String contentType = request.getSession().getServletContext()
 				.getMimeType(fileName);
 		logCat.info("::writeToClient- writing to client:" + fileName + " ct="
 				+ contentType);
 
 		if (!Util.isNull(contentType)) {
 			response.setContentType(contentType);
 		}
 
 		response.setHeader("Cache-control", "private"); // w/o this MSIE fails
 
 		// to "Open" the file
 		response.setHeader("Content-Disposition", "attachment; fileName=\""
 				+ fileName + "\"");
 
 		ServletOutputStream out = response.getOutputStream();
 		byte[] b = new byte[1024];
 		int read;
 
 		while ((read = is.read(b)) != -1)
 			out.write(b, 0, read);
 
 		out.close();
 	}
 }