org.mortbay.servlet.ConcatServlet Maven / Gradle / Ivy
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//========================================================================
//Copyright 2004-2008 Mort Bay Consulting Pty. Ltd.
//------------------------------------------------------------------------
//Licensed under the Apache License, Version 2.0 (the "License");
//you may not use this file except in compliance with the License.
//You may obtain a copy of the License at
//http://www.apache.org/licenses/LICENSE-2.0
//Unless required by applicable law or agreed to in writing, software
//distributed under the License is distributed on an "AS IS" BASIS,
//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//See the License for the specific language governing permissions and
//limitations under the License.
//========================================================================
package org.mortbay.servlet;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/* ------------------------------------------------------------ */
/** Concatenation Servlet
* This servlet may be used to concatenate multiple resources into
* a single response. It is intended to be used to load multiple
* javascript or css files, but may be used for any content of the
* same mime type that can be meaningfully concatenated.
*
* The servlet uses {@link RequestDispatcher#include(javax.servlet.ServletRequest, javax.servlet.ServletResponse)}
* to combine the requested content, so dynamically generated content
* may be combined (Eg engine.js for DWR).
*
* The servlet uses parameter names of the query string as resource names
* relative to the context root. So these script tags:
*
* <script type="text/javascript" src="../js/behaviour.js"></script>
* <script type="text/javascript" src="../js/ajax.js&/chat/chat.js"></script>
* <script type="text/javascript" src="../chat/chat.js"></script>
*
can be replaced with the single tag (with the ConcatServlet mapped to /concat):
*
* <script type="text/javascript" src="../concat?/js/behaviour.js&/js/ajax.js&/chat/chat.js"></script>
*
* The {@link ServletContext#getMimeType(String)} method is used to determine the
* mime type of each resource. If the types of all resources do not match, then a 415
* UNSUPPORTED_MEDIA_TYPE error is returned.
*
* If the init parameter "development" is set to "true" then the servlet will run in
* development mode and the content will be concatenated on every request. Otherwise
* the init time of the servlet is used as the lastModifiedTime of the combined content
* and If-Modified-Since requests are handled with 206 NOT Modified responses if
* appropriate. This means that when not in development mode, the servlet must be
* restarted before changed content will be served.
*
* @author gregw
*
*/
public class ConcatServlet extends HttpServlet
{
boolean _development;
long _lastModified;
ServletContext _context;
/* ------------------------------------------------------------ */
public void init() throws ServletException
{
_lastModified=System.currentTimeMillis();
_context=getServletContext();
_development="true".equals(getInitParameter("development"));
}
/* ------------------------------------------------------------ */
/*
* @return The start time of the servlet unless in development mode, in which case -1 is returned.
*/
protected long getLastModified(HttpServletRequest req)
{
return _development?-1:_lastModified;
}
/* ------------------------------------------------------------ */
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{
String q=req.getQueryString();
if (q==null)
{
resp.sendError(HttpServletResponse.SC_NO_CONTENT);
return;
}
String[] parts = q.split("\\&");
String type=null;
for (int i=0;i