Servlet
, ServletConfig
public class ConcatServlet extends HttpServlet
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 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"></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 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 304 NOT Modified responses if appropriate. This means that when not in development mode, the servlet must be restarted before changed content will be served.
Constructor | Description |
---|---|
ConcatServlet() |
Modifier and Type | Method | Description |
---|---|---|
protected void |
doGet(HttpServletRequest request,
HttpServletResponse response) |
|
protected long |
getLastModified(HttpServletRequest req) |
|
void |
init() |
destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log
public void init() throws ServletException
init
in class GenericServlet
ServletException
protected long getLastModified(HttpServletRequest req)
getLastModified
in class HttpServlet
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, java.io.IOException
doGet
in class HttpServlet
ServletException
java.io.IOException
Copyright © 1995–2018 Webtide. All rights reserved.