| <html><head> |
| <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> |
| <title>2.7. Direct Rendering</title><link rel="stylesheet" href="css/stylesheet.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.75.0"><link rel="home" href="index.html" title="Apache Click"><link rel="up" href="ch02.html" title="Chapter 2. Pages"><link rel="prev" href="ch02s06.html" title="2.6. Page Templating"><link rel="next" href="ch02s08.html" title="2.8. Stateful Pages"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">2.7. Direct Rendering</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch02s06.html">Prev</a> </td><th width="60%" align="center">Chapter 2. Pages</th><td width="20%" align="right"> <a accesskey="n" href="ch02s08.html">Next</a></td></tr></table><hr></div><div class="sect1" title="2.7. Direct Rendering"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="page-direct-rendering"></a>2.7. Direct Rendering</h2></div></div></div><p>Pages support a direct rendering mode where you can render directly |
| to the servlet response and bypass the page template rendering. This is |
| useful for scenarios where you want to render non HTML content to the |
| response, such as a PDF or Excel document. To do this: |
| </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p> get the servlet response object</p></li><li class="listitem"><p> set the content type on the response</p></li><li class="listitem"><p> get the response output stream</p></li><li class="listitem"><p> write to the output stream</p></li><li class="listitem"><p> close the output stream</p></li><li class="listitem"><p> set the page path to null to inform the ClickServlet that |
| rendering has been completed</p></li></ul></div><p>A direct rendering example is provided below. |
| </p><pre class="programlisting"><span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** |
| * Render the Java source file as "text/plain". |
| * |
| * @see Page#onGet() |
| */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">void</span> onGet() { |
| String filename = .. |
| |
| HttpServletResponse response = getContext().getResponse(); |
| |
| response.setContentType(<span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="str">"text/plain"</span>); |
| response.setHeader(<span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="str">"Pragma"</span>, <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="str">"no-cache"</span>); |
| |
| ServletContext context = getContext().getServletContext(); |
| |
| InputStream inputStream = null; |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">try</span> { |
| inputStream = context.getResourceAsStream(filename); |
| |
| PrintWriter writer = response.getWriter(); |
| |
| BufferedReader reader = <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">new</span> BufferedReader(<span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">new</span> InputStreamReader(inputStream)); |
| |
| String line = reader.readLine(); |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">while</span> (line != null) { |
| writer.println(line); |
| line = reader.readLine(); |
| } |
| |
| setPath(null); |
| |
| } <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">catch</span> (IOException ioe) { |
| ioe.printStackTrace(); |
| |
| } <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">finally</span> { |
| ClickUtils.close(inputStream); |
| } |
| }</pre></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch02s06.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch02.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch02s08.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">2.6. Page Templating </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 2.8. Stateful Pages</td></tr></table></div></body></html> |
