jsp首页静态化

应用背景： 网站首页是网站访问频度最大的页面，同样这个页面承载的信息也是最多与广泛的。而这些信息对及时行要求也不是特别高（一般一天一个更新）。这种情况下应用缓存静态化比较适合。

代码流程：

[img]http://dl.iteye.com/upload/attachment/0063/6425/fc2e4e71-0237-3258-aeab-9167dae99878.jpg[/img]


关键代码：
本代码以jsp为例，其实还可以用freemarker等模板语言，但本人认为页面静态化属于后期优化工作，目前jsp应用要比freemarker要广泛，所以jsp更具有意义。

protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException
	{
		//实际中这个路径会根据参数在一定规则的计算下得到，保证其唯一性
		File f = new File("/htmls/test.html");
		if (!f.exists())
		{
			//加工数据，实际中会调用service
			request.setAttribute("name",
					"测试");
			String content = JspUtil.getHtml(request, response,
					"/index.jsp");
			FileUtil.save(content, "/htmls", null, "test.html");
		}
		StringBuffer sb = new StringBuffer();
		FileReader fr = new FileReader(f);
		BufferedReader br = new BufferedReader(fr);
		String str = null;
		while ((str = br.readLine()) != null)
		{
			sb.append(str);
		}
		fr.close();
		br.close();
		response.setCharacterEncoding("utf-8");
		PrintWriter out = response.getWriter();
		out.print(sb.toString());
		out.flush();
	}

public class JspUtil
{

	public static String getHtml(HttpServletRequest request,
			HttpServletResponse response, String jsp) throws ServletException,
			IOException
	{

		FileCaptureResponseWrapper fileCaptureResponseWrapper = new FileCaptureResponseWrapper(response);

		request.getRequestDispatcher(jsp).forward(request,
				fileCaptureResponseWrapper);

		return fileCaptureResponseWrapper.toString();

	}

	public static class FileCaptureResponseWrapper extends
			HttpServletResponseWrapper
	{

		private CharArrayWriter writer;

		public FileCaptureResponseWrapper(HttpServletResponse response)
		{
			super(response);
			this.writer = new CharArrayWriter();
		}

		public PrintWriter getWriter()
		{
			return new PrintWriter(writer);
		}

		@Override
		public String toString()
		{

			String result = writer.toString();
			writer.flush();
			writer.close();
			return result;
		}

	}

}

后话：得到html代码后，可以存储到磁盘上，同样也可以应用缓存框架等工具，具体可以看具体情况而定。至于更新，可以设置时间更新，比如一天一次。同样也可以手动更新，比如编辑有一个即时更新首页的需要，这种情况最好手动更新啦。具体做法就是把存储的html数据清空就可以了！