JSP生成HTML页面，以提高访问效率

    通常是采用JSP生成内容可变的网站页面，这种访问方式就意味着每访问一次页面会调用后台重新生成HTML页面，这样就造成了效率低下。

    今天遇到一种技术，也是目前很多网站系统都采用的技术：先将JSP页面生成的HTML缓存起来，IE用户访问这些HTML页面就比访问JSP效率高很多。而这些HTML页面只需要通过后台调用方法更新，就能实现对前台被请求页面的更新。

    方法大致是通过HttpURLConnection类请求特定的页面资源并获取流，将流写入文件流生成.HTML文件。

 

下面贴一下JAVA代码:

 package com.hndoc.util;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.net.HttpURLConnection;import java.net.URL;public class ContentOperation {final static Object lock = new Object();final static Object jsLock = new Object();/** * 将JSP转为HTML * @param page 　用于生成html页面的jsp的路径 * @param filePath 生成html文件的路径 * @param chartset 字符串编码 * @throws IOException */public static void makeHtml(String page, String filePath, String chartset)throws IOException {synchronized (lock) {HttpURLConnection huc = null;BufferedReader br = null;BufferedWriter bw = null;huc = (HttpURLConnection) new URL(page).openConnection();System.setProperty("sun.net.client.defaultConnectTimeout", "30000");System.setProperty("sun.net.client.defaultReadTimeout", "30000");huc.connect();InputStream stream = huc.getInputStream();bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(filePath), chartset));br = new BufferedReader(new InputStreamReader(stream, chartset));String line;while ((line = br.readLine()) != null) {if (line.trim().length() > 0) {bw.write(line);bw.newLine();}}br.close();bw.close();huc.disconnect();}}/** * 产生栏目对应的JS脚本 * @param str * @param filePath 文件路径 * @param chartset　字符编码 * @throws IOException */public static void makeJs(String str , String filePath, String chartset)throws IOException {synchronized (jsLock) {BufferedWriter bw = null;bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(filePath), chartset));if ((str!=null) && (str.trim().length() > 0)) {bw.write(str);}bw.close();}}}

 

    在生成HTML文件后，页面整体框架不会变，但可以通过JS控制页面数据。之后改变JS文件即可更改页面显示的数据。

 

JAVASCRIPT代码:

var _article_array_1101=[{"title":"/u7F8E/u672F/u54C1/u7ECF/u8425/u5355/u4F4D/u5907/u6848/u60C5/u51B5/u767B/u8BB0/u8868","substring_title":"/u7F8E/u672F/u54C1/u7ECF/u8425/u5355/u4F4D/u5907/u6848/u60C5/u51B5/u767B/u8BB0/u8868","url":"OaOnline.do?action=OaOnlineDetail&oa_id=000000000000000001","pub_time":"2009-02-09"},{"title":"/u8BBE/u7ACB/u4E92/u8054/u7F51/u6587/u5316/u5355/u4F4D/u7533/u8BF7","substring_title":"/u8BBE/u7ACB/u4E92/u8054/u7F51/u6587/u5316/u5355/u4F4D/u7533/u8BF7","url":"OaOnline.do?action=OaOnlineDetail&oa_id=000000000000000002","pub_time":"2009-02-09"},{"title":"/u6E56/u5357/u6F14/u51FA/u7ECF/u7EAA/u673A/u6784/u7533/u62A5/u8868","substring_title":"/u6E56/u5357/u6F14/u51FA/u7ECF/u7EAA/u673A/u6784/u7533/u62A5/u8868","url":"OaOnline.do?action=OaOnlineDetail&oa_id=000000000000000003","pub_time":"2009-02-09"},{"title":"/u5916/u56FD/u6587/u827A/u8868/u6F14/u56E2/u4F53/u6216/u4E2A/u4EBA/u6765/u6E58/u8FDB/u884C/u8425/u4E1A/u6027/u6F14/u51FA/u7533/u62A5/u8868","substring_title":"/u5916/u56FD/u6587/u827A/u8868/u6F14/u56E2/u4F53/u6216/u4E2A/u4EBA/u6765/u6E58/u8FDB...","url":"OaOnline.do?action=OaOnlineDetail&oa_id=000000000000000004","pub_time":"2009-02-09"},{"title":"/u7F8E/u672F/u54C1/u7ECF/u8425/u5355/u4F4D/u5907/u6848/u60C5/u51B5/u767B/u8BB0/u8868","substring_title":"/u7F8E/u672F/u54C1/u7ECF/u8425/u5355/u4F4D/u5907/u6848/u60C5/u51B5/u767B/u8BB0/u8868","url":"OaOnline.do?action=OaOnlineDetail&oa_id=000000000000000005","pub_time":"2009-02-09"},{"title":"/u4E2D/u5916/u5408/u8D44/u3001/u4E2D/u5916/u5408/u4F5C/u6F14/u51FA/u573A/u6240/u7ECF/u8425/u5355/u4F4D/u5E74/u5EA6/u62A5/u8868","substring_title":"/u4E2D/u5916/u5408/u8D44/u3001/u4E2D/u5916/u5408/u4F5C/u6F14/u51FA/u573A/u6240/u7ECF...","url":"OaOnline.do?action=OaOnlineDetail&oa_id=000000000000000006","pub_time":"2009-02-09"},{"title":"/u8BBE/u7ACB/u4E92/u8054/u7F51/u6587/u5316/u5355/u4F4D/u7533/u8BF7","substring_title":"/u8BBE/u7ACB/u4E92/u8054/u7F51/u6587/u5316/u5355/u4F4D/u7533/u8BF7","url":"OaOnline.do?action=OaOnlineDetail&oa_id=000000000000000007","pub_time":"2009-02-09"}]

 

HTML代码:

 <script src="./contentjs/portal/1101.js"></script><script>if("undefined" != typeof _article_array_1101)for(i=0;i<7;i++){var dd=_article_array_1101[i];if("undefined" == typeof dd){break;}document.write("<li><a href='"+dd['url']+"' target='_blank' >·"+dd['substring_title']);document.write("</a></li>");}</script>   

 

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    后台调用方法，生成装载数据的JS文件，即可完成页面数据更新。