利用Java生成静态HMTL页面的方法收集
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利用Java生成静态HMTL页面的方法收集
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利用Java生成靜態(tài)HMTL頁面的方法收集
生成靜態(tài)頁面技術(shù)解決方案之一轉(zhuǎn)載者前言:這是一個全面的jsp動態(tài)頁面靜態(tài)化方案,本站的帖子靜態(tài)化方案將借鑒這篇帖子中方法。向[url]http://www.agilejava.org[/url]的single的共享精神致敬。
轉(zhuǎn)帖正文:
?????? 相信很多人都希望自己的頁面越快越好,最好是能靜態(tài)的,提高客戶訪問速度。也便于搜索引擎搜索。所以,就希望我們的動態(tài)讀取數(shù)據(jù)庫的頁面,盡可能的生成靜態(tài)頁面。一下系列文章,介紹一下個人的解決方案。
????? 本系列將介紹個人的一種方法,在不改變原來jsp文件的基礎(chǔ)上,只需要加入少量的代碼,就讓你的新聞發(fā)布系統(tǒng),很容易就完全變成靜態(tài)的頁面。
??????????? 本文假設(shè)你是用java開發(fā)的web動態(tài)頁面。
?????????? 第一步,加入servlet.代碼如下。
????? public class ToHtml extends HttpServlet {
?????? public void service(HttpServletRequest request, HttpServletResponse response)
???????? throws ServletException, IOException {
??????? String url = "";
??????? String name = "";
??????? ServletContext sc = getServletContext();
??????? String file_name = request.getParameter("file_name");// 你要訪問的jsp文件名,如index,不包括擴展名
??????? // 則你訪問這個servlet時加參數(shù).如[url]http://localhost/test/toHtml?file_name=index[/url]
??????? url = "/" + file_name + ".jsf";// 你要生成的頁面的文件名。我的擴展名為jsf .
??????? name = ConfConstants.CONTEXT_PATH+"\\"+ file_name + ".htm";// 這是生成的html文件名,如index.htm.文件名字與源文件名相同。擴展名為htm
????? //ConfConstants.CONTEXT_PATH為你的應(yīng)用的上下文路徑。
??????? RequestDispatcher rd = sc.getRequestDispatcher(url);
??????? final ByteArrayOutputStream ōs = new ByteArrayOutputStream();
??????? final ServletOutputStream stream = new ServletOutputStream() {
???????? public void write(byte[] data, int offset, int length) {
????????? os.write(data, offset, length);
???????? }
???????? public void write(int b) throws IOException {
????????? os.write(b);
???????? }
??????? };
??????? final PrintWriter pw = new PrintWriter(new OutputStreamWriter(os));
??????? HttpServletResponse rep = new HttpServletResponseWrapper(response) {
???????? public ServletOutputStream getOutputStream() {
????????? return stream;
???????? }
???????? public PrintWriter getWriter() {
????????? return pw;
???????? }
??????? };
??????? rd.include(request, rep);
??????? pw.flush();
??????? FileOutputStream fos = new FileOutputStream(name); // 把jsp輸出的內(nèi)容寫到xxx.htm
??????? os.writeTo(fos);
??????? fos.close();
??????? PrintWriter ōut = response.getWriter();
??????? out
????????? .print("<p align=center><font size=3 color=red>頁面已經(jīng)成功生成!single<br>[url]http://www.agilejava.org/space/?[/url] 233</font></p>");
?????? }
????? }
????? 第二步、配置你的web.xml
?????? <servlet>
??????? <servlet-name>toHtml</servlet-name>
??????? <servlet-class>mj.util.html.ToHtml</servlet-class>//你的servlet的類。
?????? </servlet>
?????? <servlet-mapping>
??????? <servlet-name>toHtml</servlet-name>
??????? <url-pattern>/toHtml</url-pattern>
?????? </servlet-mapping>
????? 第三步、運行servlet。如:[url]http://localhost:8080/test/toHtml?file_name=index[/url]
??????
????? OK,這就在你的test項目的根目錄下,生成了一個index.htm的靜態(tài)文件。
??????
????? 局限性:本文只能生成一個文件!訪問一次,生成一個文件。并且生成的文件名也與原來的文件名相同。
????? 比較適合主頁生成靜態(tài)頁面。
??????
????? 本系列的后續(xù)文章將解決更多的問題。使之在新聞發(fā)布系統(tǒng)中,很容易就集成應(yīng)用。
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生成靜態(tài)頁面技術(shù)解決方案之二
??????????? 注意:轉(zhuǎn)貼本文,請加上本文鏈接[url]http://www.agilejava.org/space/?233/action_viewspace_itemid_21.html?[/url]
?????????? 在上一篇文章中,生成靜態(tài)頁面,是有一定的局限性的。生成主頁是很方便,但要生成二級頁面,就不方便了。
???????????? 本文假設(shè)一個新聞發(fā)布系統(tǒng)。希望后臺發(fā)布的,前臺顯示的是靜態(tài)的文檔。這就涉及,主頁要是靜態(tài)的,同時二級列表也是靜態(tài)的,新聞內(nèi)容也是靜態(tài)的。也就是 說, 在發(fā)布一篇新聞的時候,可能涉及到三個地方生成靜態(tài)文檔。并且,要生成一個網(wǎng)頁,必須訪問一個servlet。在大量生成靜態(tài)網(wǎng)頁的時候,
??????????? 以下方法,可以解決這些問題。
????????? 一、加入一下servelet
????????? /**
?????????? * @file_name 文件名及文件之后的參數(shù).最好為a.jsf?fileId=aaaa
?????????? * @path 文件所在的路徑.相對于根目錄而言的.
?????????? * @realName文件要保存的名字
?????????? * @realPath文件要保存的真實路徑。默認與文件所在的目錄相同。
?????????? */
????????? public class ToHtmlPath extends HttpServlet {
?????????? public void service(HttpServletRequest request, HttpServletResponse response)
???????????? throws ServletException, IOException {
??????????? String url = "";
??????????? String name = "";
??????????? ServletContext sc = getServletContext();
??????????? String file_name = request.getParameter("file_name");// 你要訪問的jsp文件,如news.jsf。
??????????? // file_name如:fileDetail.jsf?fileId=56.要是有參數(shù), 只有一個參數(shù)。并且以參數(shù)名作為文件名。
??????????? String realName = request.getParameter("realName");// 要保存的文件名。如aaa;注意可以沒有這個參數(shù)。
??????????? String path = request.getParameter("path");// 你要訪問的jsp文件路徑。如news。注意可以沒有這個參數(shù)。
??????????? String realPath = request.getParameter("realPath");// 你要保存的文件路徑,如htmlNews.注意可以沒有這個參數(shù)。
??????????? // 下面確定要保存的文件名字。
??????????? if (realName == null || realName == "") {
???????????? int a = 0;
???????????? a = file_name.indexOf("=") + 1;
???????????? realName = file_name.substring(a);
???????????? if (realName.indexOf(".")>0) {
????????????? realName = file_name.substring(0, file_name.indexOf("."));
???????????? }
??????????? }
??????????? // 下面構(gòu)造要訪問的頁面。
??????????? if (path == null || path == "") {
???????????? url = "/" + file_name;// 這是你要生成HTML的jsp文件,如
??????????? } else {
???????????? url = "/" + path + "/" + file_name;// 這是你要生成HTML的jsp文件,如
??????????? }
??????????? // 下面構(gòu)造要保存的文件名,及路徑。
??????????? // 1、如果有realPath,則保存在realPath下。
??????????? // 2、如果有path則保存在path下。
??????????? // 3、否則,保存在根目錄下。
??????????? if (realPath == null || realPath == "") {
???????????? if (path == null || path == "") {
????????????? name = ConfConstants.CONTEXT_PATH + "\\" + realName + ".htm";// 這是生成的html文件名,如index.htm.說明: ConfConstants.CONTEXT_PATH為你的上下文路徑。
???????????? } else {
????????????? name = ConfConstants.CONTEXT_PATH + "\\" + path + "\\"
??????????????? + realName + ".htm";// 這是生成的html文件名,如index.htm.
???????????? }
??????????? } else {
???????????? name = ConfConstants.CONTEXT_PATH + "\\" + realPath + "\\"
?????????????? + realName + ".htm";// 這是生成的html文件名,如index.htm.
??????????? }
??????????? // 訪問請求的頁面,并生成指定的文件。
??????????? RequestDispatcher rd = sc.getRequestDispatcher(url);
??????????? final ByteArrayOutputStream ōs = new ByteArrayOutputStream();
??????????? final ServletOutputStream stream = new ServletOutputStream() {
???????????? public void write(byte[] data, int offset, int length) {
????????????? os.write(data, offset, length);
???????????? }
???????????? public void write(int b) throws IOException {
????????????? os.write(b);
???????????? }
??????????? };
??????????? final PrintWriter pw = new PrintWriter(new OutputStreamWriter(os));
??????????? HttpServletResponse rep = new HttpServletResponseWrapper(response) {
???????????? public ServletOutputStream getOutputStream() {
????????????? return stream;
???????????? }
???????????? public PrintWriter getWriter() {
????????????? return pw;
???????????? }
??????????? };
??????????? rd.include(request, rep);
??????????? pw.flush();
??????????? FileOutputStream fos = new FileOutputStream(name); // 把jsp輸出的內(nèi)容寫到xxx.htm
??????????? os.writeTo(fos);
??????????? fos.close();
??????????? PrintWriter ōut = response.getWriter();
??????????? out.print("<p align=center><font size=3 color=red>success!</font></p>");
?????????? }
????????? }
??????????
????????? 二、在web.xml里面配置你的servlet
?????????? <servlet>
??????????? <servlet-name>toHtmlPath</servlet-name>
??????????? <servlet-class>mj.util.html.ToHtmlPath</servlet-class>
?????????? </servlet>
?????????? <servlet-mapping>
??????????? <servlet-name>toHtmlPath</servlet-name>
??????????? <url-pattern>/toHtmlPath</url-pattern>
?????????? </servlet-mapping>
????????? 三、寫一個通用的方法, 供調(diào)用。
????????? public class CallHtml {
?????????? public static void callOnePage(String fileName, String path,
???????????? String realName, String realPath) {
??????????? try {
???????????? String str = "http://localhost:8080/test/toHtmlPath?file_name="
?????????????? + fileName + "&&path=" + path + "&&realName=" + realName
?????????????? + "&&realPath=" + realPath;
???????????? int httpResult;
???????????? URL url = new URL(str);
???????????? URLConnection connection = url.openConnection();
???????????? connection.connect();
???????????? HttpURLConnection httpURLConnection = (HttpURLConnection) connection;
???????????? httpResult = httpURLConnection.getResponseCode();
???????????? if (httpResult != HttpURLConnection.HTTP_OK) {
????????????? System.out.println("沒有連接成功");
???????????? } else {
????????????? System.out.println("連接成功了 ");
???????????? }
??????????? } catch (Exception e) {
???????????? // TODO: handle exception
??????????? }
?????????? }
????????? //這個方法適當(dāng)重載,就可以省去一些參數(shù)傳遞。
????????? }
????????? 四、在你的新聞發(fā)布save時,調(diào)用方法。
????????? 1、CallHtml.callOnePage("info.jsf?file_id=aaa",news,"", "");//將在news目錄下生成一個aaa.htm的靜態(tài)文件
????????? 2、CallHtml.callOnePage("newsList.jsf",news,"", "");//將在news目錄下生成一個newsList.htm的靜態(tài)文件,顯示最新的新聞。
????????? 3、CallHtml.callOnePage("index.jsf","","", "");//生成主頁。
????????? 好了,這就保持了,主頁、列表、新聞內(nèi)容都是最新的靜態(tài)頁面了。
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一個實現(xiàn)將動態(tài)頁面轉(zhuǎn)為靜態(tài)的方案
1.前言
為了能深入淺出的理解這個框架的由來,我們首先來了解一下JSP解析器將我們寫的JSP代碼轉(zhuǎn)換成的JAVA文件的內(nèi)容。
下面是一個JSP文件test.jsp
經(jīng)過TOMCAT轉(zhuǎn)換出的JAVA文件test$jsp.java內(nèi)容如下:
package org.apache.jsp;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import org.apache.jasper.runtime.*;
public class test$jsp extends HttpJspBase {
??? static {
??? }
??? public testOutRedir$jsp( ) {
??? }
??? private static boolean _jspx_inited = false;
??? public final void _jspx_init() throws org.apache.jasper.runtime.JspException {
??? }
??? public void _jspService(HttpServletRequest request, HttpServletResponse? response)
??????? throws java.io.IOException, ServletException {
??????? JspFactory _jspxFactory = null;
??????? PageContext pageContext = null;
??????? HttpSession session = null;
??????? ServletContext application = null;
??????? ServletConfig config = null;
??????? JspWriter out = null;
??????? Object page = this;
??????? String? _value = null;
??????? try {
??????????? if (_jspx_inited == false) {
??????????????? synchronized (this) {
??????????????????? if (_jspx_inited == false) {
??????????????????????? _jspx_init();
??????????????????????? _jspx_inited = true;
??????????????????? }
??????????????? }
??????????? }
??????????? _jspxFactory = JspFactory.getDefaultFactory();
??????????? response.setContentType(text/html;charset=GB2312);
??????????? pageContext = _jspxFactory.getPageContext(this, request, response,
??????????????????????????? , true, 8192, true);
??????????? application = pageContext.getServletContext();
??????????? config = pageContext.getServletConfig();
??????????? session = pageContext.getSession();
??????????? out = pageContext.getOut();
??????????????? //為了節(jié)省篇幅,我刪除了解釋器添加的注釋
??????????????? out.write(\r\n);
//上一句是由于后面的換行產(chǎn)生的
??????????????? out.write();
??????????????? out.write(\r\n\r\n\r\n\r\n);
??????????????? out.print( 輸出 );
??????????????? out.write(\r\n\r\n\r\n\r\n);
??????? } catch (Throwable t) {
??????????? if (out != null && out.getBufferSize() != 0)
??????????????? out.clearBuffer();
??????????? if (pageContext != null) pageContext.handlePageException(t);
??????? } finally {
??????????? if (_jspxFactory != null) _jspxFactory.releasePageContext(pageContext);
??????? }
??? }
}
從上面的代碼中可以清晰的看到JSP內(nèi)建的幾個對象(out、request、response、session、pageContext、application、config、page)是怎么產(chǎn)生的,懂servlet的朋友一看就能明白。
下面重點理解一下out對象,它被聲明為JspWriter類型,JspWriter是一個抽象類,在包javax.servlet.jsp中可以找到它的定義。
abstract public class javax.servlet.jsp.JspWriter extends java.io.Writer{
?????? final public static int NO_BUFFER = 0;
?????? final public static int DEFAULT_BUFFER = -1;
?????? final public static int UNBOUNDED_BUFFER = -2;
?????? protected int bufferSize;
?????? protected Boolean autoFlush;
?????? protected javax.servlet.jsp.JspWriter(int arg1, boolean arg2);
??????
??? abstract public void newLine() throws IOException ;
??? abstract public void print(boolean arg0) throws IOException ;
??? abstract public void print(char arg0) throws IOException ;
??? abstract public void print(int arg0) throws IOException ;
??? abstract public void print(long arg0) throws IOException ;
??? abstract public void print(float arg0) throws IOException ;
??? abstract public void print(double arg0) throws IOException ;
??? abstract public void print(char[] arg0) throws IOException ;
??? abstract public void print(String arg0) throws IOException ;
??? abstract public void print(Object arg0) throws IOException ;
??? abstract public void println() throws IOException ;
??? abstract public void println(boolean arg0) throws IOException ;
??? abstract public void println(char arg0) throws IOException ;
??? abstract public void println(int arg0) throws IOException ;
??? abstract public void println(long arg0) throws IOException ;
??? abstract public void println(float arg0) throws IOException ;
??? abstract public void println(double arg0) throws IOException ;
??? abstract public void println(char[] arg0) throws IOException ;
??? abstract public void println(String arg0) throws IOException ;
??? abtract public void println(Object arg0) throws IOException ;
??? abstract public void clear() throws IOException ;
??? abstract public void clearBuffer() throws IOException ;
??? abstract public void flush() throws IOException ;
??? abstract public void close() throws IOException ;
??? public int getBufferSize() ;
??? abstract public int getRemaining() ;
??? public boolean isAutoFlush() ;
}
我相信當(dāng)我寫到這里你可能已經(jīng)知道我想怎么做了。是的,來個偷天換日,繼承JspWriter類,然后實現(xiàn)其定義的虛函數(shù),然后把out變量替換成你自己實現(xiàn)的類的實例就ok了。
2.實現(xiàn)替換
假設(shè)
3.更新問題
下面就討論一下如何更新生成靜態(tài)文件,其實從上面實現(xiàn)中你可以看到,很簡單的就是將生成的靜態(tài)文件刪除即可,至于什么時候刪除,要看你的需求了。我能想到的幾種情況如下
當(dāng)用來生成頁面的數(shù)據(jù)更新時
如果不需要很提供時時的數(shù)據(jù)可以定時更新
永遠不更新
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JSP生成靜態(tài)HTML頁面范例
先建立一個模本頁面:template.htm
<Html>
<head>
<title>###title###</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<LINK href="../Css.css" rel=stylesheet type=text/css>
</head>
<body>
<table width="500" border="0" align="center" cellpadding="0" cellspacing="2">
<tr>
<td align="center">###title###</td>
</tr>
<tr>
<td align="center">作者:###author### </td>
</tr>
<tr>
<td>###content###
</td>
</tr>
</table>
</body>
</html>
=========================================
再寫一個jsp頁面: buildhtml.jsp
<%@ page contentType="text/html; charset=gb2312" import="Java.util.*,java.io.*"%>
<%
try{
String title="jsp生成靜態(tài)html文件";
String content="小樣,還搞不定你?";
String editer="webjxcom";
String filePath = "";
filePath = request.getRealPath("/")+"template.htm";
out.print(filePath);
String templateContent="";
FileInputStream fileinputstream = new FileInputStream(filePath);//讀取模塊文件
int lenght = fileinputstream.available();
byte bytes[] = new byte[lenght];
fileinputstream.read(bytes);
fileinputstream.close();
templateContent = new String(bytes);
out.print(templateContent);
templateContent=templateContent.replaceAll("###title###",title);
templateContent=templateContent.replaceAll("###content###",content);
templateContent=templateContent.replaceAll("###author###",editer);//替換掉模塊中相應(yīng)的地方
out.print(templateContent);
// 根據(jù)時間得文件名
Calendar calendar = Calendar.getInstance();
String fileame = String.valueOf(calendar.getTimeInMillis()) +".html";
fileame = request.getRealPath("/")+fileame;//生成的html文件保存路徑
FileOutputStream fileoutputstream = new FileOutputStream(fileame);//建立文件輸出流
out.print("文件輸出路徑:<br>");
out.print(fileame);
byte tag_bytes[] = templateContent.getBytes();
fileoutputstream.write(tag_bytes);
fileoutputstream.close();
}
catch(Exception e){
out.print(e.toString());
}
%>
-------------------------------------------
mport java.io.*;
import java.net.*;
public class Tools {
??? final static Object lock = new Object();
??? public static void makeHtml(String page, String filePath)...{
??????? makeHtml(page,filePath,"UTF-8");
??? }
??? public static void makeHtml(String page, String filePath,String chartset) {
??????? synchronized (lock) {
??????????? HttpURLConnection huc = null;
??????????? BufferedReader br = null;
??????????? BufferedWriter bw = null;
??????????? try {
??????????????? 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();
?????????????????? }
??????????????? }
??????????? }catch (Exception e) {
??????????????? e.printStackTrace();
??????????? }finally {
??????????????? try {
??????????????????? br.close();
??????????????????? bw.close();
??????????????????? huc.disconnect();
??????????????? }catch (Exception e) {
??????????????????? e.printStackTrace();
??????????????? }
??????????? }
??????? }
}
轉(zhuǎn)載于:https://blog.51cto.com/topstar/138331
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