动态JSP页生成静态HTML的方法

三叶草

本文实例讲述了动态JSP页生成静态HTML的方法。分享给大家供大家参考。具体如下：
具体实现：
利用Filter的过滤功能把*.jsp过滤出来，判断是否存在对应的.html文件，如果不存在对应的.html文件，则将其内容读出写入指定的.html文件，再跳转到对应的.html即可。如果存在对应的.html文件，则直接跳转到对应的.html即可。

代码：
JspFilter.java：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class JspFilter implements Filter {
  public void destroy() {
  // TODO 自动生成方法存根
  }
  public void doFilter(ServletRequest request, ServletResponse response,
    FilterChain chain) throws IOException, ServletException {
  HttpServletRequest hreq = (HttpServletRequest) request;
  HttpServletResponse hresp = (HttpServletResponse) response;
  String name = hreq.getRequestURL().substring(
      hreq.getRequestURL().lastIndexOf("/") + 1,
      hreq.getRequestURL().lastIndexOf("."));
  if (hreq.getRequestURL().indexOf(".jsp") != -1 && (null == hreq.getParameter("type") || hreq.getParameter("type").equals(""))) {
    hresp.sendRedirect(hreq.getContextPath()+"/conversion?name="+hreq.getRequestURL());
    return ;
  }
  chain.doFilter(request, response);
  }
  public void init(FilterConfig arg0) throws ServletException {
  // TODO 自动生成方法存根
  }
}

ConversionServlet.java：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ConversionServlet extends HttpServlet {
  public ConversionServlet () {
  super();
  }
  public void destroy() {
  super.destroy(); // Just puts "destroy" string in log
  // Put your code here
  }
  public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  //----获取请求的URL
  String reqTarget = request.getParameter("name");
  //----指定对应JSP的HTML名称
  String name = reqTarget.substring(reqTarget.lastIndexOf("/") + 1,reqTarget.lastIndexOf("."));
  //---判断是否存在对应的HTML文件
  File file = new File(request.getRealPath("/") + name + ".html");
  if (!file.exists()) {  //--------如果不存在对应的HTML文件
    try {
    file.createNewFile();  //--------创建HTML文件
    //-------将JSP的内容写入对应的HTML文件内
    InputStream in;
    StringBuffer sb = new StringBuffer("");
    //----注意这里，不能直接访问请求的URL，如果直接访问的话，会陷入死循环
    URL url = new java.net.URL(reqTarget.toString()+"?type=11");
    HttpURLConnection connection = (HttpURLConnection) url
      .openConnection();
    connection.setRequestProperty("User-Agent", "Mozilla/4.0");
    connection.connect();
    in = connection.getInputStream();
    java.io.BufferedReader breader = new BufferedReader(
      new InputStreamReader(in, "GBK"));
    String currentLine;
    FileOutputStream fos = new FileOutputStream(file);
    while ((currentLine = breader.readLine()) != null) {
      sb.append(currentLine);
      fos.write(currentLine.getBytes());
    }
    if (null != breader)
      breader.close();
    if (null != fos)
      fos.close();
    //---------------转到与JSP对应的HTML页
    response.sendRedirect(request.getContextPath()+"/"+name + ".html");
    } catch (Exception e) {
    e.printStackTrace();
    }
  }else{
    //----------如果存在指定的HTML，直接跳转到指定的HTML页
    response.sendRedirect(request.getContextPath()+"/"+name + ".html");
  }
  }
  public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
  doGet(request, response);
  }
  public void init() throws ServletException {
  // Put your code here
  }
}

WEB.XML配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
  xmlns="https://java.sun.com/xml/ns/j2ee"
  xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="https://java.sun.com/xml/ns/j2ee
  https://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
 <filter>
  <filter-name>jspfilter</filter-name>
  <filter-class>com.beanutil.JspFilter</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>jspfilter</filter-name>
  <url-pattern>*.jsp</url-pattern>
 </filter-mapping>
 <servlet>
  <servlet-name>conversion</servlet-name>
  <servlet-class>com.beanutil.ConversionServlet </servlet-class>
 </servlet>
 <servlet-mapping>
  <servlet-name>conversion</servlet-name>
  <url-pattern>/conversion</url-pattern>
 </servlet-mapping>
</web-app>

希望本文所述对大家的JSP程序设计有所帮助。