動態JSP頁生成靜態HTML的方法

本文實例講述了動態JSP頁生成靜態HTML的方法。分享給大家供大家參考。具體如下：

具體實現：

利用Filter的過濾功能把*.jsp過濾出來，判斷是否存在對應的.html文件，如果不存在對應的.html文件，則將其內容讀出寫入指定的.html文件，再跳轉到對應的.html即可。如果存在對應的.html文件，則直接跳轉到對應的.html即可。
 
代碼：

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 自動生成方法存根
  }
  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 自動生成方法存根
  }
}

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();
    //----獲取請求的URL
    String reqTarget = request.getParameter("name");
    //----指定對應JSP的HTML名稱
    String name = reqTarget.substring(reqTarget.lastIndexOf("/") + 1,reqTarget.lastIndexOf("."));
    //---判斷是否存在對應的HTML文件
    File file = new File(request.getRealPath("/") + name + ".html");
    if (!file.exists()) {  //--------如果不存在對應的HTML文件
      try {
        file.createNewFile();  //--------創建HTML文件
        //-------將JSP的內容寫入對應的HTML文件內
        InputStream in;
        StringBuffer sb = new StringBuffer("");
      //----注意這裡，不能直接訪問請求的URL，如果直接訪問的話，會陷入死循環
        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();
        //---------------轉到與JSP對應的HTML頁
        response.sendRedirect(request.getContextPath()+"/"+name + ".html");
      } catch (Exception e) {
        e.printStackTrace();
      }
    }else{
      //----------如果存在指定的HTML，直接跳轉到指定的HTML頁
      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="http://java.sun.com/xml/ns/j2ee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
  http://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>

希望本文所述對大家的JSP程序設計有所幫助。