java servlet生成html

package com.html;

import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

public class HtmlDemo extends HttpServlet
{
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException
{
   this.doPost(req, resp);
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException
{
   RequestDispatcher dispatcher = this.getServletContext().getRequestDispatcher("/index.jsp");
   final ByteArrayOutputStream byteos = new ByteArrayOutputStream();
   final ServletOutputStream stream = new ServletOutputStream()
   { 
    //只是处理字节流，而PrintWriter则是处理字符流,和   
    public void write(byte[] data, int offset, int length)
    {
     byteos.write(data, offset, length);
    } 
    public void write(int b) throws IOException
    {
     byteos.write(b);
    }
   };
   final PrintWriter printw= new PrintWriter(new OutputStreamWriter(byteos,"UTF-8")); //进行编码转换,当输出流从比特流转换为字符流的时候设置才是有效的。   
   HttpServletResponse rep = new HttpServletResponseWrapper(resp)
   {
    @Override
    public ServletOutputStream getOutputStream() {
     return stream;
    }

    @Override
    public PrintWriter getWriter() {
     return printw;
    }
   };
   dispatcher.include(req, rep);
   printw.flush();
   FileOutputStream fileos = new FileOutputStream("/index_jsp.html", false); // 把jsp输出的内容写到xxx.htm   
   byteos.writeTo(fileos);
   fileos.close();
}
}