txt文件下载,很多人问过,但是...

<%@ page contentType="text/html; charset=gb2312"%><%@page import="java.io.*"%><%

    String filename = "";

    if (request.getParameter("filename") != null) {

        filename =     request.getParameter("filename");

    }

    String name = filename.substring(filename.lastIndexOf("/") + 1);

    //response.setContentType("application/msword");

    response.setContentType("application/x-msdownload"); 

    response.setHeader("Content-disposition","attachment; filename="+name);

    

    BufferedInputStream bis = null;

    BufferedOutputStream bos = null;

    try {

        bis = new BufferedInputStream(new FileInputStream(getServletContext().getRealPath("" + filename)));

        bos = new BufferedOutputStream(response.getOutputStream());



        byte[] buff = new byte[2048];

        int bytesRead;



        while(-1 != (bytesRead = bis.read(buff, 0, buff.length))) {

            bos.write(buff,0,bytesRead);

        }



    } catch(final IOException e) {

        System.out.println ( "出现IOException." + e );

  	} catch(final IllegalStateException e) {

    	System.out.println ( "出现IllegalStateException." + e );

	}finally {

        if (bis != null)

            bis.close();

        if (bos != null)

        {

        	bos.flush();

        	bos.close();

        	bos=null;

        }

    }

	response.flushBuffer();

    out.clear();

    out = pageContext.pushBody();

   

%>