解决教学平台上文件中存在无扩展名ＢＵＧ的办法

public void configHandler(Handlers me)
{
me.add(new XssHandler());
}

package com.demo.common.config;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jfinal.handler.Handler;

/**
* 统一XSS处理
*/
public class XssHandler extends Handler
{

@Override
public void handle(String target, HttpServletRequest request,
HttpServletResponse response, boolean[] isHandled)
{

System.out.println(target);

if(target.equals("/css/2222"))
{
String abc=target.replaceAll("/", "\\\\"); //这里是为什么要加４个???\\\\

String path="C:\\Users\\Administrator\\Desktop\\jfinal_demo\\WebRoot"+abc;
try {
response.setHeader("Content-Type","application/octet-stream");
response.setHeader("content-disposition", "attachment;filename=" +
URLEncoder.encode("2222", "UTF-8"));

InputStream in = null ;
OutputStream out = null ;
try
{
in = new FileInputStream(path); //获取文件的流
int len = 0;
byte buf[] = new byte[1024];//缓存作用
out = response.getOutputStream();//输出流
while( (len = in.read(buf)) > 0 ) //切忌这后面不能加 分号 ”;“
{
out.write(buf, 0, len);//向客户端输出，实际是把数据存放在response中，然后web服务器再去response中读取
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
if(in!=null)
{
try{
in.close();
}catch(IOException e){
e.printStackTrace();
}
}

if(out!=null)
{
try{
out.close();
}catch(IOException e){
e.printStackTrace();
}
}
}

} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//System.out.println("target -> " + target);
// 对于非静态文件，和非指定排除的url实现过滤
/*
if (!target.contains(".") && !target.startsWith(exclude))
{
System.out.println("target -> " + target);
request = new HttpServletRequestWrapper(request);
}
nextHandler.handle(target, request, response, isHandled);*/
}
}