文件下载

//下载
public void downFile() throws IOException{
String fileName = request.getParameter("fileName");
fileName = URLDecoder.decode(fileName, "UTF-8");
response.setCharacterEncoding("UTF-8");
   boolean isOnLine = false;
   Properties commonPro = new Properties();
   String path = "config/common.properties";
   InputStream is = AndroidVersionMainupdateAction.class.getClassLoader().getResourceAsStream(path);
   commonPro.load(is);
   String pt = commonPro.getProperty("filePath");
   String filePath =pt+"\\"+fileName;
System.out.println("filePath"+filePath); 
File f = new File(filePath); 
if (!f.exists()) { 
response.sendError(404, "File not found!"); 
return; 
}  
BufferedInputStream br = new BufferedInputStream(new FileInputStream(f)); 
byte[] buf = new byte[1024]; 
int len = 0; 
response.reset(); //非常重要
        if(isOnLine){ //在线打开方式
            URL u = new URL("file:///"+filePath);
            response.setContentType(u.openConnection().getContentType());
            response.setHeader("Content-Disposition", "inline; filename="+(f.getName()).getBytes("gbk"));
        //文件名应该编码成UTF-8
        }
        else{ //纯下载方式
            response.setContentType("application/x-msdownload"); 
            response.setHeader("Content-Disposition", "attachment; filename=" + java.net.URLEncoder.encode(f.getName(),"UTF-8")); 
        }
OutputStream out = response.getOutputStream(); 
while ((len = br.read(buf)) > 0) out.write(buf, 0, len); 
br.close(); 
out.close(); 
}