public void downLoad(String filePath,HttpServletResponse response,boolean isOnLine)
throws Exception{
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){ //在線打開方式
URL u = new URL("file:///"+filePath); 
response.setContentType(u.openConnection().getContentType()); 
response.setHeader("Content-Disposition", "inline; filename="+f.getName()); 
//文件名應該編碼成UTF-8
}
else{ //純下載方式
response.setContentType("application/x-msdownload"); 
response.setHeader("Content-Disposition", "attachment; filename=" + f.getName()); 
}
OutputStream out = response.getOutputStream(); 
while((len = br.read(buf)) 〉0)
out.write(buf,0,len); 
br.close(); 
out.close(); 
}