Servlet实现控制文件下载速度

 long speed =1024*100L;//限制下载速度为100k/s,
long current=0;
ServletOutputStream out = resp.getOutputStream();

File file =new File("xxxxxx");
FileInputStream in = new FileInputStream(file);
byte[]temp=new byte[1024];
int i;
long startTime=System.currentTimeMillis();
while((i=in.read(temp))!=-1){
current=current+i;
out.write(temp);
if(current>speed){
startPause(startTime+1000);
current=0;
startTime=System.currentTimeMillis();
}
}
in.close();
}

private void startPause(long time){
while(true){
if(System.currentTimeMillis()>time){
break;
}
}
}