实现文件页面不打开，直接下载

<%@page import="java.util.*"%>
<%@page import="java.io.*"%>
<%@page import="java.net.*"%>
<%
String filename = "";
if (request.getParameter("file") != null) {
filename = request.getParameter("file");
}
response.setContentType("application/msword");
response.setHeader("Content-disposition","attachment; filename="+filename);

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 );
} finally {
if (bis != null)
bis.close();
if (bos != null)
bos.close();
}
return;
%>