Servlet中的文件下载

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("application/jar");

ServletContext ctx = getServletContext();
InputStream is = ctx.getResourceAsStream("/bookCode.jar");

int read = 0;
byte[] bytes = new byte[1024];

OutputStream os = response.getOutputStream();
while ((read = is.read(bytes)) != -1) {
os.write(bytes, 0, read);
}
os.flush();
os.close();
}