【expires】设置缓存时间

public class ServletDemo14 extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

String data="test expires cache";
long expires=System.currentTimeMillis()+1*24*60*60*1000;
response.setDateHeader("expires", expires);
response.getWriter().write(data);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}

}