response对象
response.setContentType("text/html;charset=utf-8");
out.println("<h1>response内置对象</h1>");
out.println("<hr>");
//out.flush();
PrintWriter outer=response.getWriter(); // 优先于内置对象out输出
outer.println("大家好，我是response对象生成的输出流outer对象");
// response.sendRedirect("exercise.jsp");
request.getRequestDispatcher("do.jsp").forward(request, response);