servlet 常用指令

一.设置响应内容类型

     response.setContentType("text/html;charset=UTF-8");

二.设置请求的字符编码

     request.setCharacterEncoding("utf-8");

三.获取调度器

    RequestDispatcher rd = request.getRequestDispatcher("/index.jsp");

    rd.forward(request, response);    内部跳转

   response.sendRedirect("add.jsp");   重定向

response.sendRedirect(request.getContextPath()+"/WEB-INF/page/index.jsp");

==

request.getRequestDispatcher("page/index.jsp").forward(request,response);

==

PrintWriter writer = response.getWriter();

writer.write("<script>alert('账号密码错误！');window.location.href='login.jsp';</script>");

writer.flush();

writer.close();

 四.获取前台上下文

   HttpSession session = request.getSession();