用servlet 来验证是否为空呀!我没做过!通常是在页面用JavaScript 不过试一下看看行不行
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
response.setContentType("text/html;charset=GB2312");
PrintWriter out=response.getWriter();
String ID=request.getParameter("ID");
if(ID==null)
{
out.println("<html>");
out.println("<head><title></title></head>");
out.println("<body bgcolor=\"#ffffff\">");
out.println("<p>请输入ID。5秒钟之后将回到主页面</p>");
out.println("</body></html>");
response.setHeader("Refresh","5;URL=原本的登陆页面.jsp");
}
if(ID!=null)
{
this.getServletContext().getRequestDispatcher("/新页面.jsp").forward(request,response);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
response.setContentType("text/html;charset=GB2312");
PrintWriter out=response.getWriter();
String ID=request.getParameter("ID");
if(ID==null)
{
out.println("<html>");
out.println("<head><title></title></head>");
out.println("<body bgcolor=\"#ffffff\">");
out.println("<p>请输入ID。5秒钟之后将回到主页面</p>");
out.println("</body></html>");
response.setHeader("Refresh","5;URL=原本的登陆页面.jsp");
}
if(ID!=null)
{
this.getServletContext().getRequestDispatcher("/新页面.jsp").forward(request,response);
}
}
解决方案 »
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