1)스크립트 이용
<% if (디비결과값) { %>
<script>location.href = "login.jsp"; </script>
<% } else { %>
<script>alert('정보없음'); window.history.back(); </script>
<% } %>
-----------------------------------------------------------------
2)response.sendRedirect
<% if (a == null) {
response.sendRedirect("admin.jsp");
} else {
response.sendRedirect("login.jsp");
}
%>
------------------------------------------------------------------
3)forward
<% if (a == null) { %>
<jsp:forward page="admin.jsp"/>
<% } else { %>
<jsp:forward page="login.jsp"/>
<% } %>
------------------------------------------------------------------
4)meta 태그 이용
<META http-equiv=refresh content="0;url=admin.jsp">