<%
  String address=request.getParameter("address");
   if(address!=null)
    {
     out.write( "<script language='javascript'>");
      out.write( "alert('我要跳转');");
       out.write( "window.location='"+address+"';");
        out.write( "</script>");
         }
%>

解决方案 »

  1.   

    window.location.href = "your address";
      

  2.   

    <%
        String address=request.getParameter("address");
        if(address!=null)
        {
            out.write( "<script language='javascript'>");
            out.write( "alert('我要跳转');");
            out.write( "window.location.href="+address+";");
            out.write( "</script>");
        }
    %>
      

  3.   

    <%
      String address=request.getParameter("address");
       if(num!=null){%>
         <script language='javascript'>
            alert("我要跳转");
           window.location.href="<%=address%>";
         </script>
    <%}%>
      

  4.   

    同意楼上,稍微改动
    <%
      String address=request.getParameter("address");
       if(num!=null && address!=null){%>
         <script language="javascript">
            alert("我要跳转")
           window.location.href="<%=address%>"
         </script>
    <%}%>