分页1-5之间跳转代码

boolean isAdd = request.getParameter("add") == null?false:true;boolean isDec = request.getParameter("dec") == null?false:true;int num = 1;String pNum = request.getParameter("num");if(pNum !=null){  if(isAdd) {      if(Integer.valueOf(pNum)<5)           num = Integer.valueOf(pNum) + 1;      else          num = Integer.valueOf(pNum);         }   if(isDec) {      if(Integer.valueOf(pNum)>1)           num = Integer.valueOf(pNum) - 1;      else          num = Integer.valueOf(pNum); }