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);
 }