Redis缓存--购物车，首页

购物车添加物品

@Override
    public boolean addBook(TShopcar tShopcar) {
        int num = tShopcar.getNum();
        //在查询Mysql之前先从redis中去查，redis中查询出的结果为空再到mysql去查,然后将mysql中查询的结果缓存到redis中
        String rbook=redisDao.hget("car"+tShopcar.getUid(),tShopcar.getBid().toString());
        if (rbook==null||rbook.equals("nil")){//如果redis中不存在该商品那么在mysql中去查，查完之后将结果添加到redis中
            TShopcar bookInCar=tShopcarMapper.selectSelective(tShopcar);
            if (bookInCar!=null){
                //说明购物车中已经存在该类商品，此时只需要更新这个商品的数量
                tShopcar.setNum(num+bookInCar.getNum());
                tShopcarMapper.updateNum(tShopcar);
                bookInCar.setNum(num+bookInCar.getNum());
                redisDao.hset("car"+tShopcar.getUid(),tShopcar.getBid().toString(), JSON.toJSONString(bookInCar));
            }
            else{//购物车中不存在该商品，直接添加
                tShopcar.setNum(num);
                List shopList=tShopcarMapper.selectCarByUid(tShopcar.getUid());
                int count=shopList.size();
                if (count>= Constants.CAR_MAX_SIZE){//购物车中的商品数量已达上限
                    return false;
                }
                tShopcarMapper.insert(tShopcar);
            }
        }
        else {//将从redis中查出来的结果更新到mysql中
            //将rbook转成TShopCar对象
            TShopcar bookInCar=JSON.parseObject(rbook,TShopcar.class);
            tShopcar.setNum(num+bookInCar.getNum());
            tShopcarMapper.updateNum(tShopcar);
            bookInCar.setNum(num+bookInCar.getNum());
            redisDao.hset("car"+tShopcar.getUid(),tShopcar.getBid().toString(), JSON.toJSONString(bookInCar));
        }
        return true;

    }

首页缓存分类信息，因为分类基本不变

@Override
	public List selectAll() {
		String typeListStr=redisDao.get("typeList");
		System.out.println("---------typeList------"+typeListStr);
		if (typeListStr==null||typeListStr.equals("")){//查询数据库
			List typeList=typeMapper.selectAll();
			System.out.println(JSONArray.toJSONString(typeList));
			redisDao.set("typeList",JSONArray.toJSONString(typeList));
			return typeList;
		}
		else {
		List typeList=JSONObject.parseArray(typeListStr,TType.class);
		return  typeList;
		}
	}