Java 8 新特性对比

前景

找到子集  or 兄弟

多规格商品  

 private List<Commodity> toCommodityRepresentation(List<Commodity> commodities){
        List<CommodityStock> stocks=commodityStockMapper.findByIds(commodities);

        List<Commodity> commodityList = commodities.stream().filter(w -> w.getItemId() != 0).map(w -> {
　　　　　　　　//同itemid  不同ID
            List<CommodityStock> goodsItems = stocks.stream().filter(localW -> localW.getId() != w.getId() && localW.getItemId() == w.getItemId()).collect(Collectors.toList());
            if(goodsItems.size() > 1){
                logger.error("数据错误，同一条码最多只能存在两种规格,scp_item id:{}",w.getId());
            }
            if(goodsItems.size() > 0){
                w.setCommodityStock(goodsItems.get(0));
            }
            return w;
        }).collect(Collectors.toList());

        return commodityList;
｝

 private List<Commodity> toCommodityRepresentation(List<Commodity> commodities){

　　　　List<CommodityStock> stocks=commodityStockMapper.findByIds(commodities)；

        Map<Long,CommodityStock> boxMap=new HashMap<>();
        Map<Long,CommodityStock> scatterMap=new HashMap<>();

        for (int i = 0; i < stocks.size(); i++) {
            CommodityStock stock=stocks.get(i);
            int bulk=stock.getBulk();
            long itemId=stock.getItemId();
            if(bulk==0){
                boxMap.put(itemId,stock);
            }else{
                scatterMap.put(itemId,stock);
            }
        }
        for (int i = 0; i <commodities.size() ; i++) {
            Commodity commodity=commodities.get(i);
            int bulk=commodity.getBulk();
            long itemId=commodity.getItemId();
            if(bulk==0 && !scatterMap.isEmpty() && scatterMap.containsKey(itemId)){
                commodity.setCommodityStock(scatterMap.get(itemId));
            }
            if(bulk==1 && !boxMap.isEmpty() && boxMap.containsKey(itemId)){
                commodity.setCommodityStock(boxMap.get(itemId));
            }
        }
        return  commodities;
｝