switch (goodsItem.getProductType()) { case 1://爆品 GoodsExplosive explosive = null; List<GoodsExplosive> explosives = new GoodsExplosive().selectList(new LambdaUpdateWrapper<GoodsExplosive>() .eq(GoodsExplosive::getGoodsItemId, goodsItem.getId()) .orderByDesc(GoodsExplosive::getId)); if (explosives.size() > 1) { explosive = explosives.stream().sorted(Comparator.comparing(GoodsExplosive::getGroundingState, (s1, s2) -> { if (s1.equals(s2)) { return 0; } else if (s1 == 1 || s2 == 5) { return -1; } else if (s1 == 5 || s2 == 1) { return 1; } else if (s1 == 2) { return -1; } else if (s2 == 2) { return 1; } else if (s1 == 0) { return -1; } else { return 1; } })).findFirst().orElse(null); } else { explosive = explosives.size() == 1 ? explosives.get(0) : explosive; } map.put("productData", explosive); break; case 2://优品 GoodsExcellent excellent = null; List<GoodsExcellent> excellents = new GoodsExcellent().selectList(new LambdaUpdateWrapper<GoodsExcellent>() .eq(GoodsExcellent::getGoodsItemId, goodsItem.getId()) .orderByDesc(GoodsExcellent::getId)); if (excellents.size() > 1) { excellent = excellents.stream().sorted(Comparator.comparing(GoodsExcellent::getGroundingState, (s1, s2) -> { if (s1.equals(s2)) { return 0; } else if (s1 == 1 || s2 == 5) { return -1; } else if (s1 == 5 || s2 == 1) { return 1; } else if (s1 == 2) { return -1; } else if (s2 == 2) { return 1; } else if (s1 == 0) { return -1; } else { return 1; } })).findFirst().orElse(null); } else { excellent = excellents.size() == 1 ? excellents.get(0) : excellent; } map.put("productData", excellent); break; case 3://现货 GoodsEnjoy enjoy = null; List<GoodsEnjoy> enjoys = new GoodsEnjoy().selectList(new LambdaUpdateWrapper<GoodsEnjoy>() .eq(GoodsEnjoy::getGoodsItemId, goodsItem.getId()) .orderByDesc(GoodsEnjoy::getId)); if (enjoys.size() > 1) { enjoy = enjoys.stream().sorted(Comparator.comparing(GoodsEnjoy::getGroundingState, (s1, s2) -> { if (s1.equals(s2)) { return 0; } else if (s1 == 1 || s2 == 5) { return -1; } else if (s1 == 5 || s2 == 1) { return 1 } else if (s1 == 2) { return -1; } else if (s2 == 2) { return 1; } else if (s1 == 0) { return -1; } else { return 1; } })).findFirst().orElse(null); } else { enjoy = enjoys.size() == 1 ? enjoys.get(0) : enjoy; } map.put("productData", enjoy); break; default: throw new IllegalStateException("Unexpected value: " + goodsItem.getProductType()); }怎么优化

可以考虑将 switch 语句拆分成三个方法，分别处理不同商品类型的逻辑，从而降低代码的重复度和复杂度。例如：

private GoodsExplosive getExplosiveData(GoodsItem goodsItem) {
    List<GoodsExplosive> explosives = new GoodsExplosive().selectList(new LambdaUpdateWrapper<GoodsExplosive>()
            .eq(GoodsExplosive::getGoodsItemId, goodsItem.getId())
            .orderByDesc(GoodsExplosive::getId));
    if (explosives.isEmpty()) {
        return null;
    }
    if (explosives.size() == 1) {
        return explosives.get(0);
    }
    return explosives.stream()
            .sorted(Comparator.comparing(GoodsExplosive::getGroundingState, (s1, s2) -> {
                if (s1.equals(s2)) {
                    return 0;
                } else if (s1 == 1 || s2 == 5) {
                    return -1;
                } else if (s1 == 5 || s2 == 1) {
                    return 1;
                } else if (s1 == 2) {
                    return -1;
                } else if (s2 == 2) {
                    return 1;
                } else if (s1 == 0) {
                    return -1;
                } else {
                    return 1;
                }
            }))
            .findFirst()
            .orElse(null);
}

private GoodsExcellent getExcellentData(GoodsItem goodsItem) {
    List<GoodsExcellent> excellents = new GoodsExcellent().selectList(new LambdaUpdateWrapper<GoodsExcellent>()
            .eq(GoodsExcellent::getGoodsItemId, goodsItem.getId())
            .orderByDesc(GoodsExcellent::getId));
    if (excellents.isEmpty()) {
        return null;
    }
    if (excellents.size() == 1) {
        return excellents.get(0);
    }
    return excellents.stream()
            .sorted(Comparator.comparing(GoodsExcellent::getGroundingState, (s1, s2) -> {
                if (s1.equals(s2)) {
                    return 0;
                } else if (s1 == 1 || s2 == 5) {
                    return -1;
                } else if (s1 == 5 || s2 == 1) {
                    return 1;
                } else if (s1 == 2) {
                    return -1;
                } else if (s2 == 2) {
                    return 1;
                } else if (s1 == 0) {
                    return -1;
                } else {
                    return 1;
                }
            }))
            .findFirst()
            .orElse(null);
}

private GoodsEnjoy getEnjoyData(GoodsItem goodsItem) {
    List<GoodsEnjoy> enjoys = new GoodsEnjoy().selectList(new LambdaUpdateWrapper<GoodsEnjoy>()
            .eq(GoodsEnjoy::getGoodsItemId, goodsItem.getId())
            .orderByDesc(GoodsEnjoy::getId));
    if (enjoys.isEmpty()) {
        return null;
    }
    if (enjoys.size() == 1) {
        return enjoys.get(0);
    }
    return enjoys.stream()
            .sorted(Comparator.comparing(GoodsEnjoy::getGroundingState, (s1, s2) -> {
                if (s1.equals(s2)) {
                    return 0;
                } else if (s1 == 1 || s2 == 5) {
                    return -1;
                } else if (s1 == 5 || s2 == 1) {
                    return 1;
                } else if (s1 == 2) {
                    return -1;
                } else if (s2 == 2) {
                    return 1;
                } else if (s1 == 0) {
                    return -1;
                } else {
                    return 1;
                }
            }))
            .findFirst()
            .orElse(null);
}

然后在原来的 switch 语句中，通过调用这三个方法来获取不同商品类型的数据：

switch (goodsItem.getProductType()) {
    case 1:
        map.put("productData", getExplosiveData(goodsItem));
        break;
    case 2:
        map.put("productData", getExcellentData(goodsItem));
        break;
    case 3:
        map.put("productData", getEnjoyData(goodsItem));
        break;
    default:
        throw new IllegalStateException("Unexpected value: " + goodsItem.getProductType());
}

这样可以使代码更加清晰、简洁，并且易于维护。