Article Directory
1 Product list
1.1 Interface definition
Transfer parameters
categoryId(非必传，子类目的商品也要查出来)
pageNum(default=1)
pageSize(default=10)
return value
{
"status": 0,
"data": {
"pageNum": 1,
"pageSize": 10,
"size": 2,
"orderBy": null,
"startRow": 1,
"endRow": 2,
"total": 2,
"pages": 1,
"list": [
{
"id": 1,
"categoryId": 3,
"name": "iphone7",
"subtitle": "双十一促销",
"mainImage": "mainimage.jpg",
"status":1,
"price": 7199.22
},
{
"id": 2,
"categoryId": 2,
"name": "oppo R8",
"subtitle": "oppo促销进行中",
"mainImage": "mainimage.jpg",
"status":1,
"price": 2999.11
}
],
"firstPage": 1,
"prePage": 0,
"nextPage": 0,
"lastPage": 1,
"isFirstPage": true,
"isLastPage": true,
"hasPreviousPage": false,
"hasNextPage": false,
"navigatePages": 8,
"navigatepageNums": [
1
]
}
}
1.2 Code writing
1.2.1 controller
@GetMapping("/products")
public ResponseVo<PageInfo> list(@RequestParam(required = false) Integer categoryId,
@RequestParam(required = false, defaultValue = "1") Integer pageNum,
@RequestParam(required = false, defaultValue = "10") Integer pageSize) {
return productService.list(categoryId, pageNum, pageSize);
}
1.2.2 Query subcategories and subcategories
Improve:
@Override
public void findSubCategoryId(Integer id, Set<Integer> resultSet) {
List<Category> categories = categoryMapper.selectAll();
findSubCategoryId(id, resultSet, categories);
}
private void findSubCategoryId(Integer id, Set<Integer> resultSet, List<Category> categories) {
for (Category category : categories) {
if (category.getParentId().equals(id)) {
resultSet.add(category.getId());
findSubCategoryId(category.getId(), resultSet, categories);
}
}
}
1.2.3service
@Override
public ResponseVo<PageInfo> list(Integer categoryId, Integer pageNum, Integer pageSize) {
Set<Integer> categoryIdSet = new HashSet<>();
if (categoryId != null) {
categoryService.findSubCategoryId(categoryId, categoryIdSet);
categoryIdSet.add(categoryId);
}
PageHelper.startPage(pageNum, pageSize);
List<Product> productList = productMapper.selectByCategoryIdSet(categoryIdSet);
List<ProductVo> productVoList = productList.stream()
.map(e -> {
ProductVo productVo = new ProductVo();
BeanUtils.copyProperties(e, productVo);
return productVo;
})
.collect(Collectors.toList());
PageInfo pageInfo = new PageInfo<>(productList);
pageInfo.setList(productVoList);
return ResponseVo.success(pageInfo);
}
<select id="selectByCategoryIdSet" resultMap="BaseResultMap">
select
<include refid="Base_Column_List" />
from mall_product
where status = 1
<if test="categoryIdSet.size() > 0">
and category_id in
<foreach collection="categoryIdSet" item="item" index="index" open="(" separator="," close=")">
#{
item}
</foreach>
</if>
</select>
1.2.4 dao
List<Product> selectByCategoryIdSet(@Param("categoryIdSet") Set<Integer> categoryIdSet);
1.2.5 mapper
<select id="selectByCategoryIdSet" resultMap="BaseResultMap">
select
<include refid="Base_Column_List" />
from mall_product
where status = 1
<if test="categoryIdSet.size() > 0">
and category_id in
<foreach collection="categoryIdSet" item="item" index="index" open="(" separator="," close=")">
#{
item}
</foreach>
</if>
</select>
Note: To
determine whether there is a value in the set, try not to use categoryIdSet! =null, but use categoryIdSet.size()> 0
<if test="categoryIdSet！=null">
Otherwise it will cause not all categories to be found
2 Product details
2.1 controller
@GetMapping("/products/{productId}")
public ResponseVo<ProductDetailVo> detail(@PathVariable Integer productId) {
return productService.detail(productId);
}
2.2 service
@Override
public ResponseVo<ProductDetailVo> detail(Integer productId) {
Product product = productMapper.selectByPrimaryKey(productId);
//只对确定性条件判断 下架，删除抛出异常
// 不用 ！product.getStatus().equals(ON_SALE.getCode() ，如果在加其他状态就不对啦
if (product.getStatus().equals(OFF_SALE.getCode())
|| product.getStatus().equals(DELETE.getCode())) {
return ResponseVo.error(PRODUCT_OFF_SALE_OR_DELETE);
}
ProductDetailVo productDetailVo = new ProductDetailVo();
BeanUtils.copyProperties(product, productDetailVo);
//敏感数据处理
productDetailVo.setStock(product.getStock() > 100 ? 100 : product.getStock());
return ResponseVo.success(productDetailVo);
}
In the project, define the entity class product. Input parameter packaged object ProductVo, and return result packaged object ProductDetailVo
note
BeanUtils.copyProperties(orderMasterDTO, orderMasterDO);
Function: Assign the attribute values in the orderMasterDTO object to orderMasterDO. The main purpose is to use the reflection mechanism to copy the attributes of the JavaBean.
benefit:
Without using the BeanUtils.copyProperties(orderMasterDTO, orderMasterDO) method, the traditional approach is: manually set the property value of orderMasterDTO to orderMasterDO
OrderMasterDO orderMasterDO = new OrderMasterDO();
orderMasterDO.setOrderId(orderMasterDTO.getOrderId());
orderMasterDO.setBuyerName(orderMasterDTO.getBuyerName());
orderMasterDO.setOrderStatus(orderMasterDTO.getOrderStatus());
orderMasterDO.setCreateTimestamp(orderMasterDTO.getCreateTimestamp());
orderMasterDO.setUpdateTimestamp(orderMasterDTO.getUpdateTimestamp());
Using the tool method of BeanUtils, only BeanUtils.copyProperties(orderMasterDTO, orderMasterDO) can ojbk, which is much simpler and more convenient.