1.3 分类实现 - 加载与渲染大分类

在 foodie-dev-service 模块下面的 com.imooc.service 包内创建 CategoryService 接口

package com.imooc.service;
import com.imooc.pojo.Category;
import java.util.List;
/**
 * Created by 92578 on 2020/8/22 16:17
 **/
public interface CategoryService {
    /**
     * 查询所有一级分类
     *
     * @return
     */
    public List<Category> queryAllRootLevelCat();
}

在 foodie-dev-service 模块下面的 com.imooc.service.impl 包内创建 CategoryServiceImpl 类

package com.imooc.service.impl;
import com.imooc.mapper.CategoryMapper;
import com.imooc.pojo.Category;
import com.imooc.service.CategoryService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import tk.mybatis.mapper.entity.Example;
import java.util.List;
/**
 * Created by 92578 on 2020/8/22 16:18
 **/
@Service
public class CategoryServiceImpl implements CategoryService {
    @Autowired
    private CategoryMapper categoryMapper;
    /**
     * 查询所有一级分类
     *
     * @return
     */
    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public List<Category> queryAllRootLevelCat() {
        Example example = new Example(Category.class);
        Example.Criteria criteria = example.createCriteria();
        criteria.andEqualTo("type", 1);
        List<Category> result = categoryMapper.selectByExample(example);
        return result;
    }
}

在 foodie-dev-api 模块下面的 IndexController 类新增 cats 方法

package com.imooc.controller;

import com.imooc.enums.YseOrNo;
import com.imooc.pojo.Carousel;
import com.imooc.pojo.Category;
import com.imooc.service.CarouselService;
import com.imooc.service.CategoryService;
import com.imooc.utils.IMOOCJSONResult;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * Created by 92578 on 2020/8/22 16:30
 **/
@Api(value = "首页", tags = {"首页展示的相关接口"})
@RestController
@RequestMapping("index")
public class IndexController {

    @Autowired
    private CarouselService carouselService;

    @Autowired
    private CategoryService categoryService;

    @ApiOperation(value = "获取首页轮播图列表", notes = "获取首页轮播图列表", httpMethod = "GET")
    @GetMapping("/carousel")
    public IMOOCJSONResult carousel() {
        List<Carousel> list = carouselService.queryAll(YseOrNo.YES.type);

        return IMOOCJSONResult.ok(list);
    }

    @ApiOperation(value = "获取商品分类(一级分类)", notes = "获取商品分类(一级分类)", httpMethod = "GET")
    @GetMapping("/cats")
    public IMOOCJSONResult cats() {
        List<Category> list = categoryService.queryAllRootLevelCat();

        return IMOOCJSONResult.ok(list);
    }
}

启动项目，打开浏览器，访问 http://localhost:8088/doc.html
找到获取商品分类（一级分类）接口，点击“调试”->“发送”，成功获取相应数据

访问 http://localhost:8080/foodie-shop/index.html