day82-商城业务-整合dev-tools渲染一级分类数据

1.之前新建的web文件夹（专门用于页面跳转）下添加首页方法

package com.atguigu.gulimall.product.web;

import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.List;

/**
 * @author rengang
 * @version 1.0
 * @date 2021/1/12 7:36
 */
@Controller
public class IndexController {

    @Autowired
    CategoryService categoryService;

    @RequestMapping({"/","/index"})
    public String index(Model model){

      List<CategoryEntity> category1s =  categoryService.findCatelog1s();

        model.addAttribute("category1s",category1s);

        return "index";
    }
}

2.查询一级分类

service层代码

    @Override
    public List<CategoryEntity> findCatelog1s() {
       return this.list(new QueryWrapper<CategoryEntity>().eq("parent_cid",0));
    }

3.首页中显示

index.html中修改

   <ul>
            <li th:each="category:${category1s}">
              <a href="#" class="header_main_left_a" ctg-data="${category.catId}"><b th:text="${category.name}">家用电器</b></a>
            </li>
          </ul>

可以看到首页上左侧正常显示一级分类

4.添加devtools依赖，这样以后就不用一改代码就重启了

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

就可以ctrl+F9或者在该文件上ctrl+shift+F9，来手动编译