瑞吉外卖（12） - 删除分类功能开发

需求分析

代码开发

前端测试

添加CategoryController.java方法

这里必须要用ids参数，不然无法捕获id，原因未知

    /**
     * 根据id删除分类
     * @param id
     * @return
     */
    @DeleteMapping
    public R<String> delete(Long ids){
    
    
        log.info("删除分类,id为：{}",ids);
        categoryService.removeById(ids);
        return R.success("分类信息删除成功");
    }

功能测试

正常

功能完善

模块搭建

实体类Dish.java

package com.taotao.reggie.entity;

import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.Data;
import java.io.Serializable;
import java.math.BigDecimal;
import java.time.LocalDateTime;

/**
 菜品
 */
@Data
public class Dish implements Serializable {
    
    

    private static final long serialVersionUID = 1L;

    private Long id;


    //菜品名称
    private String name;


    //菜品分类id
    private Long categoryId;


    //菜品价格
    private BigDecimal price;


    //商品码
    private String code;


    //图片
    private String image;


    //描述信息
    private String description;


    //0 停售 1 起售
    private Integer status;


    //顺序
    private Integer sort;


    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;


    @TableField(fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;


    @TableField(fill = FieldFill.INSERT)
    private Long createUser;


    @TableField(fill = FieldFill.INSERT_UPDATE)
    private Long updateUser;

}

DishMapper.java

package com.taotao.reggie.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.taotao.reggie.entity.Dish;
import org.apache.ibatis.annotations.Mapper;

/**
 * create by 刘鸿涛
 * 2022/6/8 8:16
 */
@SuppressWarnings({
    
    "all"})
@Mapper
public interface DishMapper extends BaseMapper<Dish> {
    
    
}

DisService.java

package com.taotao.reggie.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.taotao.reggie.entity.Dish;

/**
 * create by 刘鸿涛
 * 2022/6/8 8:18
 */
@SuppressWarnings({
    
    "all"})
public interface DishService extends IService<Dish> {
    
    
}

DishServiceImpl.java

package com.taotao.reggie.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.taotao.reggie.entity.Dish;
import com.taotao.reggie.mapper.DishMapper;
import com.taotao.reggie.service.DishService;
import lombok.extern.slf4j.Slf4j;

/**
 * create by 刘鸿涛
 * 2022/6/8 8:21
 */
@SuppressWarnings({
    
    "all"})
@Service
@Slf4j
public class DishServiceImpl extends ServiceImpl<DishMapper, Dish> implements DishService {
    
    
}

实体类Setmeal.java

package com.taotao.reggie.entity;

import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.Data;
import java.io.Serializable;
import java.math.BigDecimal;
import java.time.LocalDateTime;

/**
 * 套餐
 */
@Data
public class Setmeal implements Serializable {
    
    

    private static final long serialVersionUID = 1L;

    private Long id;


    //分类id
    private Long categoryId;


    //套餐名称
    private String name;


    //套餐价格
    private BigDecimal price;


    //状态 0:停用 1:启用
    private Integer status;


    //编码
    private String code;


    //描述信息
    private String description;


    //图片
    private String image;


    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;


    @TableField(fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;


    @TableField(fill = FieldFill.INSERT)
    private Long createUser;


    @TableField(fill = FieldFill.INSERT_UPDATE)
    private Long updateUser;

}

SetmealMapper.java

package com.taotao.reggie.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.taotao.reggie.entity.Setmeal;
import org.apache.ibatis.annotations.Mapper;

/**
 * create by 刘鸿涛
 * 2022/6/8 8:17
 */
@SuppressWarnings({
    
    "all"})
@Mapper
public interface SetmealMapper extends BaseMapper<Setmeal> {
    
    
}

SetmealService.java

package com.taotao.reggie.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.taotao.reggie.entity.Setmeal;

/**
 * create by 刘鸿涛
 * 2022/6/8 8:20
 */
@SuppressWarnings({
    
    "all"})
public interface SetmealService extends IService<Setmeal> {
    
    
}

SetmealServiceImpl.java

package com.taotao.reggie.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.taotao.reggie.entity.Setmeal;
import com.taotao.reggie.mapper.SetmealMapper;
import com.taotao.reggie.service.SetmealService;
import lombok.extern.slf4j.Slf4j;

/**
 * create by 刘鸿涛
 * 2022/6/8 8:23
 */
@SuppressWarnings({
    
    "all"})
@Slf4j
@Service
public class SetmealServiceImpl extends ServiceImpl<SetmealMapper, Setmeal> implements SetmealService {
    
    
}

功能实现

CategoryService.java添加方法

    void remove(Long id);

方法改造

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既然是改造mybatis框架方法，那么就需要在service层写业务

编写CategoryServiceImpl.java

package com.taotao.reggie.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.taotao.reggie.common.CustomException;
import com.taotao.reggie.entity.Category;
import com.taotao.reggie.entity.Dish;
import com.taotao.reggie.entity.Setmeal;
import com.taotao.reggie.mapper.CategoryMapper;
import com.taotao.reggie.service.CategoryService;
import com.taotao.reggie.service.DishService;
import com.taotao.reggie.service.SetmealService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * create by 刘鸿涛
 * 2022/6/7 7:12
 */
@SuppressWarnings({
    
    "all"})
@Service
public class CategoryServiceImpl extends ServiceImpl<CategoryMapper, Category> implements CategoryService {
    
    

    @Autowired
    private DishService dishService;

    @Autowired
    private SetmealService setmealService;
    /**
     * 根据id删除分类，删除之前需要进行判断
     * @param id
     */
    public void remove(Long id){
    
    
        LambdaQueryWrapper<Dish> dishLambdaQueryWrapper = new LambdaQueryWrapper<>();
        //添加查询条件，根据分类id进行查询
        dishLambdaQueryWrapper.eq(Dish::getCategoryId,id);
        int count1 = dishService.count(dishLambdaQueryWrapper);

        //查询当前分类是否关联了菜品，如果已经关联，抛出一个业务异常
        if(count1 > 0){
    
    
            throw new CustomException("当前分类下关联了菜品，不能删除");
            //已经关联菜品，抛出一个异常
        }

        //查询当前分类是否关联了套餐，如果已经关联，抛出一个业务异常
        LambdaQueryWrapper<Setmeal> setmealLambdaQueryWrapper = new LambdaQueryWrapper<>();
        //添加查询条件，根据分类id进行查询
        setmealLambdaQueryWrapper.eq(Setmeal::getCategoryId,id);
        int count2 = setmealService.count();
        if(count2 > 0){
    
    
            throw new CustomException("当前分类下关联了套餐，不能删除");
            //已经关联了套餐，抛出一个业务异常
        }

        //正常删除分类
        super.removeById(id);
    }
}

自定义业务异常CustomException.java

package com.taotao.reggie.common;

/**
 * create by 刘鸿涛
 * 2022/6/8 9:03
 */
@SuppressWarnings({
    
    "all"})
public class CustomException extends RuntimeException{
    
    
    public CustomException(String message){
    
    
        super(message);
    }
}

GlobalExceptionHandler.java添加方法

    /**
     * 异常处理
     * @param ex
     * @return
     */
    @ExceptionHandler(CustomException.class)
    public R<String> exceptionHandler(CustomException ex){
    
    
        log.error(ex.getMessage());
        return R.error(ex.getMessage());
    }

功能测试

有关联失败

无关联成功

添加测试分类