一、新增分类 在开发代码之前,需要梳理一下整个程序的执行过程:
1、页面(backend/page/category/list.html)发送ajax请求,将新增分类窗口输入的数据以json形式提交到服务端
2、服务端Controller接收页面提交的数据并调用Service将数据进行保存
3、Service调用Mapper操作数据库,保存数据
可以先将大概的框架写出,后面在完善
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 package com.itheima.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 lombok.Getter; import lombok.Setter; import java.io.Serializable; import java.time.LocalDateTime; /** * 分类 */ @Data public class Category implements Serializable { private static final long serialVersionUID = 1L; private Long id; //类型 1 菜品分类 2 套餐分类 private Integer type; //分类名称 private String name; //顺序 private Integer sort; //创建时间 @TableField(fill = FieldFill.INSERT) private LocalDateTime createTime; //更新时间 @TableField(fill = FieldFill.INSERT_UPDATE) private LocalDateTime updateTime; //创建人 @TableField(fill = FieldFill.INSERT) private Long createUser; //修改人 @TableField(fill = FieldFill.INSERT_UPDATE) private Long updateUser; }
1 2 3 4 5 6 7 8 9 10 11 package com.itheima.reggie.mapper; import com.baomidou.mybatisplus.core.mapper.BaseMapper; import com.itheima.reggie.entity.Category; import org.apache.ibatis.annotations.Mapper; @Mapper public interface CategoryMapper extends BaseMapper<Category> { }
1 2 3 4 5 6 7 8 package com.itheima.reggie.service; import com.baomidou.mybatisplus.extension.service.IService; import com.itheima.reggie.entity.Category; public interface CategoryService extends IService<Category> { }
1 2 3 4 5 6 7 8 9 10 11 12 package com.itheima.reggie.service.impl; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.itheima.reggie.entity.Category; import com.itheima.reggie.mapper.CategoryMapper; import com.itheima.reggie.service.CategoryService; import org.springframework.stereotype.Service; @Service public class CategoryServiceImpl extends ServiceImpl<CategoryMapper, Category> implements CategoryService { }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 package com.itheima.reggie.controller; import com.itheima.reggie.service.CategoryService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/category") public class CategoryController { @Autowired private CategoryService categoryService; }
可以看到新增菜品分类和新增套餐分类请求的服务端地址和提交的json数据结构相同,所以服务端只需要提供一个方法统一处理即可:
二、分类信息分页查询 1、需求分析 系统中的分类很多的时候,如果在一个页面中全部展示出来会显得比较乱,不便于查看,所以一般的系统中都会以分页的方式来展示列表数据。
2、代码开发 在开发代码之前,需要梳理一下整个程序的执行过程:
1、页面发送ajax请求,将分页查询参数(page.pageSize)提交到服务端
2、服务端Controller接收页面提交的数据并调用Service查询数据
3、Service调用Mapper操作数据库,查询分页数据
4、Controller将查询到的分页数据响应给页面
5、页面接收到分页数据并通过Elementul的Table组件展示到页面上
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 package com.itheima.reggie.controller; import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper; import com.baomidou.mybatisplus.extension.plugins.pagination.Page; import com.itheima.reggie.common.R; import com.itheima.reggie.entity.Category; import com.itheima.reggie.service.CategoryService; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; /** * 分类管理 */ @RestController @RequestMapping("/category") @Slf4j public class CategoryController { @Autowired private CategoryService categoryService; /** * 新增分类 * @param category * @return */ @PostMapping public R<String> save(@RequestBody Category category){ log.info("category:{}",category); categoryService.save(category); return R.success("新增分类成功"); } /** * 分页查询 * @param page * @param pageSize * @return */ @GetMapping("/page") public R<Page> page(int page,int pageSize){ //分页构造器 Page<Category> pageInfo = new Page<>(page,pageSize); //条件构造器 LambdaQueryWrapper<Category> queryWrapper = new LambdaQueryWrapper<>(); //添加排序条件,根据sort进行排序 queryWrapper.orderByAsc(Category::getSort); //分页查询 categoryService.page(pageInfo,queryWrapper); return R.success(pageInfo); } }
最后就可以显示出来了。
三、删除分类 1、需求分析 在分类管理列表页面,可以对某个分类进行删除操作。需要注意的是当分类关联了菜品或者套餐时,此分类不允许删除。
2、代码开发 在开发代码之前,需要梳理一下整个程序的执行过程:
1、页面发送ajax请求,将参数(id)提交到服务端
2、服务端Controller接收页面提交的数据并调用Service删除数据
3、Service调用Mapper操作数据库
1 2 3 4 5 6 7 8 9 10 11 12 13 /** * 根据id删除分类 * @param id * @return */ @DeleteMapping public R<String> delete(Long id) { log.info("删除分类,id为:{}",id); categoryService.removeById(id); return R.success("分类信息删除成功"); }
3、功能完善 前面我们已经实现了根据id删除分类的功能,但是并没有检查删除的分类是否关联了菜品或者套餐,所以我们需要进行功能完善。
要完善分类删除功能,需要先准备基础的类和接口:1、实体类Dish和Setmeal (从课程资料中复制即可)
2、Mapper接口DishMapper和SetmealMapper
3、Service接口DishService和SetmealService
4、Service实现类DishServicelmpl和SetmealServicelmpl
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 package com.itheima.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; //是否删除 private Integer isDeleted; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 package com.itheima.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; //是否删除 private Integer isDeleted; }
1 2 3 4 5 6 7 8 9 10 package com.itheima.reggie.mapper; import com.baomidou.mybatisplus.core.mapper.BaseMapper; import com.itheima.reggie.entity.Dish; import org.apache.ibatis.annotations.Mapper; @Mapper public interface DishMapper extends BaseMapper<Dish> { }
1 2 3 4 5 6 7 8 9 10 package com.itheima.reggie.mapper; import com.baomidou.mybatisplus.core.mapper.BaseMapper; import com.itheima.reggie.entity.Setmeal; import org.apache.ibatis.annotations.Mapper; @Mapper public interface SetmealMapper extends BaseMapper<Setmeal> { }
1 2 3 4 5 6 7 8 package com.itheima.reggie.service; import com.baomidou.mybatisplus.extension.service.IService; import com.itheima.reggie.entity.Dish; public interface DishService extends IService<Dish> { }
1 2 3 4 5 6 7 8 package com.itheima.reggie.service; import com.baomidou.mybatisplus.extension.service.IService; import com.itheima.reggie.entity.Setmeal; public interface SetmealService extends IService<Setmeal> { }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 package com.itheima.reggie.service.impl; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.itheima.reggie.entity.Dish; import com.itheima.reggie.mapper.DishMapper; import com.itheima.reggie.service.DishService; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Service; @Service @Slf4j public class DishServiceImpl extends ServiceImpl<DishMapper, Dish> implements DishService { }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 package com.itheima.reggie.service.impl; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.itheima.reggie.entity.Setmeal; import com.itheima.reggie.mapper.SetmealMapper; import com.itheima.reggie.service.SetmealService; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Service; @Service @Slf4j public class SetmealServiceImpl extends ServiceImpl<SetmealMapper, Setmeal> implements SetmealService { }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 package com.itheima.reggie.controller; import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper; import com.baomidou.mybatisplus.extension.plugins.pagination.Page; import com.itheima.reggie.common.R; import com.itheima.reggie.entity.Category; import com.itheima.reggie.service.CategoryService; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; /** * 分类管理 */ @RestController @RequestMapping("/category") @Slf4j public class CategoryController { @Autowired private CategoryService categoryService; /** * 新增分类 * @param category * @return */ @PostMapping public R<String> save(@RequestBody Category category){ log.info("category:{}",category); categoryService.save(category); return R.success("新增分类成功"); } /** * 分页查询 * @param page * @param pageSize * @return */ @GetMapping("/page") public R<Page> page(int page,int pageSize){ //分页构造器 Page<Category> pageInfo = new Page<>(page,pageSize); //条件构造器 LambdaQueryWrapper<Category> queryWrapper = new LambdaQueryWrapper<>(); //添加排序条件,根据sort进行排序 queryWrapper.orderByAsc(Category::getSort); //分页查询 categoryService.page(pageInfo,queryWrapper); return R.success(pageInfo); } /** * 根据id删除分类 * @param id * @return */ @DeleteMapping public R<String> delete(Long id) { log.info("删除分类,id为:{}",id); //categoryService.removeById(id); categoryService.remove(id); return R.success("分类信息删除成功"); } }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 package com.itheima.reggie.service.impl; import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.itheima.reggie.common.CustomException; import com.itheima.reggie.entity.Category; import com.itheima.reggie.entity.Dish; import com.itheima.reggie.entity.Setmeal; import com.itheima.reggie.mapper.CategoryMapper; import com.itheima.reggie.service.CategoryService; import com.itheima.reggie.service.DishService; import com.itheima.reggie.service.SetmealService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; @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 */ @Override 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) { //已经关联菜品,抛出一个业务异常 throw new CustomException("当前分类下关联了分类菜品,不能删除"); } //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<>(); int count2 = setmealService.count(setmealLambdaQueryWrapper); if (count2 > 0) { //已经关联套餐,抛出一个业务异常 throw new CustomException("当前分类下关联了套餐,不能删除"); } //正常删除分类 super.removeById(id); } }
1 2 3 4 5 6 7 8 9 10 11 12 package com.itheima.reggie.common; /** * 自定义业务异常 */ public class CustomException extends RuntimeException{ public CustomException(String message) { super(message); } }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 package com.itheima.reggie.common; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.ControllerAdvice; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.bind.annotation.RestController; import java.sql.SQLIntegrityConstraintViolationException; /** * 全局异常处理 */ @ControllerAdvice(annotations = {RestController.class, Controller.class}) @ResponseBody @Slf4j public class GlobalExceptionHandler { /** * 异常处理方法 * @return */ @ExceptionHandler(SQLIntegrityConstraintViolationException.class) public R<String> exceptionHandler(SQLIntegrityConstraintViolationException ex){ log.error(ex.getMessage()); if(ex.getMessage().contains("Duplicate entry")){ String[] split = ex.getMessage().split(" "); String msg = split[2] + "已存在"; return R.error(msg); } return R.error("未知错误"); } /** * 异常处理方法 * @return */ @ExceptionHandler(CustomException.class) public R<String> exceptionHandler(CustomException ex){ log.error(ex.getMessage()); return R.error(ex.getMessage()); } }
四、修改分类 1、需求分析 在分类管理列表页面点击修改按钮,弹出修改窗口,在修改窗口回显分类信息并进行修改,最后点击确定按钮完成修改操作
2、代码开发 1 2 3 4 5 6 7 8 9 10 11 12 13 14 /** * 根据id修改分类信息 * @param category * @return */ @PutMapping public R<String> update(@RequestBody Category category){ log.info("修改分类信息:{}",category); categoryService.updateById(category); return R.success("修改分类信息成功"); }