关于保存接口的java代码(新增,修改)

controller:
/**
 * 保存接口(新增和删除)
 */
@PostMapping ("/saveCategory")
public Result saveCategory(@RequestBody BroadScopeSaveDTO dto) {

    broadScopeService.saveCategory(dto);
    return Result.success();
}

传参的dto:

@Data
public class BroadScopeSaveDTO {
    /**
     * 主键
     */

    private Long id;
    /**
     * 类目名称
     */

    private String categoryName;

    /**
     * 排序
     */

    private Long sort;
}
service:

Result saveCategory(BroadScopeSaveDTO dto);
impl:

  /**
     * 保存接口(新增或者删除)
     *
     * @param dto
     * @return
     */

    @Override
    @Transactional(rollbackFor = Exception.class)
    public Result saveCategory(BroadScopeSaveDTO dto) {

        //先判断传来的名字是否是重复的
        long l = broadScopeMapper.countByName(dto.getCategoryName());
        if (l>0){
            //如果重复就报错,该分类已存在
            throw new BusinessException(MessageConstant.CATEGORY_EXISTS);
        }
        //然后判断传来的id是否有值(有修改.无新增)
        if (ObjectUtil.isNull(dto.getId())){
            boolean b = broadScopeMapper.insertCategory(dto);
            if (ObjectUtil.isNull(b)){
                //插入失败,保存失败
                throw new BusinessException(MessageConstant.SAVE_FAILED);
            }
        }else {
            //修改,修改前要查找旧的名字
            String byName = broadScopeMapper.findByName(dto.getId());
            boolean b = broadScopeMapper.updateCategory(dto.getId(), dto.getCategoryName(), dto.getSort());
            if (ObjectUtil.isNull(b)){
                //修改失败
                throw new BusinessException(MessageConstant.UPDATE_FAILED);
            }
            //批量替换,旧名字变成新名字
            Boolean b1 = broadScopePromptMapper.updateByCategoryName(byName, dto.getCategoryName());
            if (ObjectUtil.isNull(b1)){
                //批量替换修改失败
                throw new BusinessException(MessageConstant.UPDATE_FAILED);
            }
        }
        return Result.success();
    }

BroadScopeMapper

mapper:

/**
 *  根据分类名字查询个数
 * @param categoryName
 * @return
 */
long countByName(String categoryName);

xml:

    select count(id) from broadscope_prompt_category  where  category_name=#{categoryName}

mapper:

/**
 * 新增分类
 * @param dto
 * @return
 */
boolean insertCategory(BroadScopeSaveDTO dto);

xml:

insert into broadscope_prompt_category (id,category_name,status) values (null,#{categoryName},1)

mapper:

/**
 *  根据id查询分类名称
 * @param id
 * @return
 */
String findByName(Long id);

xml:

    select category_name from broadscope_prompt_category
    where id =#{id}

mapper:

/**
 * 修改分类
 * @param id
 * @param categoryName
 * @param sort
 * @return
 */
boolean updateCategory(Long id, String categoryName, Long sort);

xml:

  update  broadscope_prompt_category
    
        
            category_name=#{categoryName},
        
        
            sort=#{sort}
        
    
    where id =#{id}

BroadScopePromptMapper

mapper:

/**
 * 批零替换名字
 * @param
 * @param categoryName
 * @return
 */

Boolean updateByCategoryName(String name, String categoryName);

xml:

  
      update  broadscope_prompt
      
     category =#{categoryName}
      
      where  category=#{name}
  

测试: