频道管理——增删改查

对频道进行增删改查，在admin网关中增加leadnews-media路由

package com.heima.wemedia.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.heima.model.common.dtos.PageResponseResult;
import com.heima.model.common.dtos.ResponseResult;
import com.heima.model.common.enums.AppHttpCodeEnum;
import com.heima.model.wemedia.dtos.ChannelDto;
import com.heima.model.wemedia.pojos.WmChannel;
import com.heima.model.wemedia.pojos.WmNews;
import com.heima.wemedia.mapper.WmChannelMapper;
import com.heima.wemedia.service.WmChannelService;
import com.heima.wemedia.service.WmNewsService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Date;
import java.util.List;

@Service
@Transactional
@Slf4j
public class WmChannelServiceImpl extends ServiceImpl<WmChannelMapper, WmChannel> implements WmChannelService {


    /**
     * 查询所有频道
     * @return
     */
    @Override
    public ResponseResult finddAll() {
        return ResponseResult.okResult(list());
    }

    /**
     * 保存频道
     *
     * @param adChannel
     * @return
     */
    @Override
    public ResponseResult insert(WmChannel adChannel) {
        //验证参数
        if(adChannel == null){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID);
        }
        //频道名称不能重复,根据名称查询是否存在
        WmChannel channel = getOne(Wrappers.<WmChannel>lambdaQuery().eq(WmChannel::getName, adChannel.getName()));
        //频道名称已存在
        if(channel != null){
            return ResponseResult.errorResult(AppHttpCodeEnum.DATA_EXIST, "频道已存在");
        }
        adChannel.setCreatedTime(new Date());
        save(adChannel);
        return ResponseResult.okResult(AppHttpCodeEnum.SUCCESS);
    }

    /**
     * 分页查询、条件查询
     *
     * @param dto
     * @return
     */
    @Override
    public ResponseResult findByNameAndPage(ChannelDto dto) {
        //检查参数
        if(dto == null){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID);
        }
        //检查分页
        dto.checkParam();

        //分页构造器
        Page<WmChannel> page = new Page<>(dto.getPage(), dto.getSize());

        //条件构造器
        LambdaQueryWrapper<WmChannel> queryWrapper = new LambdaQueryWrapper<>();
        //添加查询条件，模糊查询
        queryWrapper.like(dto.getName()!=null, WmChannel::getName, dto.getName());
        //添加排序时间，降序
        queryWrapper.orderByDesc(WmChannel::getCreatedTime);

        page = page(page, queryWrapper);

        //结果返回
        ResponseResult responseResult = new PageResponseResult(dto.getPage(), dto.getSize(), (int) page.getTotal());
        responseResult.setData(page.getRecords());
        return responseResult;

    }

    @Autowired
    private WmNewsService wmNewsService;

    /**
     * 修改频道
     *
     * @param wmChannel
     * @return
     */
    @Override
    public ResponseResult update(WmChannel wmChannel) {
        //检查参数
        if(wmChannel == null || wmChannel.getId() == null){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID);
        }
        //判断是否被引用
        int count = wmNewsService.count(Wrappers.<WmNews>lambdaQuery().eq(WmNews::getChannelId, wmChannel.getId()).eq(WmNews::getStatus, WmNews.Status.PUBLISHED.getCode()));
        if(count > 0){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID, "频道被引用无法删除");
        }
        updateById(wmChannel);
        return ResponseResult.okResult(AppHttpCodeEnum.SUCCESS);
    }

    /**
     * 删除频道
     *
     * @param id
     * @return
     */
    @Override
    public ResponseResult delete(Integer id) {
        //检查参数
        if(id == null){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID);
        }
        //查询频道
        WmChannel channel = getById(id);
        if(channel == null){
            return ResponseResult.errorResult(AppHttpCodeEnum.DATA_NOT_EXIST, "频道不存在");
        }
        //检查该频道是否被启用
        if(channel.getStatus()){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID, "频道有效，无法操作");
        }
        //检查该频道是否被引用
        int count = wmNewsService.count(Wrappers.<WmNews>lambdaQuery().eq(WmNews::getChannelId, id).eq(WmNews::getStatus, WmNews.Status.PUBLISHED.getCode()));
        if(count > 0){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID, "频道被引用，无法删除");
        }
        removeById(id);
        return ResponseResult.okResult(AppHttpCodeEnum.SUCCESS);
    }
}