学成在线-第14天-讲义-媒资管理 五

3.3 保存视频信息 
3.3.1 需求分析 
用户进入课程计划页面，选择视频，将课程计划与视频信息保存在课程管理数据库中。 
用户操作流程： 
1、进入课程计划，点击”选择视频“，打开我的媒资查询页面 
2、为课程计划选择对应的视频，选择“选择” 
3、前端请求课程管理服务保存课程计划与视频信息。 
3.3.2 数据模型 
在课程管理数据库创建表 teachplan_media 存储课程计划与媒资关联信息，如下：
 
创建teachplanMedia 模型类：、 

@Data
@ToString
@Entity
@Table(name="teachplan_media")
@GenericGenerator(name = "jpa‐assigned", strategy = "assigned")
public class TeachplanMedia implements Serializable {
private static final long serialVersionUID = ‐916357110051689485L;
@Id
@GeneratedValue(generator = "jpa‐assigned")
@Column(name="teachplan_id")
private String teachplanId;
@Column(name="media_id")
private String mediaId;
@Column(name="media_fileoriginalname")
private String mediaFileOriginalName;
@Column(name="media_url")
private String mediaUrl;
@Column(name="courseid")
private String courseId;
}

3.3.3 API接口 
此接口作为前端请求课程管理服务保存课程计划与视频信息的接口： 
在课程管理服务增加接口：

@ApiOperation("保存媒资信息")
public ResponseResult savemedia(TeachplanMedia teachplanMedia);

3.3.4 服务端开发 
3.3.3.1 DAO
创建TeachplanMediaRepository用于对TeachplanMedia的操作。

public interface TeachplanMediaRepository extends JpaRepository<TeachplanMedia, String> {
}

3.3.3.2 Service

//保存媒资信息
public ResponseResult savemedia(TeachplanMedia teachplanMedia) {
if(teachplanMedia == null){
ExceptionCast.cast(CommonCode.INVALIDPARAM);
}
//课程计划
String teachplanId = teachplanMedia.getTeachplanId();
//查询课程计划
Optional<Teachplan> optional = teachplanRepository.findById(teachplanId);
if(!optional.isPresent()){
ExceptionCast.cast(CourseCode.COURSE_MEDIA_TEACHPLAN_ISNULL);
}
Teachplan teachplan = optional.get();
//只允许为叶子结点课程计划选择视频
String grade = teachplan.getGrade();
if(StringUtils.isEmpty(grade) || !grade.equals("3")){
ExceptionCast.cast(CourseCode.COURSE_MEDIA_TEACHPLAN_GRADEERROR);
}
TeachplanMedia one = null;
Optional<TeachplanMedia> teachplanMediaOptional =
teachplanMediaRepository.findById(teachplanId);
if(!teachplanMediaOptional.isPresent()){
one = new TeachplanMedia();
}else{
one = teachplanMediaOptional.get();
}
//保存媒资信息与课程计划信息
one.setTeachplanId(teachplanId);
one.setCourseId(teachplanMedia.getCourseId());
one.setMediaFileOriginalName(teachplanMedia.getMediaFileOriginalName());
one.setMediaId(teachplanMedia.getMediaId());
one.setMediaUrl(teachplanMedia.getMediaUrl());
teachplanMediaRepository.save(one);
return new ResponseResult(CommonCode.SUCCESS);
}

3.3.3.3 Controller

@Override
@PostMapping("/savemedia")
public ResponseResult savemedia(@RequestBody TeachplanMedia teachplanMedia) {
return courseService.savemedia(teachplanMedia);
}

3.3.4 前端开发 
3.3.4.1 API方法 
定义api方法，调用课程管理服务保存媒资信息接口

/*保存媒资信息*/
export const savemedia = teachplanMedia => {
return http.requestPost(apiUrl+'/course/savemedia',teachplanMedia);
}

3.3.4.2 API调用 
在课程视频方法中调用api：

choosemedia(mediaId,fileOriginalName,mediaUrl){
this.mediaFormVisible = false;
//保存课程计划与视频对应关系
let teachplanMedia = {};
teachplanMedia.teachplanId = this.activeTeachplanId;
teachplanMedia.mediaId = mediaId;
teachplanMedia.mediaFileOriginalName = fileOriginalName;
teachplanMedia.mediaUrl = mediaUrl;
teachplanMedia.courseId = this.courseid;
//保存媒资信息到课程数据库
courseApi.savemedia(teachplanMedia).then(res=>{
if(res.success){
this.$message.success("选择视频成功")
}else{
this.$message.error(res.message)
}
})
},

3.3.4测试 
1、向叶子结点课程计划保存媒资信息 
操作结果：保存成功 
2、向非叶子结点课程计划保存媒资信息 
操作结果：保存失败