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：


[mw_shl_code=applescript,true]@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;    } 
[/mw_shl_code]

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：


[mw_shl_code=applescript,true]@ApiOperation("保存媒资信息") 
public ResponseResult savemedia(TeachplanMedia teachplanMedia);[/mw_shl_code]
3.3.4  服务端开发 3.3.3.1 DAO 
创建TeachplanMediaRepository用于对TeachplanMedia的操作。

[mw_shl_code=applescript,true]public interface TeachplanMediaRepository extends JpaRepository {  
}   
[/mw_shl_code]
3.3.3.2 Service 
[mw_shl_code=applescript,true]//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 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 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); 
  }[/mw_shl_code]
3.3.3.3 Controller 
[mw_shl_code=applescript,true]@Override
@PostMapping("/savemedia") public ResponseResult savemedia(@RequestBody TeachplanMedia teachplanMedia) {     return courseService.savemedia(teachplanMedia);
}[/mw_shl_code]