我已成功地在数据库中插入了一个图像文件，现在我想更改或更新插入的图像，请帮助我。
输出如下：

Could not set field value [com.mysql.cj.jdbc.Blob@2ab0fa13] 
   value by reflection : [class com.operation.Model.Users.image] setter of com.operation.Model.Users.image; 
nested exception is org.hibernate.PropertyAccessException: Could not set field value [com.mysql.cj.jdbc.Blob@2ab0fa13] 
   value by reflection : [class com.operation.Model.Users.image] setter of com.operation.Model.Users.image

控制器类

@RequestMapping("/UpdateData")
@ResponseBody
public String Updatedata(@RequestParam("id")int id,@RequestParam("username")String username,@RequestParam("file")MultipartFile file) {
    Users myUpdateData = service.getdataByid(id);
    myUpdateData.setUsername(username);
    myUpdateData.setImage(file);
    service.Updatedata(myUpdateData);
    return "success";
    
}

服务类

//Update data
public Users Updatedata(Users mod) {
    Users existdata = repo.findByid(mod.getId());
    existdata.setUsername(mod.getUsername());;
    existdata.setImage(mod.getImage());
    return repo.save(existdata);
    
}

存储库

public interface UsersRepo extends JpaRepository<Users, Integer>{

    
    Users findByid(int id);
}

用户类

@Entity
public class Users {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String username;
    
    @Lob
    @Column(columnDefinition = "MEDIUMBLOB")
    private String image;
    
    
    public String getImage() {
        return image;
    }
    public void setImage(String image) {
        this.image = image;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
            
}