【学习日记】（SpringBoot-part 4）新闻管理系统—添加和修改新闻功能

添加新闻功能和修改功能的实现机制是差不多的，因此放到一起实现

效果展示

实现过程

1. 添加实体类且声明与其他实体关系

   在po文件下添加News实体信息如下，并在实体信息中声明和其他实体的关系
   实体关系：
   News to Type : n:1
   News to User : n:1
   News to Tags : n:n 因为News和Tags的实体关系为多对多，所以需要指定级联，生成一个News-Tag关系表

@Entity
@Table(name = "t_news")
public class News {
   

    @Id //主键标识
    @GeneratedValue(strategy = GenerationType.IDENTITY)  //自增
    private Long id;
    private String title;

    @Basic(fetch = FetchType.LAZY)        //懒加载  需要用到的时候再加载
    @Lob          //存储量较大的内容用到@lob
    private String content;
    private  String firstPicture;
    private String flag;
    private String views;
    private boolean appreciation;
    private boolean shareStatement;
    private boolean commentabled;
    private boolean published;
    private boolean recommend;
    @Temporal(TemporalType.TIMESTAMP) //指定时间戳
    private Date createTime;
    @Temporal(TemporalType.TIMESTAMP) //指定时间戳
    private Date updateTime;

    @ManyToOne
    private Type type;
    @ManyToOne
    private User user;
    //还要加标签tag
    @ManyToMany(cascade = CascadeType.PERSIST)   //指定级联
    private List<Tag> tags = new ArrayList<>();

    @Transient  //表示不会在数据库中生成这个字段  只存在于本实体中
    private String tagIds;

    private String description;
    public News() {
   
    }

    public Long getId() {
   
        return id;
    }

    public void setId(Long id) {
   
        this.id = id;
    }

    public String getTitle() {
   
        return title;
    }

    public void setTitle(String title) {
   
        this.title = title;
    }



    public String getContent() {
   
        return content;
    }

    public void setContent(String content) {
   
        this.content = content;
    }

    public String getFirstPicture() {
   
        return firstPicture;
    }

    public void setFirstPicture(String firstPicture) {
   
        this.firstPicture = firstPicture;
    }

    public String getFlag() {
   
        return flag;
    }

    public void setFlag(String flag) {
   
        this.flag = flag;
    }

    public String getViews() {
   
        return views;
    }

    public void setViews(String views) {
   
        this.views = views;
    }

    public boolean isAppreciation() {
   
        return appreciation;
    }

    public void setAppreciation(boolean appreciation) {
   
        this.appreciation = appreciation;
    }

    public boolean isShareStatement() {
   
        return shareStatement;
    }

    public void setShareStatement(boolean shareStatement) {
   
        this.shareStatement = shareStatement;
    }

    public boolean isCommentabled() {
   
        return commentabled;
    }

    public void setCommentabled(boolean commentabled) {
   
        this.commentabled = commentabled;
    }

    public boolean isPublished() {
   
        return published;
    }

    public void setPublished(boolean published) {
   
        this.published = published;
    }

    public boolean isRecommend() {
   
        return recommend;
    }

    public void setRecommend(boolean recommend) {
   
        this.recommend = recommend;
    }

    public Date getCreateTime() {
   
        return createTime;
    }

    public void setCreateTime(Date createTime) {
   
        this.createTime = createTime;
    }

    public Date getUpdateTime() {
   
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
   
        this.updateTime = updateTime;
    }

    public Type getType() {
   
        return