hibernate 多对多双向关联

@ManyToMany(fetch = FetchType.LAZY, cascade = {CascadeType.ALL})
	@Cascade( { org.hibernate.annotations.CascadeType.ALL } )
	@JoinTable(name="a_c",
    joinColumns={@JoinColumn(name="article_id")},
    inverseJoinColumns={@JoinColumn(name="category_id")}
	)
	Set<Category> categories = new HashSet<Category>();   //目录
           

@ManyToMany(fetch = FetchType.LAZY, cascade = {CascadeType.ALL})
	@Cascade( { org.hibernate.annotations.CascadeType.ALL } )
	@JoinTable(name="a_c",
	        joinColumns={@JoinColumn(name="category_id")},
	        inverseJoinColumns={@JoinColumn(name="article_id")}
			)
	Set<Article> articles=new HashSet<Article>();   //目录中的文章
           

此时，hibernate会生成中间表  a_c .