org.springframework.dao.InvalidDataAccessApiUsageException:[color=#FF6600] detached entity passed to persist[/color]: com.myproject.hrsystem.entity.Post; nested exception is org.hibernate.PersistentObjectException: detached entity passed to persist: com.myproject.hrsystem.entity.Post

Department类：
@ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(name = "TBL_DeptPost", joinColumns = { @JoinColumn(name = "dept_ID") }, inverseJoinColumns = { @JoinColumn(name = "post_Id") })
    public Set<Post> getPosts() {
        return posts;
    }
Post类：
@ManyToMany(mappedBy = "posts",cascade = CascadeType.ALL)
    public Set<Department> getDepartments() {
        return departments;
    }

Set<Post> posts = new HashSet<Post>();
            Company cmp = new Company();// 设置公司信息
            cmp.setCmpId(1);
            String[] postIds = request.getParameterValues("select2");// 获取部门ID
            // 如果职位ID数组不为空，则循环遍历职位数组，取出职位ID
            if (StringUtil.isNullOrEmpty(postIds)) {
                for (String s : postIds) {
                    Integer pid = Integer.parseInt(s); // 获取职位ID
                    Post tempPost = new Post();
                    System.out.println("职位ID:-----"+pid);
                    tempPost.setPostId(pid);
                    posts.add(tempPost); // 将职位信息添加到集合中
                }
            }
            dept.setPosts(posts);// 所属职位
            dept.setCmp(cmp);// 所属公司
            dept.setEmpId(empId);// 部门经理
            dept.setAddId(empId);// 建立人
            dept.setAddTime(new Date());// 建立时间
            dept.setDelSt(0);// 删除标识