创新实训——获取帖子接口的实现

    每次请求获取帖子接口时，分页获取帖子，每次返回五个帖子。

   当请求的参数mid即帖子的id为-1时，返回最新的5个帖子，逆序返回；当请求的参数mid即帖子的id大于等于0时，返回mid~mid-4的五个帖子，逆序返回。

    返回的内容包括：帖子的内容、图片、评论、帖子创建时间、点赞数、该用户是否点赞。

关键代码：

                if (mid < 0) {
                    sql = "SELECT MAX(mid) AS maxid FROM moment";
                    statement = conn.prepareStatement(sql);
                    resultSet = statement.executeQuery();
                    if (resultSet.next()) {
                        mid = resultSet.getInt("maxid");
                    }
                }
                sql = "SELECT * FROM moment WHERE mid<=? AND mid>? ORDER BY mid DESC ";
                statement = conn.prepareStatement(sql);
                statement.setInt(1, mid);
                statement.setInt(2, mid - 5);
                resultSet = statement.executeQuery();
                while (resultSet.next()) {
                    String comments = resultSet.getString("comments");
                    String likes = resultSet.getString("likes");
                    momentBean.moments.add(new MomentBean()
                            .setComments(getCommentBack(comments, conn))
                            .setImgs(resultSet.getString("imgs"))
                            .setText(resultSet.getString("text"))
                            .setMomentId(resultSet.getInt("mid"))
                            .setTime(resultSet.getString("date"))
                            .setUserId(Integer.parseInt(resultSet.getString("uid")))
                            .setLikes(getLikesNum(likes))
                            .setHasLike(getHasLike(likes, uid)));
                }
                momentBean.status = BaseConsts.STATUS_SUCESSED;