【Java+MySql】好友關係數據庫設計及Java代碼實戰

　　業務需求：A、B兩個用戶的關注/取消關注接口

　　1、建表

 

 

由數據庫設計文檔和數據庫存放關係可知，

數據 用戶的userId 既可以在數據庫的user_id位置，也可以在數據庫的follower_id位置上。

　　2、該接口的實現思路如下

　　　　2.1、關注/取消關注 用戶的設計思路

　　　　參數：用戶A、用戶B、關注/取消關注flag

　　　　A和B的關係，假設A在數據庫的A位置

　　　　00 A關注B

　　　　01 B關注A

　　　　02 A、B相互關注

　　　　備註：A在數據庫的B位置時，如上關係爲01、00、02

　　　　2.2、實現思路如下：

　　　　0.去數據庫查詢A、B這兩個用戶有沒有關係(00/01/02)

　　　　1.點擊關注 --說明A和B的關係：1>沒有關係；2>B關注A

　　　　　　1-1.判斷A和B的關係

　　　　　　1-2.如果沒有關係，則添加一條數據

　　　　　　1-3.如果有關係，則將關係改爲相互關注(這個要結合實際，如果A已經關注了B，則A不能在關注B了，即進來

的肯定是B點擊了關注A)

　　　　2.3、點擊取消關注 --說明A和B的關係：

　　　　　　1>A關注B；2>A、B相互關注

　　　　2.4、判斷A和B的關係

　　　　　　2.4.1.如果是關注(結合實際，只有相互關注和關注兩種關係)，則取消關注，即刪除這條數據

　　　　　　2.4.2.如果是相互關注，則需要判斷A和B的位置

　　　　　　2.4.3 如果A在數據庫的A位置，則修改A和B的關係爲被關注--即關係爲01

　　　　　　2.4.4 如果A在數據庫的B位置，則修改A和B的關係爲被關注--即關係爲00

　　3、Java代碼實現

    /**
     * 添加用戶關注(關注、取消關注)
     * @param json
     * @return
     */
    @PostMapping("/addUserRelationShip")
    public Map<String,Object> addUserRelationShip(@RequestBody String json) {
        Map<String, Object> resultMap = new HashMap<>();
        UserRelationShip relationShip = JSON.parseObject(json, UserRelationShip.class);
        relationShip.setRelationId(UUID.randomUUID().toString().replace("-", ""));
        System.out.println(relationShip);

        JSONObject jsonObject = JSONObject.parseObject(json);
        Integer status = jsonObject.getInteger("status");
        String userId = jsonObject.getString("userId");
        String followerId = jsonObject.getString("followerId");

        //獲取A和B的關係
        List<UserRelationShip> userRelationShips = relationShipService.checkRelation(userId,followerId);
        if (userRelationShips.size() > 0 ) { //已經有關係了
            System.out.println("有關係了");
            UserRelationShip userRelationShip = userRelationShips.get(0);
            System.out.println(userRelationShip.getRelation());
            String relation = userRelationShip.getRelation();
            String relationUserId = userRelationShip.getUserId();
            String relationFollowerId = userRelationShip.getFollowerId();
            String position = "";
            if (userId.equals(relationUserId)) {
                position = "left";
            } else if (userId.equals(relationFollowerId)) {
                position = "right";
            }
            if (status == 1) { //執行關注操作
                if (position.equals("left")) {
                    if (relation.equals("00") || relation.equals("02")) { //自己在左邊：00:主動關注過對方，02：兩人互關着呢，不能再執行關注操作了
                        resultMap.put("message", "關注失敗，不能重複關注");
                        resultMap.put("state", JsonResult.failing);
                    } else {//對方在關注你，但是你沒有關注對方，所有執行操作，更改狀態爲02，變成互關的狀態
                        int updateCount = relationShipService.updateRelationStatus(userId,followerId,"02");
                        if (updateCount > 0) {
                            resultMap.put("message", "關注成功");
                            resultMap.put("state", JsonResult.SUCCESS);
                        } else {
                            resultMap.put("message", "關注失敗");
                            resultMap.put("state", JsonResult.failing);
                        }
                    }
                } else { //說明自己在右邊，關注是自己被對方主動關注過，
                    if (relation.equals("01") || relation.equals("02")) { //自己在右邊：01：自己關注別人了，02：兩人互關呢，不能再執行關注操作了
                        resultMap.put("message", "關注失敗，不能重複關注");
                        resultMap.put("state", JsonResult.failing);
                    } else { //00:對方在關注你，但是你沒有關注對方，所有執行操作，更改狀態爲02，變成互關的狀態
                        int updateCount = relationShipService.updateRelationStatus(userId,followerId,"02");
                        if (updateCount > 0) {
                            resultMap.put("message", "關注成功");
                            resultMap.put("state", JsonResult.SUCCESS);
                        } else {
                            resultMap.put("message", "關注失敗");
                            resultMap.put("state", JsonResult.failing);
                        }
                    }
                }
            } else {//執行取關操作
                if (position.equals("left")) {
                    if (relation.equals("00")) { //此時只有自己關注了對方，但是對方，卻沒有關注自己，所以執行取消操作的話，直接刪除就行了
                        int deleteCount = relationShipService.deleteUserRelationShip(userId,followerId);
                        if (deleteCount > 0) {
                            resultMap.put("message", "取消關注成功");
                            resultMap.put("state", JsonResult.SUCCESS);
                        } else {
                            resultMap.put("message", "取消關注失敗");
                            resultMap.put("state", JsonResult.failing);
                        }
                    } else if (relation.equals("02")) { //兩人互關呢，自己執行取關操作，要更改狀態爲01
                        int updateCount = relationShipService.updateRelationStatus(userId,followerId,"01");
                        if (updateCount > 0) {
                            resultMap.put("message", "取消關注成功");
                            resultMap.put("state", JsonResult.SUCCESS);
                        } else {
                            resultMap.put("message", "取消關注失敗");
                            resultMap.put("state", JsonResult.failing);
                        }
                    } else { //01時候，對方在關注者自己，就沒關注別人，取關個毛線啊
                        resultMap.put("message", "取消關注失敗");
                        resultMap.put("state", JsonResult.failing);
                    }
                } else { //說明自己在右邊，關注是自己被對方主動關注過，
                    if (relation.equals("01")) { //自己關注了對方，但是對方卻沒有關注自己，直接刪除就行了
                        int deleteCount = relationShipService.deleteUserRelationShip(userId,followerId);
                        if (deleteCount > 0) {
                            resultMap.put("message", "取消關注成功");
                            resultMap.put("state", JsonResult.SUCCESS);
                        } else {
                            resultMap.put("message", "取消關注失敗");
                            resultMap.put("state", JsonResult.failing);
                        }
                    } else if (relation.equals("02")) {
                        int updateCount = relationShipService.updateRelationStatus(userId,followerId,"00");
                        if (updateCount > 0) {
                            resultMap.put("message", "取消關注成功");
                            resultMap.put("state", JsonResult.SUCCESS);
                        } else {
                            resultMap.put("message", "取消關注失敗");
                            resultMap.put("state", JsonResult.failing);
                        }
                    } else { //你都沒關注別人，取關個毛線啊
                        resultMap.put("message", "取消關注失敗");
                        resultMap.put("state", JsonResult.failing);
                    }
                }
            }
        } else { //沒有關係
            System.out.println("沒有關係");
            relationShip.setRelation("00"); //既然沒有關係，就新增一條，記錄狀態標記爲00
            int addCount = relationShipService.addUserRelationShip(relationShip);
            if (addCount > 0) {
                System.out.println("新增關係成功");
                resultMap.put("message", "新增關注成功");
                resultMap.put("state", JsonResult.SUCCESS);
            } else {
                resultMap.put("message", "新增關注失敗");
                resultMap.put("state", JsonResult.failing);
            }
        }

        return  resultMap;
    }

　　備註：上述的sql語句：addUserRelationShip / deleteUserRelationShip / updateRelationStatus

    <!-- 檢查好友關係 -->
    <select id="checkRelation" resultMap="BasePlusResultMap">
        select * from follower where (user_id = #{userId} and follower_id = #{followerId}) or (user_id = #{followerId} and follower_id = #{userId})
    </select>

    <!-- 關注某人 -->
    <insert id="addUserRelationShip" >
        insert into follower(relation_id,user_id,follower_id,status,relation) values (#{relationId},#{userId},#{followerId},#{status},#{relation})
    </insert>

    <!-- 取消關注某人 -->
    <delete id="deleteUserRelationShip">
        delete from follower where user_id=#{userId} and follower_id = #{followerId}
    </delete>

    <!-- 更新還有關係狀態 -->
    <update id="updateRelationStatus">
        update follower set relation = #{relation} where (user_id = #{userId} and follower_id = #{followerId}) or (user_id = #{followerId} and follower_id = #{userId})
    </update>

　　封裝檢查好友關係的邏輯代碼，可以貼過去直接用的

    public static int checkRelationStatus(String userId,String targetId,List<Fans> userRelationShips) {

        int relationStatus = 0;
        for (int index = 0;index < userRelationShips.size();index++) {

            Fans userRelationShip = userRelationShips.get(index);
            String relationShipUserId = userRelationShip.getUserId();
            String relationShipFollowerId = userRelationShip.getFollowerId();
            String relation = userRelationShip.getRelation();

            if (relationShipUserId.equals(userId) && relationShipFollowerId.equals(targetId) || (relationShipUserId.equals(targetId) && relationShipFollowerId.equals(userId))) {
                String position = "";
                if (userId.equals(relationShipUserId)) {
                    position = "left";
                } else if (userId.equals(relationShipFollowerId)) {
                    position = "right";
                }
                if (position.equals("left")) {
                    if (relation.equals("00") || relation.equals("02")) { //自己在左邊：00:主動關注過對方，02：兩人互關着呢，不能再執行關注操作了
                        relationStatus = 1;
                    }
                } else { //說明自己在右邊，關注是自己被對方主動關注過，
                    if (relation.equals("01") || relation.equals("02")) { //自己在右邊：01：自己關注別人了，02：兩人互關呢，不能再執行關注操作了
                        relationStatus = 1;
                    }
                }
                break;
            }

        }

        return  relationStatus;
    }

　　4、獲取我的關注列表

    /* *//**
     * 獲取我的關注列表
     * @param userId
     * @param page
     * @param pageSize
     * @return
     */

    @GetMapping("/selectUserAttention")
    public Map<String,Object> selectUserAttention(String userId,int page,int pageSize){

        Map<String,Object> resultMap = new HashMap<>();
        List<RelationShipUser> relationUsers = new ArrayList<>();
        Map<String,Object> paramMap = new HashMap<>();
        paramMap.put("userId",userId);
        paramMap.put("followerId",userId);

        int pageCount = (page)* pageSize;
        paramMap.put("page", pageCount);
        paramMap.put("size",pageSize);
        List<Fans> userRelationShips = fansUserService.selectUserAttention(paramMap);
        if(userRelationShips.size() > 0) {
            List<String> userIds = new ArrayList<>();
            for (int index = 0;index < userRelationShips.size();index++) {
                Fans userRelationShip = userRelationShips.get(index);
                String relationShipUserId = userRelationShip.getUserId();
                String relationShipFollowerId = userRelationShip.getFollowerId();

                if (relationShipFollowerId.equals(userId)) {
                    userIds.add(relationShipUserId);
                } else {
                    userIds.add(relationShipFollowerId);
                }
            }

            System.out.println(userIds);
            //獲取用戶
            List<UserClone> users = relationShipService.queryUserWithIds(userIds);
            if (users.size() > 0) {
                for (int index = 0;index < users.size(); index++) {
                    RelationShipUser relationShipUser = new RelationShipUser();
                    relationShipUser.setUser(users.get(index));
                    relationUsers.add(relationShipUser);
                }
            }
            for (int idx = 0;idx < relationUsers.size();idx++) {
                RelationShipUser relationShipUser = relationUsers.get(idx);
                String targetId = relationShipUser.getUser().getUserId();
                int relationStatus = checkRelationStatus(userId,targetId,userRelationShips);
                relationShipUser.setStatus(relationStatus);
                relationUsers.set(idx,relationShipUser);
            }
            resultMap.put("data",relationUsers);
            resultMap.put("message", "查詢關注人成功");
            resultMap.put("state", JsonResult.SUCCESS);

        }else if(userRelationShips.size() == 0){
            resultMap.put("data",relationUsers);
            resultMap.put("message", "你還沒關注任何人");
            resultMap.put("state", JsonResult.SUCCESS);
        }else {
            resultMap.put("message", "查詢關注人失敗");
            resultMap.put("state", JsonResult.failing);
        }

        return resultMap;
    }

　　以上代碼所用的Sql語句：selectUserAttention

    <!--我的關注-->
    <select id="selectUserAttention" parameterType="Map" resultMap="BasePlusResultMap">
        select * from follower where (follower.user_id = #{userId} and follower.relation in ('00','02')) or
        (follower.follower_id = #{followerId} and follower.relation in ('01','02'))
         LIMIT #{page}, #{size}
    </select>

　　5、獲取我的粉絲

    /**
     * 獲取我的粉絲列表
     * @param userId
     * @param page
     * @param pageSize
     * @return
     */
    @GetMapping("/selectUserVermicelli")
    public Map<String,Object> selectUserVermicelli(String userId,int page,int pageSize){

        Map<String,Object> resultMap = new HashMap<>();
        List<RelationShipUser> relationUsers = new ArrayList<>();
        Map<String,Object> paramMap = new HashMap<>();
        paramMap.put("userId",userId);
        paramMap.put("followerId",userId);

        int pageCount = (page)* pageSize;
        paramMap.put("page", pageCount);
        paramMap.put("size",pageSize);
        List<Fans> userRelationShips = fansUserService.selectUserVermicelli(paramMap);
        if(userRelationShips.size() > 0){
            List<String> userIds = new ArrayList<>();

            for (int index = 0;index < userRelationShips.size();index++) {
                Fans userRelationShip = userRelationShips.get(index);

                String relationShipUserId = userRelationShip.getUserId();

                String relationShipFollowerId = userRelationShip.getFollowerId();

                if (relationShipFollowerId.equals(userId)) {
                    userIds.add(relationShipUserId);
                } else {
                    userIds.add(relationShipFollowerId);
                }
            }

            System.out.println(userIds);
            //獲取用戶
            List<UserClone> users = relationShipService.queryUserWithIds(userIds);
            if (users.size() > 0) {
                for (int index = 0;index < users.size(); index++) {
                    RelationShipUser relationShipUser = new RelationShipUser();
                    relationShipUser.setUser(users.get(index));
                    relationUsers.add(relationShipUser);
                }
            }
            for (int idx = 0;idx < relationUsers.size();idx++) {
                RelationShipUser relationShipUser = relationUsers.get(idx);
                String targetId = relationShipUser.getUser().getUserId();
                int relationStatus = checkRelationStatus(userId,targetId,userRelationShips);
                relationShipUser.setStatus(relationStatus);
                relationUsers.set(idx,relationShipUser);
            }

            resultMap.put("data",relationUsers);
            resultMap.put("message", "查詢成功");
            resultMap.put("state", JsonResult.SUCCESS);

        }else if(userRelationShips.size() == 0){
            resultMap.put("data",relationUsers);
            resultMap.put("message", "");
            resultMap.put("state", JsonResult.SUCCESS);
        }else {
            resultMap.put("message", "查詢失敗");
            resultMap.put("state", JsonResult.failing);
        }

        return resultMap;
    }

　　以上代碼所用到的Sql：selectUserVermicelli

   <!-- &lt;!&ndash;我的粉絲-->
    <select id="selectUserVermicelli" resultMap="BasePlusResultMap" parameterType="Map">

        select u2.nickname, u2.phone,u2.avatar,follower.follower_id  ,follower.relation_id,u2.user_id,follower.relation,u2.description,follower.user_id
            from follower
                inner join dnx_app_user u1 on follower.follower_id = u1.user_id

                inner join dnx_app_user u2 on follower.user_id = u2.user_id

                                where (follower.user_id = #{userId} and follower.relation in ('01','02')) or
        (follower.follower_id = #{followerId} and follower.relation in ('00','02'))
         LIMIT #{page}, #{size}
    </select>