11-5 增加定时任务，定时从ebook收集数据生成ebook_snapshot数据

src/main/java/io/github/yubincloud/fairywiki/job/EbookSnapshotJob.java

+package io.github.yubincloud.fairywiki.job;
+
+import io.github.yubincloud.fairywiki.service.EbookSnapshotService;
+import io.github.yubincloud.fairywiki.utils.SnowFlake;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+
+import javax.annotation.Resource;
+
+@Component
+public class EbookSnapshotJob {
+
+    private static final Logger LOG = LoggerFactory.getLogger(EbookSnapshotJob.class);
+
+    @Resource
+    private EbookSnapshotService ebookSnapshotService;
+
+    @Resource
+    private SnowFlake snowFlake;
+
+    /**
+     * 自定义cron表达式跑批
+     * 只有等上一次执行完成，下一次才会在下一个时间点执行，错过就错过
+     */
+    @Scheduled(cron = "0/5 * * * * ?")
+    public void doSnapshot() {
+        // 增加日志流水号
+        MDC.put("LOG_ID", String.valueOf(snowFlake.nextId()));
+        LOG.info("生成今日电子书快照开始");
+        long start = System.currentTimeMillis();
+        ebookSnapshotService.genSnapshots();
+        LOG.info("生成今日电子书快照结束，耗时：{}毫秒", System.currentTimeMillis() - start);
+    }
+
+}

src/main/java/io/github/yubincloud/fairywiki/mapper/EbookSnapshotMapperCustom.java

+package io.github.yubincloud.fairywiki.mapper;
+
+public interface EbookSnapshotMapperCustom {
+    void genSnapshot();
+}

src/main/java/io/github/yubincloud/fairywiki/service/EbookSnapshotService.java

 package io.github.yubincloud.fairywiki.service;
 
-import io.github.yubincloud.fairywiki.mapper.EbookSnapshotMapper;
+import io.github.yubincloud.fairywiki.mapper.EbookSnapshotMapperCustom;
 import org.springframework.stereotype.Service;
 
 import javax.annotation.Resource;
@@ -9,5 +9,9 @@ import javax.annotation.Resource;
 public class EbookSnapshotService {
 
     @Resource
-    private EbookSnapshotMapper ebookSnapshotMapper;
+    private EbookSnapshotMapperCustom ebookSnapshotMapperCustom;
+
+    public void genSnapshots() {
+        ebookSnapshotMapperCustom.genSnapshot();
+    }
 }

src/main/resources/mapper/EbookSnapshotMapperCustom.xml

+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
+<mapper namespace="io.github.yubincloud.fairywiki.mapper.EbookSnapshotMapperCustom" >
+
+    <!--
+    # 方案一（ID不连续）：
+    #   删除今天的数据
+    #   为所有的电子书生成一条今天的记录
+    #   更新总阅读数、总点赞数
+    #   更新今日阅读数、今日点赞数
+    # 方案二（ID连续）：
+    #   为所有的电子书生成一条今天的记录，如果还没有
+    #   更新总阅读数、总点赞数
+    #   更新今日阅读数、今日点赞数
+    -->
+    <update id="genSnapshot">
+        INSERT INTO ebook_snapshot(ebook_id, `date`, view_count, vote_count, view_increase, vote_increase)
+        SELECT t1.id, curdate(), 0, 0, 0, 0
+        FROM ebook t1
+        WHERE NOT EXISTS(SELECT 1
+                         FROM ebook_snapshot t2
+                         WHERE t1.id = t2.ebook_id
+                           AND t2.`date` = curdate());
+
+        UPDATE ebook_snapshot t1, ebook t2
+        SET t1.view_count = t2.view_count,
+            t1.vote_count = t2.vote_count
+        WHERE t1.`date` = curdate()
+          AND t1.ebook_id = t2.id;
+
+        UPDATE ebook_snapshot t1 LEFT JOIN (SELECT ebook_id, view_count, vote_count
+                                            FROM ebook_snapshot
+                                            WHERE `date` = date_sub(curdate(), INTERVAL 1 DAY)) t2
+            ON t1.ebook_id = t2.ebook_id
+        SET t1.view_increase = (t1.view_count - ifnull(t2.view_count, 0)),
+            t1.vote_increase = (t1.vote_count - ifnull(t2.vote_count, 0))
+        WHERE t1.`date` = curdate();
+    </update>
+
+</mapper>
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