Java 8 和 MyBatis 框架实现每天凌晨 2 点进行增量缓存

以下是使用 Java 8 和 MyBatis 框架实现每天凌晨 2 点进行增量缓存的完整示例代码：

Offering 实体类：
public class Offering {
private String id;
private String name;
private String size;
private String type;

// 构造方法、getter 和 setter
}
OfferingMapper 接口：
import java.util.List;

public interface OfferingMapper {
List<Offering> getAllOfferings();
List<Offering> getIncrementalOfferings();
}
OfferingMapper.xml（MyBatis 的 XML 配置文件）：
<?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="your.package.OfferingMapper">

<select id="getAllOfferings" resultType="Offering">
SELECT id, name, size, type FROM offering
</select>

<select id="getIncrementalOfferings" resultType="Offering">
SELECT id, name, size, type FROM offering WHERE last_update_date > CURDATE()
</select>

</mapper>
OfferingCache 类（实现缓存和定时任务）：
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import redis.clients.jedis.Jedis;

public class OfferingCache {

public static void main(String[] args) {
try {
// 加载 MyBatis 配置文件
String resource = "mybatis-config.xml";
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(OfferingCache.class.getClassLoader().getResourceAsStream(resource));

// 连接 Redis
Jedis jedis = new Jedis("localhost");

// 第一次全量缓存
SqlSession session = sqlSessionFactory.openSession();
OfferingMapper offeringMapper = session.getMapper(OfferingMapper.class);
List<Offering> allOfferings = offeringMapper.getAllOfferings();
Map<String, String> dataToCache = new HashMap<>();
for (Offering offering : allOfferings) {
String value = offering.getName() + "," + offering.getSize() + "," + offering.getType();
dataToCache.put(offering.getId(), value);
}
for (Map.Entry<String, String> entry : dataToCache.entrySet()) {
jedis.hset("offering_key", entry.getKey(), entry.getValue());
}
session.close();

// 设置定时任务每天凌晨 2 点执行增量缓存
ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
scheduler.scheduleAtFixedRate(() -> {
try {
session = sqlSessionFactory.openSession();
offeringMapper = session.getMapper(OfferingMapper.class);
List<Offering> incrementalOfferings = offeringMapper.getIncrementalOfferings();
Map<String, String> incrementalData = new HashMap<>();
for (Offering offering : incrementalOfferings) {
String value = offering.getName() + "," + offering.getSize() + "," + offering.getType();
incrementalData.put(offering.getId(), value);
}
for (Map.Entry<String, String> entry : incrementalData.entrySet()) {
jedis.hset("offering_key", entry.getKey(), entry.getValue());
System.out.println("增量数据 ID: " + entry.getKey());
}
session.close();
} catch (Exception e) {
e.printStackTrace();
}
}, 0, 24, TimeUnit.HOURS);