mybatisplus使用Caffeine作为mapper层二级缓存

小咪咪 2022-09-12 10:47 192阅读 0赞

引入Caffeine

<dependency>
                <groupId>com.github.ben-manes.caffeine</groupId>
                <artifactId>caffeine</artifactId>
                <version>2.9.0</version>
            </dependency>

封装好的工具类：

package com.ciih.authcenter.client.util;
    
    import com.github.benmanes.caffeine.cache.Cache;
    import com.github.benmanes.caffeine.cache.Caffeine;
    import org.springframework.stereotype.Component;
    
    import java.util.concurrent.TimeUnit;
    import java.util.function.Function;
    
    /**
     * 缓存之王
     *
     * @author Lenovo
     */
    @Component
    public class CaffeineService {
    
        private Cache<Object, Object> cache;
    
        public CaffeineService() {
            this.cache = Caffeine.newBuilder()
                    //过期策略:一分钟没有读取,则过期删除
                    .expireAfterWrite(1, TimeUnit.MINUTES)
                    //允许容量100个,超过自动删除
                    .maximumSize(100)
                    .build();
        }
    
        /**
         * 存储K-V
         *
         * @param key
         * @param value
         * @return
         */
        public Object put(Object key, Object value) {
            cache.put(key, value);
            return key;
        }
    
        /**
         * 获取K-V
         *
         * @param key
         * @return
         */
        public Object getIfPresent(Object key) {
            return cache.getIfPresent(key);
        }
    
        public Object get(Object key, Function<Object, Object> function) {
            return cache.get(key, function);
        }
    
        public void remove(Object key) {
            cache.invalidate(key);
        }
    
        public void cleanUp() {
            cache.cleanUp();
        }
    
        public long estimatedSize() {
            return cache.estimatedSize();
        }
    }

Mybatis缓存实现类

import cn.hutool.extra.spring.SpringUtil;
    import com.ciih.authcenter.client.util.CaffeineService;
    import lombok.extern.slf4j.Slf4j;
    import org.apache.ibatis.cache.Cache;
    
    import java.util.concurrent.locks.ReadWriteLock;
    import java.util.concurrent.locks.ReentrantReadWriteLock;
    
    /**
     * 二级缓存实现
     *
     * @author Lenovo
     */
    @Slf4j
    public class MybatisCache implements Cache {
    
        private CaffeineService caffeineService;
    
        private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock(true);
    
        private String id;
    
        public MybatisCache(final String id) {
            if (id == null) {
                throw new IllegalArgumentException("Cache instances require an ID");
            }
            this.id = id;
        }
    
        @Override
        public String getId() {
            return this.id;
        }
    
    
        @Override
        public void putObject(Object key, Object value) {
            if (caffeineService == null) {
                caffeineService = SpringUtil.getBean(CaffeineService.class);
            }
            if (value != null) {
                caffeineService.put(key, value);
            }
        }
    
        @Override
        public Object getObject(Object key) {
            if (caffeineService == null) {
                caffeineService = SpringUtil.getBean(CaffeineService.class);
            }
            try {
                if (key != null) {
                    return caffeineService.getIfPresent(key);
                }
            } catch (Exception e) {
                log.error("缓存出错 ");
            }
            return null;
        }
    
        /**
         * As of 3.3.0 this method is only called during a rollback
         * for any previous value that was missing in the cache.
         * This lets any blocking cache to release the lock that
         * may have previously put on the key.
         * A blocking cache puts a lock when a value is null
         * and releases it when the value is back again.
         * This way other threads will wait for the value to be
         * available instead of hitting the database.
         *
         * @param key The key
         * @return Not used
         */
        @Override
        public Object removeObject(Object key) {
            if (caffeineService == null) {
                caffeineService = SpringUtil.getBean(CaffeineService.class);
            }
            caffeineService.remove(key);
            return null;
        }
    
        /**
         * Clears this cache instance.
         */
        @Override
        public void clear() {
            if (caffeineService == null) {
                caffeineService = SpringUtil.getBean(CaffeineService.class);
            }
            caffeineService.cleanUp();
        }
    
        /**
         * Optional. This method is not called by the core.
         *
         * @return The number of elements stored in the cache (not its capacity).
         */
        @Override
        public int getSize() {
            if (caffeineService == null) {
                caffeineService = SpringUtil.getBean(CaffeineService.class);
            }
            return (int) caffeineService.estimatedSize();
        }
    
        /**
         * Optional. As of 3.2.6 this method is no longer called by the core.
         * <p>
         * Any locking needed by the cache must be provided internally by the cache provider.
         *
         * @return A ReadWriteLock
         */
        @Override
        public ReadWriteLock getReadWriteLock() {
            return this.readWriteLock;
        }
    }

配置一下Dao接口

@CacheNamespace(implementation= MybatisCache.class,eviction=MybatisCache.class)
    public interface SchoolDao extends EasyBaseMapper<School> {
        
    }

配置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="com.ciih.authcenter.client.dao.SchoolDao">
        <cache-ref namespace="com.ciih.authcenter.client.dao.SchoolDao"/>
    
    </mapper>