MyBatis框架提供了二级缓存接口，我们只需要实现它再开启配置就可以使用了。
特别注意，我们要解决缓存穿透、缓存穿透和缓存雪崩的问题，同时也要保证缓存性能。
具体实现说明，直接看代码注释吧！
1、开启配置
SpringBoot配置
mybatis: configuration: cache-enabled: true
2、Redis配置以及服务接口
RedisConfig.java
package com.leven.mybatis.api.config;
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
@Configuration
public class RedisConfig {
@Bean
public RedisTemplate redisTemplate(RedisConnectionFactory redisConnectionFactory) {
RedisTemplate template = new RedisTemplate<>();
template.setConnectionFactory(redisConnectionFactory);
// 使用Jackson2JsonRedisSerializer来序列化和反序列化redis的value值
Jackson2JsonRedisSerializer
RedisService.java
package com.leven.mybatis.core.service;
import java.util.*;
import java.util.concurrent.TimeUnit;
public interface RedisService {
// =============================common============================
void expire(String key, long time);
void expireAt(String key, Date expireAt);
Long getExpire(String key);
Boolean hasKey(String key);
void delete(String... key);
void delete(Collection keys);
// ============================String=============================
Object get(String key);
void set(String key, Object value);
void set(String key, Object value, long time);
void set(String key, Object value, long time, TimeUnit timeUnit);
Long incr(String key, long value);
Long decr(String key, long value);
// ================================Map=================================
Object hashGet(String key, String item);
Map hashEntries(String key);
void hashSet(String key, Map map);
void hashSet(String key, Map map, long time);
void hashSet(String key, String item, Object value);
void hashSet(String key, String item, Object value, long time);
void hashDelete(String key, Object... item);
void hashDelete(String key, Collection items);
Boolean hashHasKey(String key, String item);
Double hashIncr(String key, String item, double value);
Double hashDecr(String key, String item, double value);
// ============================set=============================
Set
RedisServiceImpl.java
package com.leven.mybatis.core.service.impl;
import com.leven.commons.model.exception.SPIException;
import com.leven.mybatis.model.constant.Constant;
import com.leven.mybatis.core.service.RedisService;
import com.leven.mybatis.model.constant.ExceptionCode;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;
import java.util.*;
import java.util.concurrent.TimeUnit;
@Slf4j
@Service
public class RedisServiceImpl implements RedisService {
private static final String PREFIX = Constant.APPLICATION;
@Autowired
private RedisTemplate redisTemplate;
// =============================common============================
@Override
public void expire(String key, long time) {
redisTemplate.expire(getKey(key), time, TimeUnit.SECONDS);
}
@Override
public void expireAt(String key, Date expireAt) {
redisTemplate.expireAt(getKey(key), expireAt);
}
@Override
public Long getExpire(String key) {
return redisTemplate.getExpire(getKey(key), TimeUnit.SECONDS);
}
@Override
public Boolean hasKey(String key) {
return redisTemplate.hasKey(getKey(key));
}
@Override
public void delete(String... keys) {
if (keys != null && keys.length > 0) {
if (keys.length == 1) {
redisTemplate.delete(getKey(keys[0]));
} else {
List keyList = new ArrayList<>(keys.length);
for (String key : keys) {
keyList.add(getKey(key));
}
redisTemplate.delete(keyList);
}
}
}
@Override
public void delete(Collection keys) {
if (keys != null && !keys.isEmpty()) {
List keyList = new ArrayList<>(keys.size());
for (String key : keys) {
keyList.add(getKey(key));
}
redisTemplate.delete(keyList);
}
}
// ============================String=============================
@Override
public Object get(String key) {
return key == null ? null : redisTemplate.opsForValue().get(getKey(key));
}
@Override
public void set(String key, Object value) {
redisTemplate.opsForValue().set(getKey(key), value);
}
@Override
public void set(String key, Object value, long time) {
set(key, value, time, TimeUnit.SECONDS);
}
@Override
public void set(String key, Object value, long time, TimeUnit timeUnit) {
if (time > 0) {
redisTemplate.opsForValue().set(getKey(key), value, time, timeUnit);
} else {
set(getKey(key), value);
}
}
@Override
public Long incr(String key, long value) {
if (value < 1) {
throw new SPIException(ExceptionCode.RUNTIME_UNITE_EXP,"递增因子必须大于0");
}
return redisTemplate.opsForValue().increment(getKey(key), value);
}
@Override
public Long decr(String key, long value) {
if (value < 1) {
throw new SPIException(ExceptionCode.RUNTIME_UNITE_EXP,"递减因子必须大于0");
}
return redisTemplate.opsForValue().decrement(getKey(key), value);
}
// ================================Map=================================
@Override
public Object hashGet(String key, String item) {
return redisTemplate.opsForHash().get(getKey(key), item);
}
@Override
public Map hashEntries(String key) {
return redisTemplate.opsForHash().entries(getKey(key));
}
@Override
public void hashSet(String key, Map map) {
redisTemplate.opsForHash().putAll(getKey(key), map);
}
@Override
public void hashSet(String key, Map map, long time) {
String k = getKey(key);
redisTemplate.opsForHash().putAll(k, map);
if (time > 0) {
expire(k, time);
}
}
@Override
public void hashSet(String key, String item, Object value) {
redisTemplate.opsForHash().putIfAbsent(getKey(key), item, value);
}
@Override
public void hashSet(String key, String item, Object value, long time) {
String k = getKey(key);
redisTemplate.opsForHash().putIfAbsent(k, item, value);
if (time > 0) {
expire(k, time);
}
}
@Override
public void hashDelete(String key, Object... item) {
redisTemplate.opsForHash().delete(getKey(key), item);
}
@Override
public void hashDelete(String key, Collection items) {
redisTemplate.opsForHash().delete(getKey(key), items.toArray());
}
@Override
public Boolean hashHasKey(String key, String item) {
return redisTemplate.opsForHash().hasKey(getKey(key), item);
}
@Override
public Double hashIncr(String key, String item, double value) {
if (value < 1) {
throw new SPIException(ExceptionCode.RUNTIME_UNITE_EXP,"递增因子必须大于0");
}
return redisTemplate.opsForHash().increment(getKey(key), item, value);
}
@Override
public Double hashDecr(String key, String item, double value) {
if (value < 1) {
throw new SPIException(ExceptionCode.RUNTIME_UNITE_EXP,"递减因子必须大于0");
}
return redisTemplate.opsForHash().increment(getKey(key), item, -value);
}
// ============================set=============================
@Override
public Set
3、实现MyBatis的Cache接口
MybatisRedisCache.java
package com.leven.mybatis.core.cache;
import com.leven.commons.core.util.ApplicationContextUtils;
import com.leven.commons.model.exception.SPIException;
import com.leven.mybatis.core.service.RedisService;
import com.leven.mybatis.model.constant.ExceptionCode;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.RandomUtils;
import org.apache.ibatis.cache.Cache;
import java.security.MessageDigest;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
@Slf4j
public class MybatisRedisCache implements Cache {
private static final String CHARSET = "utf-8";
private static final String ALGORITHM = "SHA-256";
private static final String CACHE_NAME = "MyBatis:";
private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
private final String id;
private static volatile RedisService redisService;
private volatile MessageDigest messageDigest;
/////////////////////// 解决缓存雪崩，具体范围根据业务需要设置合理值 //////////////////////////
private static final int MIN_EXPIRE_MINUTES = 60;
private static final int MAX_EXPIRE_MINUTES = 120;
public MybatisRedisCache(String id) {
if (id == null) {
throw new IllegalArgumentException("Cache instances require an ID");
}
this.id = id;
}
@Override
public String getId() {
return id;
}
@Override
public void putObject(Object key, Object value) {
try {
String strKey = getKey(key);
// 有效期为1~2小时之间随机，防止雪崩
int expireMinutes = RandomUtils.nextInt(MIN_EXPIRE_MINUTES, MAX_EXPIRE_MINUTES);
getRedisService().set(strKey, value, expireMinutes, TimeUnit.MINUTES);
log.debug("Put cache to redis, id={}", id);
} catch (Exception e) {
log.error("Redis put failed, id=" + id, e);
}
}
@Override
public Object getObject(Object key) {
try {
String strKey = getKey(key);
log.debug("Get cache from redis, id={}", id);
return getRedisService().get(strKey);
} catch (Exception e) {
log.error("Redis get failed, fail over to db", e);
return null;
}
}
@Override
public Object removeObject(Object key) {
try {
String strKey = getKey(key);
getRedisService().delete(strKey);
log.debug("Remove cache from redis, id={}", id);
} catch (Exception e) {
log.error("Redis remove failed", e);
}
return null;
}
@Override
public void clear() {
try {
log.debug("clear cache, id={}", id);
String hsKey = CACHE_NAME + id;
// 获取CacheNamespace所有缓存key
Map idMap = getRedisService().hashEntries(hsKey);
if (!idMap.isEmpty()) {
Set
到此这篇关于MyBatis整合Redis实现二级缓存的示例代码的文章就介绍到这了,更多相关MyBatis整合Redis二级缓存内容请搜索考高分网以前的文章或继续浏览下面的相关文章希望大家以后多多支持考高分网！
