spring cache定义了缓存接口，redis则作为缓存的实现
1.引入 spring cache 和 redis
<!-- spring boot-->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.0.RELEASE</version>
<relativePath/>
</parent>
<!-- spring cache -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<!-- redis -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!-- 为了解决 ClassNotFoundException: org.apache.commons.pool2.impl.GenericObjectPoolConfig -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
<version>2.5.0</version>
</dependency>
2. yaml配置
spring:
redis:
#数据库索引
database: 0
host: 127.0.0.1
port: 6379
password:
#连接超时时间
timeout: 5000
3.redis缓存配置类
package me.zhengjie.config;
import cn.hutool.core.lang.Assert;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.parser.ParserConfig;
import com.alibaba.fastjson.serializer.SerializerFeature;
import lombok.extern.slf4j.Slf4j;
import me.zhengjie.utils.StringUtils;
import org.apache.commons.codec.digest.DigestUtils;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.data.redis.RedisProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cache.Cache;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.interceptor.CacheErrorHandler;
import org.springframework.cache.interceptor.KeyGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.util.HashMap;
import java.util.Map;
/**
* 缓存配置类
* @date 2018-11-24
*/
@Slf4j
@Configuration
@EnableCaching
@ConditionalOnClass(RedisOperations.class)
@EnableConfigurationProperties(RedisProperties.class)
public class RedisConfig extends CachingConfigurerSupport {
/**
* 设置 redis 数据默认过期时间，默认6小时
* 设置@cacheable 序列化方式
*/
@Bean
public RedisCacheConfiguration redisCacheConfiguration(){
FastJsonRedisSerializer<Object> fastJsonRedisSerializer = new FastJsonRedisSerializer<>(Object.class);
RedisCacheConfiguration configuration = RedisCacheConfiguration.defaultCacheConfig();
configuration = configuration.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(fastJsonRedisSerializer)).entryTtl(Duration.ofHours(6));
return configuration;
}
@Bean(name = "redisTemplate")
@ConditionalOnMissingBean(name = "redisTemplate")
public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
RedisTemplate<Object, Object> template = new RedisTemplate<>();
//序列化
FastJsonRedisSerializer<Object> fastJsonRedisSerializer = new FastJsonRedisSerializer<>(Object.class);
// value值的序列化采用fastJsonRedisSerializer
template.setValueSerializer(fastJsonRedisSerializer);
template.setHashValueSerializer(fastJsonRedisSerializer);
// 全局开启AutoType，这里方便开发，使用全局的方式
ParserConfig.getGlobalInstance().setAutoTypeSupport(true);
// 建议使用这种方式，小范围指定白名单
// ParserConfig.getGlobalInstance().addAccept("me.zhengjie.domain");
// ParserConfig.getGlobalInstance().addAccept("me.zhengjie.modules.system.service.dto");
// ParserConfig.getGlobalInstance().addAccept("me.zhengjie.service.dto");
// ParserConfig.getGlobalInstance().addAccept("me.zhengjie.modules.system.domain");
// ParserConfig.getGlobalInstance().addAccept("me.zhengjie.modules.quartz.domain");
// ParserConfig.getGlobalInstance().addAccept("me.zhengjie.modules.monitor.domain");
// ParserConfig.getGlobalInstance().addAccept("me.zhengjie.modules.security.security");
// key的序列化采用StringRedisSerializer
template.setKeySerializer(new StringRedisSerializer());
template.setHashKeySerializer(new StringRedisSerializer());
template.setConnectionFactory(redisConnectionFactory);
return template;
}
/**
* 自定义缓存key生成策略，默认将使用该策略
*/
@Bean
@Override
public KeyGenerator keyGenerator() {
return (target, method, params) -> {
Map<String,Object> container = new HashMap<>();
Class<?> targetClassClass = target.getClass();
// 类地址
container.put("class",targetClassClass.toGenericString());
// 方法名称
container.put("methodName",method.getName());
// 包名称
container.put("package",targetClassClass.getPackage());
// 参数列表
for (int i = 0; i < params.length; i++) {
container.put(String.valueOf(i),params[i]);
}
// 转为JSON字符串
String jsonString = JSON.toJSONString(container);
// 做SHA256 Hash计算，得到一个SHA256摘要作为Key
return DigestUtils.sha256Hex(jsonString);
};
}
@Bean
@Override
public CacheErrorHandler errorHandler() {
// 异常处理，当Redis发生异常时，打印日志，但是程序正常走
log.info("初始化 -> [{}]", "Redis CacheErrorHandler");
return new CacheErrorHandler() {
@Override
public void handleCacheGetError(RuntimeException e, Cache cache, Object key) {
log.error("Redis occur handleCacheGetError：key -> [{}]", key, e);
}
@Override
public void handleCachePutError(RuntimeException e, Cache cache, Object key, Object value) {
log.error("Redis occur handleCachePutError：key -> [{}]；value -> [{}]", key, value, e);
}
@Override
public void handleCacheEvictError(RuntimeException e, Cache cache, Object key) {
log.error("Redis occur handleCacheEvictError：key -> [{}]", key, e);
}
@Override
public void handleCacheClearError(RuntimeException e, Cache cache) {
log.error("Redis occur handleCacheClearError：", e);
}
};
}
}
/**
* Value 序列化
*
* @author /
* @param <T>
*/
class FastJsonRedisSerializer<T> implements RedisSerializer<T> {
private Class<T> clazz;
FastJsonRedisSerializer(Class<T> clazz) {
super();
this.clazz = clazz;
}
@Override
public byte[] serialize(T t) {
if (t == null) {
return new byte[0];
}
return JSON.toJSONString(t, SerializerFeature.WriteClassName).getBytes(StandardCharsets.UTF_8);
}
@Override
public T deserialize(byte[] bytes) {
if (bytes == null || bytes.length <= 0) {
return null;
}
String str = new String(bytes, StandardCharsets.UTF_8);
return JSON.parseObject(str, clazz);
}
}
/**
* 重写序列化器
*
* @author /
*/
class StringRedisSerializer implements RedisSerializer<Object> {
private final Charset charset;
StringRedisSerializer() {
this(StandardCharsets.UTF_8);
}
private StringRedisSerializer(Charset charset) {
Assert.notNull(charset, "Charset must not be null!");
this.charset = charset;
}
@Override
public String deserialize(byte[] bytes) {
return (bytes == null ? null : new String(bytes, charset));
}
@Override
public byte[] serialize(Object object) {
String string = JSON.toJSONString(object);
if (StringUtils.isBlank(string)) {
return null;
}
string = string.replace("\"", "");
return string.getBytes(charset);
}
}
4.service层缓存注解
@Service
@CacheConfig(cacheNames = "user")
@Transactional(propagation = Propagation.SUPPORTS, readOnly = true, rollbackFor = Exception.class)
public class UserServiceImpl implements UserService {
@Override
@Cacheable
public List<UserDTO> queryAll(UserQueryCriteria criteria) {
List<User> users = userRepository.findAll((root, criteriaQuery, criteriaBuilder) -> QueryHelp.getPredicate(root,criteria,criteriaBuilder));
return userMapper.toDto(users);
}
}
5.生成的缓存展示
5.1 从可视化redis客户端查询展示
[图片上传失败...(image-137e9f-1591627344874)]
5.2 从dos客户端查询展示
[图片上传失败...(image-2f98e7-1591627344874)]
6.注解说明
- @Cacheable:触发缓存写入。
- @CacheEvict:触发缓存清除。
- @CachePut:更新缓存(不会影响到方法的运行)。
- @Caching:重新组合要应用于方法的多个缓存操作。
- @CacheConfig:设置类级别上共享的一些常见缓存设置。
网友评论