特性
全部特性:
- 通过统一的API访问Cache系统
- 通过注解实现声明式的方法缓存，支持TTL和两级缓存
- 通过注解创建并配置
Cache实例 - 针对所有
Cache实例和方法缓存的自动统计 - Key的生成策略和Value的序列化策略是可以配置的
- 分布式缓存自动刷新，分布式锁 (2.2+)
- 异步Cache API (2.2+，使用Redis的lettuce客户端时)
- Spring Boot支持
JetCache整合srpingboot配置
maven配置
<!--注意版本要对应，不然会报错-->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<dependency>
<groupId>com.alicp.jetcache</groupId>
<artifactId>jetcache-starter-redis</artifactId>
<version>2.6.0</version>
</dependency>
<!--可能要加-->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<compilerArgument>-parameters</compilerArgument>
</configuration>
</plugin>
application.yml配置
jetcache:
statIntervalMinutes: 1
areaInCacheName: false
local:
default:
type: caffeine
limit: 100
keyConvertor: fastjson
remote:
default:
type: redis
keyConvertor: fastjson
valueEncoder: java
valueDecoder: java
poolConfig:
minIdle: 5
maxIdle: 20
maxTotal: 50
host: 47.98.129.125
port: 6379
#password:***
#sentinels: 127.0.0.1:26379 , 127.0.0.1:26380, 127.0.0.1:26381
#masterName: mymaster
使用JavaConfig配置（与application.yml配置二选一）
@Configuration
@EnableMethodCache(basePackages = "com.example.demo.cache")
@EnableCreateCacheAnnotation
public class JetCacheConfig {
@Bean
public Pool<Jedis> pool() {
GenericObjectPoolConfig pc = new GenericObjectPoolConfig();
pc.setMinIdle(2);
pc.setMaxIdle(10);
pc.setMaxTotal(10);
return new JedisPool(pc, "47.98.129.125", 6379);
}
@Bean
public ConfigProvider configProvider() {
return new ConfigProvider();
}
@Bean
public GlobalCacheConfig config( Pool<Jedis> pool) {
Map localBuilders = new HashMap();
EmbeddedCacheBuilder localBuilder = CaffeineCacheBuilder
.createCaffeineCacheBuilder()
.limit(100)
.keyConvertor(FastjsonKeyConvertor.INSTANCE);
localBuilders.put(CacheConsts.DEFAULT_AREA, localBuilder);
Map remoteBuilders = new HashMap();
RedisCacheBuilder remoteCacheBuilder = RedisCacheBuilder.createRedisCacheBuilder()
.keyConvertor(FastjsonKeyConvertor.INSTANCE)
.valueEncoder(JavaValueEncoder.INSTANCE)
.valueDecoder(JavaValueDecoder.INSTANCE)
.jedisPool(pool);
remoteBuilders.put(CacheConsts.DEFAULT_AREA, remoteCacheBuilder);
GlobalCacheConfig globalCacheConfig = new GlobalCacheConfig();
globalCacheConfig.setLocalCacheBuilders(localBuilders);
globalCacheConfig.setRemoteCacheBuilders(remoteBuilders);
globalCacheConfig.setStatIntervalMinutes(15);
globalCacheConfig.setAreaInCacheName(false);
return globalCacheConfig;
}
}
常用注解
启动类上加注解，开启缓存：
@EnableMethodCache(proxyTargetClass = true,basePackages = "com.shinemo.migu.activity.thirdapi.core")
@EnableCreateCacheAnnotation
方法上的注解
获取时：
@Cached(name = "award.getById", key = "#id", cacheType = CacheType.LOCAL, expire = 300)
修改时:
@CacheUpdate(name="userCache-", key="#user.userId", value="#user")
void updateUser(UserDO user);
删除时：
@CacheInvalidate(name = "userService2.getUserById", key = "#id")
代码示例：
@Service
public class UserService2 {
@Autowired
private UserDao userDao;
@Cached(name = "userService2.getUserById", key = "#id", cacheType = CacheType.BOTH, expire = 60*5)
@CacheRefresh(refresh = 10, stopRefreshAfterLastAccess = 60)
public UserDO getUserById(Integer id) {
UserDO userDO = userDao.selectById(id);
return userDO;
}
public void addUser(UserDO user) {
userDao.insert(user);
}
@CacheUpdate(name = "userService2.getUserById", key = "#user.id",value = "#user" )
public void updateUser(UserDO user) {
userDao.updateById(user);
}
@CacheInvalidate(name = "userService2.getUserById", key = "#id")
public void deleteUser(Integer id) {
//userDao.deleteById(id);
}
}
实例变量上的注解
创建缓存实例：
@CreateCache(cacheType = CacheType.LOCAL, name = "jobActivityCache", timeUnit = TimeUnit.MINUTES, expire = 5)
private Cache<Integer,UserDO> userCache;
@CreateCache(name = "UserService.userCache", expire = 100, cacheType = CacheType.BOTH, localLimit = 50)
private Cache<Long, UserDO> userCache;
代码示例：
@Service
public class UserService {
@CreateCache(name = "UserService.userCache", cacheType = CacheType.REMOTE, localLimit = 50,expire = 60*5)
private Cache<Integer, UserDO> userCache;
@Autowired
private UserDao userDao;
public UserDO getUserById(Integer id) {
UserDO userDO = userCache.get(id);
if (userDO == null) {
UserDO userDB = userDao.selectById(id);
if (userDB == null) {
throw new RuntimeException("数据不存在");
}
userCache.put(id, userDB);
return userDB;
}
return userDO;
}
public void addUser(UserDO user) {
userDao.insert(user);
}
public void updateUser(UserDO user) {
userDao.updateById(user);
userCache.put(user.getId(), user);
}
public void deleteUser(Integer id) {
//userDao.deleteById(id);
userCache.remove(id);
}
}
刷新缓存
@CacheRefresh
刷新缓存,可以加在方法上，也可以加在实例上：
@CacheRefresh(refresh = 60, stopRefreshAfterLastAccess = 300) //60秒刷新一次，如果300秒内没有访问，则停止刷新
cacheType为REMOTE或者BOTH的时候，刷新行为是全局唯一的，也就是说，即使应用服务器是一个集群，也不会出现多个服务器同时去刷新一个key的情况。
一个key的刷新任务，自该key首次被访问后初始化，如果该key长时间不被访问，在stopRefreshAfterLastAccess指定的时间后，相关的刷新任务就会被自动移除，这样就避免了浪费资源去进行没有意义的刷新。
@CachePenetrationProtect
@CachePenetrationProtect表示在多线程环境中同步加载数据。
高级API
异步API
CacheGetResult r = cache.GET(userId);
CompletionStage<ResultData> future = r.future();
future.thenRun(() -> {
if(r.isSuccess()){
System.out.println(r.getValue());
}
});
分布式锁
cache.tryLockAndRun("key", 60, TimeUnit.SECONDS, () -> heavyDatabaseOperation());
设置读取器并自动刷新
@CreateCache(name = "UserService3.userCache",timeUnit = TimeUnit.SECONDS,expire = 1000,cacheType = CacheType.BOTH)
@CacheRefresh(timeUnit = TimeUnit.SECONDS, refresh = 30, stopRefreshAfterLastAccess = 600)
@CachePenetrationProtect
private Cache<String, List<UserDO>> userCache;
@PostConstruct
public void init(){
userCache.config().setLoader(this::loadUser);
}
public List<UserDO> loadUser(String key) {
List<UserDO> userDOS = userDao.selectList(null);
return userDOS;
}