[jetcache] jetcache configuration description and annotation attribute description

Contents of this article

One 、 Configuration instructions

Two 、 Annotation property description  

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One 、 Configuration instructions

yml Profile case （ If not used springboot, Direct configuration GlobalCacheConfig It's similar , Refer to the quick start tutorial ）：

jetcache:
  statIntervalMinutes: 15
  areaInCacheName: false
  hidePackages: com.alibaba
  local:
    default:
      type: caffeine
      limit: 100
      keyConvertor: fastjson
      expireAfterWriteInMillis: 100000
    otherArea:
      type: linkedhashmap
      limit: 100
      keyConvertor: none
      expireAfterWriteInMillis: 100000
  remote:
    default:
      type: redis
      keyConvertor: fastjson
      valueEncoder: java
      valueDecoder: java
      poolConfig:
        minIdle: 5
        maxIdle: 20
        maxTotal: 50
      host: ${redis.host}
      port: ${redis.port}
    otherArea:
      type: redis
      keyConvertor: fastjson
      valueEncoder: kryo
      valueDecoder: kryo
      poolConfig:
        minIdle: 5
        maxIdle: 20
        maxTotal: 50
      host: ${redis.host}
      port: ${redis.port}

The general description of the configuration is as follows ：

attribute	The default value is	explain
jetcache.statIntervalMinutes	0	Statistical interval ,0 Indicates no statistics
jetcache.areaInCacheName	true	jetcache-anno hold cacheName As a remote cache key Prefix ,2.4.3 Previous versions always put areaName Add to cacheName in , therefore areaName It also appears in key In the prefix .2.4.4 It can be configured later , In order to stay remote key The compatible default is true, But for new projects false More reasonable .
jetcache.hiddenPackages	nothing	@Cached and @CreateCache Automatic generation name When , In order not to let name Too long ,hiddenPackages The specified package name prefix is truncated
jetcache.[local|remote].${area}.type	nothing	Cache type .tair、redis For the currently supported remote cache ;linkedhashmap、caffeine Is the currently supported local cache type
jetcache.[local|remote].${area}.keyConvertor	nothing	key Global configuration of the converter , At present, there is only one implemented keyConvertor：fastjson. Only when using @CreateCache And the cache type is LOCAL Can be specified as none, At this point through equals Methods to identify key. Method cache must specify keyConvertor
jetcache.[local|remote].${area}.valueEncoder	java	Global configuration of serializer . only remote Type of cache needs to be specified , Optional java and kryo
jetcache.[local|remote].${area}.valueDecoder	java	Global configuration of serializer . only remote Type of cache needs to be specified , Optional java and kryo
jetcache.[local|remote].${area}.limit	100	Global configuration of the largest element per cache instance , only local Type of cache needs to be specified . Note the limitations of each cache instance , Not all of them , For example, here we specify 100, And then use @CreateCache Created two cache instances （ And the annotation is not set localLimit attribute ）, Then the limit of each cache instance is 100
jetcache.[local|remote].${area}.expireAfterWriteInMillis	infinity	Global configuration that specifies the timeout in milliseconds ( Used to be defaultExpireInMillis)
jetcache.local.${area}.expireAfterAccessInMillis	0	need jetcache2.2 above , In Milliseconds , Specify how long you haven't visited , Just invalidate the cache , Currently, only local cache supports .0 Indicates that this function is not used .

The above table ${area} Corresponding @Cached and @CreateCache Of area attribute . Note that if the annotation does not specify area, The default value is "default".

About cache timeout , There are multiple places to specify , To clarify ：

1. put And so on , Then this time shall prevail
2. put The timeout method is not specified , Use Cache The default timeout of the instance
3. Cache The default timeout of the instance , By means of @CreateCache and @Cached Upper expire Attribute specifies , If not specified , Use yml Global configuration defined in , for example @Cached(cacheType=local) Use jetcache.local.default.expireAfterWriteInMillis, If not specified, it is infinite

Two 、 Annotation property description  

JetCache Method cache and SpringCache similar , It provides TTL Support , To ensure final agreement , And support L2 cache .JetCache2.4 Support annotation based cache update and deletion in the future .

stay spring In the environment , Use @Cached Annotations can add caching to a method ,@CacheUpdate For updating the cache ,@CacheInvalidate Used to remove cache elements . Annotations can be added to interfaces or classes , The annotated class must be a spring bean, for example ：

public interface UserService {
    @Cached(name="userCache.", key="#userId", expire = 3600)
    User getUserById(long userId);

    @CacheUpdate(name="userCache.", key="#user.userId", value="#user")
    void updateUser(User user);

    @CacheInvalidate(name="userCache.", key="#userId")
    void deleteUser(long userId);
}

key Use Spring Of SpEL Script to specify . If you want to use parameter names （ Like here key="#userId"）, Project compilation settings target It has to be for 1.8 Format , And specify javac Of -parameters Parameters , Otherwise, use key="args[0]" This is in the form of subscript access .

@CacheUpdate and @CacheInvalidate Of name and area Property must be the same as @Cached identical ,name Attributes can also be used as cache Of key Prefix .

@Cached Notes and @CreateCache The properties of are very similar , But a few more ：

attribute	The default value is	explain
area	“default”	If multiple caches are configured in the configuration area, Specify which... To use here area
name	Undefined	Specifies the unique name of the cache , It's not necessary , If not specified , Can use class name + Method name .name Will be used for remote caching key Prefix . In addition, in Statistics , A short and meaningful name will improve readability .
key	Undefined	Use SpEL Appoint key, If not specified, it will be automatically generated according to all parameters .
expire	Undefined	Timeout time . If there is no definition in the annotation , Will use global configuration , If the global configuration is not defined at this time , It's infinity
timeUnit	TimeUnit.SECONDS	Appoint expire The unit of
cacheType	CacheType.REMOTE	The type of cache , Include CacheType.REMOTE、CacheType.LOCAL、CacheType.BOTH. If defined as BOTH, Will use LOCAL and REMOTE Combined into two-level cache
localLimit	Undefined	If cacheType by LOCAL or BOTH, This parameter specifies the maximum number of elements in the local cache , To control memory usage . If there is no definition in the annotation , Will use global configuration , If the global configuration is not defined at this time , Then for 100
localExpire	Undefined	Only when the cacheType by BOTH When applicable , In memory Cache Specify a different timeout , Usually it should be less than expire
serialPolicy	Undefined	Specifies how the remote cache is serialized . Optional value is SerialPolicy.JAVA and SerialPolicy.KRYO. If there is no definition in the annotation , Will use global configuration , If the global configuration is not defined at this time , Then for SerialPolicy.JAVA
keyConvertor	Undefined	Appoint KEY The transformation of , Used to convert complex KEY Type is converted to a type acceptable to the cache implementation , The current support KeyConvertor.FASTJSON and KeyConvertor.NONE.NONE It means no conversion ,FASTJSON Complex objects can be KEY convert to String. If there is no definition in the annotation , Will use global configuration .
enabled	true	Whether to activate cache . For example, a dao Add cache annotation to the method , Because there can be no cache in some call scenarios , So you can set enabled by false, Normal calls do not use the cache , Can be used where needed CacheContext.enableCache Activate the cache in the callback , Cache active tags in ThreadLocal On , After this flag is set , all enable=false All caches are activated
cacheNullValue	false	When the return value of the method is null Whether to cache when
condition	Undefined	Use SpEL Specified conditions , If the expression returns true Only go to the cache to query
postCondition	Undefined	Use SpEL Specified conditions , If the expression returns true Only update the cache when , The evaluation is carried out after the implementation of the method , So you can access #result

@CacheInvalidate Note that ：

attribute	The default value is	explain
area	“default”	If multiple caches are configured in the configuration area, Specify which... To use here area, Pointing to corresponding @Cached Definition .
name	Undefined	Specifies the unique name of the cache , Pointing to corresponding @Cached Definition .
key	Undefined	Use SpEL Appoint key
condition	Undefined	Use SpEL Specified conditions , If the expression returns true To delete , Accessible method results #result

@CacheUpdate Note that ：

attribute	The default value is	explain
area	“default”	If multiple caches are configured in the configuration area, Specify which... To use here area, Pointing to corresponding @Cached Definition .
name	Undefined	Specifies the unique name of the cache , Pointing to corresponding @Cached Definition .
key	Undefined	Use SpEL Appoint key
value	Undefined	Use SpEL Appoint value
condition	Undefined	Use SpEL Specified conditions , If the expression returns true To perform the update , Accessible method results #result

Use @CacheUpdate and @CacheInvalidate When , Related cache operations may fail （ Such as network IO error ）, Therefore, it is very important to specify the timeout of the cache .

@CacheRefresh Note that ：

attribute	The default value is	explain
refresh	Undefined	Refresh interval
timeUnit	TimeUnit.SECONDS	Time unit
stopRefreshAfterLastAccess	Undefined	Specify the key How long does it take to stop refreshing without access , If not specified, it will always refresh
refreshLockTimeout	60 second	The type is BOTH/REMOTE Cache refresh for , At the same time, only one server will be refreshing , This server will place a distributed lock in the remote cache , This configuration specifies the timeout of the lock

@CachePenetrationProtect annotation ：

When cache access misses , Protect concurrent loading behavior . The current version implements a single JVM The protection inside , Is the same JVM The same one key There is only one thread to load , Other threads wait for results .

For parameters with no default values defined above , If not specified , Will use yml Global configuration specified in , For global configuration, please refer to Configuration instructions .

 

The end ！