readme.MD

introduction

JetCache is a Java cache abstraction which provides consistent use for various caching solutions. Presently There are four implements: RedisCache, TairCache(not open source on github), CaffeineCache (in memory), a simple LinkedHashMapCache (in memory). Features of JetCache:

• Operate cache through consistent Cache API.
• Declarative method caching using annotation with TTL(Time To Live) and two level caching support
• Create & configure Cache instance using annotation
• Auto collect access statistics for Cache instance and method cache
• The policy of key generation and value serialization can be customized
• Distributed cache auto refresh and distributed lock. (2.2+)
• Asynchronous access using Cache API (2.2+, with redis lettuce client)
• Spring Boot support

requirements:

• JDK1.8
• Spring Framework4.0.8+ (optional, with annotation support)
• Spring Boot1.1.9+ (optional)

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getting started

method cache

Declare method cache using @Cached annotation.
expire = 3600 indicates that the elements will expires in 3600 seconds after put. JetCache auto generates cache key using all parameters.

public interface UserService {
    @Cached(expire = 3600, cacheType = CacheType.REMOTE)
    User getUserById(long userId);
}

Using key attribute to specify cache key using SpEL script.

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);
    
    //compiler 
}

To enable use parameter name such as key="#userId", you javac compiler target must be 1.8 and the -parameters should be set, otherwise use index to access parameters like key="args[0]"

Automatically refresh:

public interface SummaryService{
    @Cached(expire = 3600, cacheType = CacheType.REMOTE)
    @CacheRefresh(refresh = 1800, stopRefreshAfterLastAccess = 3600, timeUnit = TimeUnit.SECONDS)
    BigDecimal summaryOfToday(long catagoryId);
}

cache API

Create a Cache instance using @CreateCache annotation:

@CreateCache(expire = 100, cacheType = CacheType.BOTH, localLimit = 50)
private Cache<Long, UserDO> userCache;

The code above create a Cache instance. cacheType = CacheType.BOTH define a two level cache (a local in-memory-cache and a remote cache system) with local elements limited upper to 50(LRU based evict). You can use it like a map:

UserDO user = userCache.get(12345L);
userCache.put(12345L, loadUserFromDataBase(12345L));
userCache.remove(12345L);

userCache.computeIfAbsent(1234567L, (key) -> loadUserFromDataBase(1234567L));

advanced API

Asynchronous API:

CacheGetResult r = cache.GET(userId);
CompletionStage<ResultData> future = r.future();
future.thenRun(() -> {
    if(r.isSuccess()){
        System.out.println(r.getValue());
    }
});

Distributed lock:

cache.tryLockAndRun("key", 60, TimeUnit.SECONDS, () -> heavyDatabaseOperation());

Read through and auto refresh:

@CreateCache
@CacheRefresh(timeUnit = TimeUnit.MINUTES, refresh = 60)
private Cache<String, Long> orderSumCache;

@PostConstruct
public void init(){
    orderSumCache.config().setLoader(this::loadOrderSumFromDatabase);
}

configuration with Spring Boot

pom:

<dependency>
    <groupId>com.alicp.jetcache</groupId>
    <artifactId>jetcache-starter-redis</artifactId>
    <version>${jetcache.latest.version}</version>
</dependency>

App class:

@SpringBootApplication
@EnableMethodCache(basePackages = "com.company.mypackage")
@EnableCreateCacheAnnotation
public class MySpringBootApp {
    public static void main(String[] args) {
        SpringApplication.run(MySpringBootApp.class);
    }
}

spring boot application.yml config:

jetcache:
  statIntervalMinutes: 15
  local:
    default:
      type: linkedhashmap
      keyConvertor: fastjson
      limit: 100
  remote:
    default:
      type: redis
      keyConvertor: fastjson
      valueEncoder: java
      valueDecoder: java
      poolConfig:
        minIdle: 5
        maxIdle: 20
        maxTotal: 50
      host: ${redis.host}
      port: ${redis.port}

more docs

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