前言:
在系统中,有些数据,访问十分频繁,往往把这些数据放入分布式缓存中,但为了减少网络传输,加快响应速度,缓存分布式缓存读压力,会把这些数据缓存到本地JVM中,大多是先取本地缓存中,再取分布式缓存中的数据,Caffeine是一个高性能Java 缓存库,使用Java8对Guava缓存重写版本,在Spring Boot 2.0中将取代Guava
一、引入依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
<groupId>com.github.ben-manes.caffeine</groupId>
<artifactId>caffeine</artifactId>
<version>2.6.2</version>
</dependency>
二、开启缓存
主启动类添加注解@EnableCaching
三、Controller层
@RestController
public class CacheController {
@Autowired
CacheService cacheService;
@RequestMapping("cacheMethod01")
public String cacheMethod01(String key) {
return cacheService.cacheMethod01(key);
}
@RequestMapping("cacheMethod02")
public String cacheMethod02(String key) {
return cacheService.cacheMethod02(key);
}
}
四、Service层
@Service
public class CacheService {
@Cacheable(value = "cacheMethod01", key = "#key")
public String cacheMethod01(String key) {
System.out.println("cacheMethod01()方法执行,key="+key);
return "cacheMethod01...,key="+key;
}
@Cacheable(value = "cacheMethod02", key = "#key")
public String cacheMethod02(String key) {
System.out.println("cacheMethod02()方法执行,key="+key);
return "cacheMethod02...,key="+key;
}
}
五、消亡时间枚举类
public enum CacheType {
cacheMethod01(10),
cacheMethod02(5);
private int expires; // 消亡时间
CacheType(int expires) {
this.expires = expires;
}
public int getExpires() {
return expires;
}
}
六、配置类
@Configuration
public class CaffeineConfig {
@Bean
public CacheManager caffeineCacheManager() {
SimpleCacheManager cacheManager = new SimpleCacheManager();
List<CaffeineCache> caffeineCaches = new ArrayList<>();
for (CacheType cacheType : CacheType.values()) {
caffeineCaches.add(new CaffeineCache(cacheType.name(),
Caffeine.newBuilder()
.expireAfterWrite(cacheType.getExpires(), TimeUnit.SECONDS)
.build()));
}
cacheManager.setCaches(caffeineCaches);
return cacheManager;
}
}
七、配置文件(不推荐)
spring.cache.cache-names=cacheMethod01, cacheMethod02
spring.cache.caffeine.spec=initialCapacity=50,maximumSize=500,expireAfterWrite=5s
spring.cache.type=caffeine