缓存来了

在dotnet平台有自己的缓存框架，在java springboot里当然了集成了很多，而且缓存的中间件也可以进行多种选择，向redis, hazelcast都是分布式的缓存中间件，今天主要说一下后者的实现。

添加依赖包

dependencies {
    compile("org.springframework.boot:spring-boot-starter-cache")
    compile("com.hazelcast:hazelcast:3.7.4")
    compile("com.hazelcast:hazelcast-spring:3.7.4")
}
bootRun {
    systemProperty "spring.profiles.active", "hazelcast-cache"
}

config统一配置

@Configuration
@Profile("hazelcast-cache")//运行环境名称
public class HazelcastCacheConfig {

  @Bean
  public Config hazelCastConfig() {

    Config config = new Config();
    config.setInstanceName("hazelcast-cache");

    MapConfig allUsersCache = new MapConfig();
    allUsersCache.setTimeToLiveSeconds(3600);
    allUsersCache.setEvictionPolicy(EvictionPolicy.LFU);
    config.getMapConfigs().put("alluserscache", allUsersCache);

    MapConfig usercache = new MapConfig();
    usercache.setTimeToLiveSeconds(3600);//超时时间为1小时
    usercache.setEvictionPolicy(EvictionPolicy.LFU);
    config.getMapConfigs().put("usercache", usercache);//usercache为缓存的cachename

    return config;
  }

}

添加仓储

public interface UserRepository {

  List<UserInfo> fetchAllUsers();

  List<UserInfo> fetchAllUsers(String name);
}


@Repository
@Profile("hazelcast-cache")// 指定在这个hazelcast-cache环境下，UserRepository的实例才是UserInfoRepositoryHazelcast
public class UserInfoRepositoryHazelcast implements UserRepository {

  @Override
  @Cacheable(cacheNames = "usercache", key = "#root.methodName")// 无参的方法，方法名作为key
  public List<UserInfo> fetchAllUsers(){
    List<UserInfo> list = new ArrayList<>();
    list.add(UserInfo.builder().phone("135").userName("zzl1").createAt(LocalDateTime.now()).build());
    list.add(UserInfo.builder().phone("136").userName("zzl2").createAt(LocalDateTime.now()).build());
    return list;
  }
  @Override
  @Cacheable(cacheNames = "usercache", key = "{#name}") // 方法名和参数组合做为key
  public List<UserInfo> fetchAllUsers(String name) {
    List<UserInfo> list = new ArrayList<>();
    list.add(UserInfo.builder().phone("135").userName("zzl1").createAt(LocalDateTime.now()).build());
    list.add(UserInfo.builder().phone("136").userName("zzl2").createAt(LocalDateTime.now()).build());
    return list;
  }
}

配置profile

application.yml开启这个缓存的环境

  profiles.active: hazelcast-cache

运行程序

可以在单元测试里进行测试，调用多次，方法体只进入一次，这就是缓存成功了。

@ActiveProfiles("hazelcast-cache")
public class UserControllerTest extends BaseControllerTest {
  @Test
  public void fetchUsers() {
    getOk();
    //test caching
    getOk();
  }

  private WebTestClient.ResponseSpec getOk() {
    return http.get()
        .uri("/users/all/zzl")
        .exchange()
        .expectStatus().isOk();
  }
}