EVCache缓存在Spring Boot中的实战示例

git clone git@github.com:Netflix/EVCache.git

 ./gradlew build
Downloading https://services.gradle.org/distributions/gradle-2.10-bin.zip
.................................................................................................................................

...

:evcache-client:check
:evcache-client:build
:evcache-client-sample:writeLicenseHeader
:evcache-client-sample:licenseMain
Missing header in: evcache-client-sample/src/main/java/com/netflix/evcache/sample/EVCacheClientSample.java
:evcache-client-sample:licenseTest UP-TO-DATE
:evcache-client-sample:license
:evcache-client-sample:compileTestJava UP-TO-DATE
:evcache-client-sample:processTestResources UP-TO-DATE
:evcache-client-sample:testClasses UP-TO-DATE
:evcache-client-sample:test UP-TO-DATE
:evcache-client-sample:check
:evcache-client-sample:build

BUILD SUCCESSFUL

Total time: 22.866 secs

<dependency>
  <groupId>com.netflix.evcache</groupId>
  <artifactId>evcache-client</artifactId>
  <version>4.137.0-SNAPSHOT</version>
</dependency>

public class EVCacheClient {

  private final EVCache evCache;  // 关键角色在此

  public EVCacheClient() {
    String deploymentDescriptor = System.getenv("EVC_SAMPLE_DEPLOYMENT");
    if ( deploymentDescriptor == null ) {
      deploymentDescriptor = "SERVERGROUP1=192.168.199.77:11211;SERVERGROUP2=192.168.199.78:11211";
    }
    System.setProperty("EVCACHE_APP1.use.simple.node.list.provider", "true");
    System.setProperty("EVCACHE_APP1-NODES", deploymentDescriptor);
    evCache = new EVCache.Builder().setAppName("EVCACHE_APP1").build();
  }

  public void setKey(String key, String value, int timeToLive) throws Exception {
    try {
      Future<Boolean>[] _future = evCache.set(key, value, timeToLive);
      for (Future<Boolean> f : _future) {
        boolean didSucceed = f.get();
        // System.out.println("per-shard set success code for key " + key + " is " + didSucceed);
        // 此处可以针对 didSucceed做相应判断
      }
      System.out.println("finished setting key " + key);
    } catch (EVCacheException e) {
      e.printStackTrace();
    }
  }

  public String getKey(String key) {
    try {
      String _response = evCache.<String>get(key);
      return _response;
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }

}

@Configuration
public class EVCacheConfig {

  @Bean
  public EVCacheClient evcacheClient() {
    EVCacheClient evCacheClient = new EVCacheClient();
    return evCacheClient;
  }
}

@Service
public class EVCacheService {

  @Autowired
  private EVCacheClient evCacheClient;

  public void setKey( String key, String value, int timeToLive ) {
    try {
      evCacheClient.setKey( key, value, timeToLive );
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  public String getKey( String key ) {
    return evCacheClient.getKey( key );
  }
}

@RestController
public class EVCacheTestController {

  @Autowired
  private EVCacheService evCacheService;

  @GetMapping("/testevcache")
  public void testEvcache() {

    try {

      for ( int i = 0; i < 10; i++ ) {
        String key = "key_" + i;
        String value = "data_" + i;
        int ttl = 180;      // 此处将缓存设为三分钟（180s）生存期，时间一过，缓存即会失效
        evCacheService.setKey(key, value, ttl);
      }

      for (int i = 0; i < 10; i++) {
        String key = "key_" + i;
        String value = evCacheService.getKey(key);
        System.out.println("Get of " + key + " returned " + value);
      }
      
    } catch (Exception e) {
      e.printStackTrace();
    }

  }
}

[root@localhost ~]# telnet 127.0.0.1 11211
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
get key_0
VALUE key_0 0 6
data_0
END
get key_1
VALUE key_1 0 6
data_1
END
get key_2    
VALUE key_2 0 6
data_2
END
get key_3
VALUE key_3 0 6
data_3
END
get key_4
VALUE key_4 0 6
data_4
END
get key_5
VALUE key_5 0 6
data_5
END
get key_6
VALUE key_6 0 6
data_6
END
get key_7
VALUE key_7 0 6
data_7
END
get key_8
VALUE key_8 0 6
data_8
END
get key_9
VALUE key_9 0 6
data_9
END