[Java] 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

接下来我们结合 spring工程，来实战一下 evcache client的具体使用。

• 192.168.199.77:11211
  
• 192.168.199.78:11211
  

<dependency>
  <groupid>com.netflix.evcache</groupid>
  <artifactid>evcache-client</artifactid>
  <version>4.137.0-snapshot</version>
</dependency>

注：我将 spring工程设置在 8899端口启动

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();
  }
 
  }
}

注意此处是向每个后端 memcached缓存实例中都写入了 10条测试数据

[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