elasticsearch client 为空 错误信息：java.lang.NoSuchMethodError: com.google.common.util.concurrent.MoreExecutors.directExecut‌​or()Ljava/util/concu‌​rrent/Executor

错误信息：java.lang.NoSuchMethodError: com.google.common.util.concurrent.MoreExecutors.directExecut‌​or()Ljava/util/concu‌​rrent/Executor

现象：创建ES客户端连接失败

解决：maven引入高版本的guava

例如elasticsearch2.3.1使用guava18

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>18.0</version>
</dependency>