## Using the shaded JAR The default driver JAR depends on [Netty](http://netty.io/), which is used internally for networking. This explicit dependency can be a problem if your application already uses another Netty version. To avoid conflicts, we provide a "shaded" version of the JAR, which bundles the Netty classes under a different package name: ```xml <dependency> <groupId>com.datastax.cassandra</groupId> <artifactId>cassandra-driver-core</artifactId> <version>3.4.0</version> <classifier>shaded</classifier> <!-- Because the shaded JAR uses the original POM, you still need to exclude this dependency explicitly: --> <exclusions> <exclusion> <groupId>io.netty</groupId> <artifactId>*</artifactId> </exclusion> </exclusions> </dependency> ``` If you also use the mapper, you need to remove its dependency to the non-shaded JAR: ```xml <dependency> <groupId>com.datastax.cassandra</groupId> <artifactId>cassandra-driver-core</artifactId> <version>3.4.0</version> <classifier>shaded</classifier> <exclusions> <exclusion> <groupId>io.netty</groupId> <artifactId>*</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>com.datastax.cassandra</groupId> <artifactId>cassandra-driver-mapping</artifactId> <version>3.4.0</version> <exclusions> <exclusion> <groupId>com.datastax.cassandra</groupId> <artifactId>cassandra-driver-core</artifactId> </exclusion> </exclusions> </dependency> ``` ### Limitations When using the shaded jar, it is not possible to configure the Netty layer. Extending [NettyOptions] is not an option because `NettyOptions` API exposes Netty classes, and as such it should only be extended by clients using the non-shaded version of driver. Attempting to extend `NettyOptions` with shaded Netty classes is not supported, and in particular for OSGi applications, it is likely that such a configuration would lead to compile and/or runtime errors. Also, with shaded Netty classes, it is not possible to benefit from [Netty native transports]. It is therefore normal to see the following log line when the driver starts and detects that shaded Netty classes are being used: Detected shaded Netty classes in the classpath; native epoll transport will not work properly, defaulting to NIO. [NettyOptions]:http://docs.datastax.com/en/drivers/java/3.4/com/datastax/driver/core/NettyOptions.html [Netty native transports]:http://netty.io/wiki/native-transports.html