What is jboss netty

Sets the minimum amount of time value in millis an object may sit idle in the pool before it is eligible for eviction by the idle object evictor. Allows to configure the Netty ServerBootstrap options using a org.

NettyServerBootstrapConfiguration instance. This can be used to reuse the same configuration for multiple consumers, to align their configuration more easily.

BossPool as the boss thread pool. For example to share a thread pool with multiple consumers. By default each consumer has their own boss pool with 1 core thread. WorkerPool as the worker thread pool. By default each consumer has their own worker pool with 2 x cpu count core threads. ChannelGroup —for example to broadact a message to multiple channels. When using UDP then this option can be used to specify a network interface by its name, such as eth0 to join a multicast group.

This option supports connectionless UDP sending, which is genuine fire-and-forget. The values that could be passed in, are the following:. Defaults to "SunX" if not set. Is loaded by default from classpath, but you can prefix with "classpath:" , "file:" , or "http:" to load the resource from different systems. Must override org. You can use a String which have values separated by comma, and have the values be looked up in the Registry. Just remember to prefix the value with so Camel knows it should lookup.

With no decoder defined Netty will default to serialized Java objects via the ObjectDecoder class; if a different format is expected then a decoder must be specified. ChannelHandlerFactory interface, and return a new instance in the newChannelHandler method.

The Netty component offers a org. ChannelHandlerFactories factory class, that has a number of commonly used methods. The producer mode supports both one-way and request-response based operations.

The consumer mode supports both one-way and request-response based operations. The following headers are filled for the exchanges created by the Netty consumer:. MessageEvent MessageEvent instance associated with the connection received by Netty. SocketAddress Remote address of the incoming socket connection. SocketAddress Local address of the incoming socket connection.

If failed, we print the cause of the failure to know why it failed. Now that the connection attempt is over, we need to wait until the connection is closed by waiting for the closeFuture of the Channel. Every Channel has its own closeFuture so that you are notified and can perform a certain action on closure.

Even if the connection attempt has failed the closeFuture will be notified because the Channel will be closed automatically when the connection attempt fails. All connections have been closed at this point.

The only task left is to release the resources being used by ChannelFactory. It is as simple as calling its releaseExternalResources method. All resources including the NIO Selector s and thread pools will be shut down and terminated automatically. Shutting down a client was pretty easy, but how about shutting down a server?

You need to unbind from the port and close all open accepted connections. To do this, you need a data structure that keeps track of the list of active connections, and it's not a trivial task. Fortunately, there is a solution, ChannelGroup. If a Channel is added to a ChannelGroup and the added Channel is closed, the closed Channel is removed from its ChannelGroup automatically. You can also perform an operation on all Channel s in the same group. For instance, you can close all Channel s in a ChannelGroup when you shut down your server.

Yes, ChannelGroup is thread-safe. Now that the list of all active Channel s are maintained automatically, shutting down a server is as easy as shutting down a client:. DefaultChannelGroup requires the name of the group as a constructor parameter. The group name is solely used to distinguish one group from others.

The bind method of ServerBootstrap returns a server side Channel which is bound to the specified local address. Calling the close method of the returned Channel will make the Channel unbind from the bound local address. Any type of Channel s can be added to a ChannelGroup regardless if it is either server side, client-side, or accepted.

Therefore, you can close the bound Channel along with the accepted Channel s in one shot when the server shuts down. You could wait for a message from a privileged client or the JVM shutdown hook. You can perform the same operation on all channels in the same ChannelGroup. In this case, we close all channels, which means the bound server-side Channel will be unbound and all accepted connections will be closed asynchronously. To notify when all connections were closed successfully, it returns a ChannelGroupFuture which has a similar role with ChannelFuture.

In this chapter, we had a quick tour of Netty with a demonstration on how to write a fully working network application on top of Netty. More questions you may have will be covered in the upcoming chapters and the revised version of this chapter.

Please also note that the community is always waiting for your questions and ideas to help you and keep improving Netty based on your feed back. In this chapter, we will examine what core functionalities are provided in Netty and how they constitute a complete network application development stack on top of the core. Please keep this diagram in mind as you read this chapter. This approach has significant advantages over using ByteBuffer.

Netty's new buffer type, ChannelBuffer has been designed from the ground up to address the problems of ByteBuffer and to meet the daily needs of network application developers.

To list a few cool features:. A dynamic buffer type is provided out-of-the-box, whose capacity is expanded on demand, just like StringBuffer. For more information, please refer to the org. For example, java. Socket and java. This mismatch makes porting a network application from one transport to another tedious and difficult. The lack of portability between transports becomes a problem when you need to support additional transports, as this often entails rewriting the network layer of the application.

Because all these APIs are different from each other in design and performance characteristics, you are often forced to determine which API your application will depend on before you even begin the implementation phase. For instance, you might want to start with OIO because the number of clients you are going to serve will be very small and writing a socket server using OIO is much easier than using NIO. However, you are going to be in trouble when your business grows exponentially and your server needs to serve tens of thousands of clients simultaneously.

That is, once you wrote your application on one Netty transport, your application can run on other Netty transports. Netty provides a number of essential transports via one universal API:.

Switching from one transport to another usually takes just a couple lines of changes such as choosing a different ChannelFactory implementation. Also, you are even able to take advantage of new transports which aren't yet written such as serial port communication transport , again by replacing just a couple lines of constructor calls.

Moreover, you can write your own transport by extending the core API. A well-defined and extensible event model is a must for an event-driven application. It also allows you to implement your own event type without breaking the existing code because each event type is distinguished from another by a strict type hierarchy.

This is another differentiator against other frameworks. Many NIO frameworks have no or a very limited notion of an event model. If they offer extension at all, they often break the existing code when you try to add custom event types. The pipeline implements an advanced form of the Intercepting Filter pattern to give a user full control over how an event is handled and how the handlers in the pipeline interact with each other.

For example, you can define what to do when data is read from a socket:. On top of the core components mentioned above, that already enable the implementation of all types of network applications, Netty provides a set of advanced features to accelerate the page of development even more. As demonstrated in Section 1. However, there are some complications when implementing this idea from scratch.

You have to deal with the fragmentation of messages. Some protocols are multi-layered i. Some are too complicated to be implemented in a single state machine. Consequently, a good network application framework should provide an extensible, reusable, unit-testable, and multi-layered codec framework that generates maintainable user codecs.

Netty provides a number of basic and advanced codecs to address most issues you will encounter when you write a protocol codec regardless if it is simple or not, binary or text - simply whatever. You can't simply wrap a stream to encrypt or decrypt data but you have to use javax. You have to manage all possible states such as cipher suite and encryption key negotiation or re-negotiation , certificate exchange, and validation.

Moreover, SSLEngine is not even completely thread-safe, as one would expect. All you need to do is to configure the SslHandler and insert it into your ChannelPipeline. It also allows you to implement advanced features like StartTLS very easily. HTTP is definitely the most popular protocol in the Internet.

It gives you complete control over how HTTP messages are exchanged at a low level. That is, you can write your own HTTP client or server that works exactly the way you want. You have full control over everything that's in the HTTP specification, including the thread model, connection life cycle, and chunked encoding.

Thanks to its highly customizable nature, you can write a very efficient HTTP server such as:. Chat server that requires persistent connections and server push technology e. Comet and WebSockets. Media streaming server that needs to keep the connection open until the whole media is streamed e. File server that allows the uploading of large files without memory pressure e.

Scalable mash-up client that connects to tens of thousands of 3rd party web services asynchronously. Google Protocol Buffers are an ideal solution for the rapid implementation of a highly efficient binary protocols that evolve over time. Please take a look into the 'LocalTime' example that shows how easily you can create a high-performing binary protocol client and server from the sample protocol definition.

In this chapter, we reviewed the overall architecture of Netty from the feature standpoint. Simplistic abstract classes which help implement encoder and decoder that transform an object into another object and vice versa. Encoder, decoder and their compatibility stream implementations which transform a Serializable object into a byte buffer and vice versa.

Encoder and decoder which transform a String into a ChannelBuffer and vice versa. Logs a ChannelEvent for debugging purpose using an InternalLogger. DingLi DingLi 9 9 silver badges 19 19 bronze badges. Add a comment. Active Oldest Votes.

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