Class ConcurrentServerRunner<T extends Client>

All Implemented Interfaces:
ServerRunner<T>, ContextAware, Runnable

public abstract class ConcurrentServerRunner<T extends Client> extends ContextAwareBase implements Runnable, ServerRunner<T>
A concurrent ServerRunner.

An instance of this object is created with a ServerListener and an Executor. On invocation of the start() method, it passes itself to the given Executor and returns immediately. On invocation of its run() method by the Executor it begins accepting client connections via its ServerListener. As each new Client is accepted, the client is configured with the runner's LoggingContext and is then passed to the Executor for concurrent execution of the client's service loop.

On invocation of the stop() method, the runner closes the listener and each of the connected clients (by invoking Client.close() effectively interrupting any blocked I/O calls and causing these concurrent subtasks to exit gracefully). This ensures that before the stop() method returns (1) all I/O resources have been released and (2) all of the threads of the Executor are idle.

Carl Harris
  • Constructor Details

    • ConcurrentServerRunner

      public ConcurrentServerRunner(ServerListener<T> listener, Executor executor)
      Constructs a new server runner.
      listener - the listener from which the server will accept new clients
      executor - an executor that will facilitate execution of the listening and client-handling tasks; while any Executor is allowed here, outside of unit testing the only reasonable choice is a bounded thread pool of some kind.
  • Method Details

    • isRunning

      public boolean isRunning()
      Gets a flag indicating whether the server is currently running.
      Specified by:
      isRunning in interface ServerRunner<T extends Client>
      flag state
    • setRunning

      protected void setRunning(boolean running)
    • stop

      public void stop() throws IOException
      Stops execution of the runner.

      This method must cause all I/O and thread resources associated with the runner to be released. If the receiver has not been started, this method must have no effect.

      Specified by:
      stop in interface ServerRunner<T extends Client>
    • accept

      public void accept(ClientVisitor<T> visitor)
      Presents each connected client to the given visitor.
      Specified by:
      accept in interface ServerRunner<T extends Client>
      visitor - the subject visitor
    • run

      public void run()
      Specified by:
      run in interface Runnable
    • configureClient

      protected abstract boolean configureClient(T client)
      Configures a connected client.

      A subclass implements this method to perform any necessary configuration of the client object before its method is invoked.

      client - the subject client
      true if configuration was successful; if the return value is false the client connection will be dropped