Package com.sun.akuma

Class NetworkServer

java.lang.Object
com.sun.akuma.Daemon
com.sun.akuma.NetworkServer
Direct Known Subclasses:
EchoServer
public abstract class NetworkServer extends Daemon
Multi-process network server that accepts connections on the same TCP port.

This class lets you write a Unix-like multi-process network daemon. The first process acts as the frontend. This creates a new socket, then fork several worker processes, which inherits this socket.

Worker threads will all accept connections on this port, so even when one of the worker processes die off, your clients won't notice that there's a problem.

The user of this class needs to override this class and implement abstract methods. Several protected methods can be also overridden to customize the behaviors. See EchoServer source code as an example.

This class also inherits from Daemon to support the daemonization.

From your main method, call into run() method. Depending on whether the current process is started as a front end or a worker process, the run method behave accordingly.

Author:
Kohsuke Kawaguchi

  • Field Details

    • arguments

      protected final List<String> arguments
      Java arguments.

  • Constructor Details

    • NetworkServer

      protected NetworkServer(String[] args)

  • Method Details

    • run

      public void run() throws Exception
      Entry point. Should be called from your main method.
      Throws:
      Exception

    • shouldBeDaemonized

      protected boolean shouldBeDaemonized()
      Determine if we should daemonize ourselves.

    • frontend

      protected void frontend() throws Exception
      Front-end.
      Throws:
      Exception

    • forkWorkers

      protected abstract void forkWorkers(JavaVMArguments args) throws Exception
      Forks the worker thread with the given JVM args. The implementation is expected to modify the arguments to suit their need, then call into forkWorkerThreads(JavaVMArguments, int).
      Throws:
      Exception

    • forkWorkerThreads

      protected void forkWorkerThreads(JavaVMArguments arguments, int n) throws Exception
      Called by the front-end code to fork a number of worker processes into the background. This method never returns.
      Throws:
      Exception

    • createServerSocket

      protected abstract ServerSocket createServerSocket() throws Exception
      Creates a bound ServerSocket that will be shared by all worker processes. This method is called in the frontend process.
      Throws:
      Exception

    • worker

      protected void worker() throws Exception
      Throws:
      Exception

    • worker

      protected abstract void worker(ServerSocket ss) throws Exception
      Worker thread main code.
      Parameters:
      ss - The server socket that the frontend process created.
      Throws:
      Exception