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

Nested Class Summary

Nested classes/interfaces inherited from class com.sun.akuma.Daemon

Daemon.WithoutChdir

Field Summary

Fields

Modifier and Type	Field	Description
protected java.util.List<java.lang.String>	arguments	Java arguments.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NetworkServer(java.lang.String[] args)

Method Summary

Modifier and Type	Method	Description
protected abstract java.net.ServerSocket	createServerSocket()	Creates a bound ServerSocket that will be shared by all worker processes.
protected abstract void	forkWorkers(JavaVMArguments args)	Forks the worker thread with the given JVM args.
protected void	forkWorkerThreads(JavaVMArguments arguments, int n)	Called by the front-end code to fork a number of worker processes into the background.
protected void	frontend()	Front-end.
void	run()	Entry point.
protected boolean	shouldBeDaemonized()	Determine if we should daemonize ourselves.
protected void	worker()
protected abstract void	worker(java.net.ServerSocket ss)	Worker thread main code.

Methods inherited from class com.sun.akuma.Daemon

all, chdirToRoot, closeDescriptors, daemonize, daemonize, getCurrentExecutable, init, init, isDaemonized, selfExec, writePidFile

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

arguments

protected final java.util.List<java.lang.String> arguments

Java arguments.

Constructor Detail

NetworkServer

protected NetworkServer(java.lang.String[] args)

Method Detail

run

public void run()
         throws java.lang.Exception

Entry point. Should be called from your main method.

Throws:

java.lang.Exception

shouldBeDaemonized

protected boolean shouldBeDaemonized()

Determine if we should daemonize ourselves.

frontend

protected void frontend()
                 throws java.lang.Exception

Front-end.

Throws:

java.lang.Exception

forkWorkers

protected abstract void forkWorkers(JavaVMArguments args)
                             throws java.lang.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:

java.lang.Exception

forkWorkerThreads

protected void forkWorkerThreads(JavaVMArguments arguments,
                                 int n)
                          throws java.lang.Exception

Called by the front-end code to fork a number of worker processes into the background. This method never returns.

Throws:

java.lang.Exception

createServerSocket

protected abstract java.net.ServerSocket createServerSocket()
                                                     throws java.lang.Exception

Creates a bound ServerSocket that will be shared by all worker processes. This method is called in the frontend process.

Throws:

java.lang.Exception

worker

protected void worker()
               throws java.lang.Exception

Throws:

java.lang.Exception

worker

protected abstract void worker(java.net.ServerSocket ss)
                        throws java.lang.Exception

Worker thread main code.

Parameters:

ss - The server socket that the frontend process created.

Throws:

java.lang.Exception