Class Daemon

  • All Implemented Interfaces:
    java.lang.Runnable

    public abstract class Daemon
    extends java.lang.Object
    implements java.lang.Runnable
    The Daemon object provides a named daemon thread which will execute the run method when started. This offers some convenience in that it hides the normal thread methods and also allows the object extending this to provide the name of the internal thread, which is given an incrementing sequence number appended to the name provided.
    Author:
    Niall Gallagher
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected Daemon()
      Constructor for the Daemon object.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String getName()
      This is used to acquire the name of the thread.
      void interrupt()
      This is used to interrupt the internal thread.
      boolean isStarted()
      This is used to determine if the daemon has already started.
      void join()
      This is used to join with the internal thread of this daemon.
      void start()
      This is used to start the internal thread.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
      • Methods inherited from interface java.lang.Runnable

        run
    • Constructor Detail

      • Daemon

        protected Daemon()
        Constructor for the Daemon object. This will create the internal thread and ensure it is a daemon. When it is started the name of the internal thread is set using the name of the instance as taken from getName. If the name provided is null then no name is set for the thread.
    • Method Detail

      • start

        public void start()
        This is used to start the internal thread. Once started the internal thread will execute the run method of this instance. Aside from starting the thread this will also ensure the internal thread has a unique name.
      • isStarted

        public boolean isStarted()
        This is used to determine if the daemon has already started. Once started it can not be started again. This ensures that when dead it remains dead. The contract of this method is that if the start method is invoked at any point this method will always return true.
        Returns:
        true if the daemon has already been started
      • interrupt

        public void interrupt()
        This is used to interrupt the internal thread. This is used when there is a need to wake the thread from a sleeping or waiting state so that some other operation can be performed. Typically this is required when killing the thread.
      • join

        public void join()
                  throws java.lang.InterruptedException
        This is used to join with the internal thread of this daemon. Rather than exposing the internal thread a join method is provided. This allows asynchronous threads to wait for the daemon to complete simulating synchronous action.
        Throws:
        java.lang.InterruptedException - if the thread is interrupted
      • getName

        public java.lang.String getName()
        This is used to acquire the name of the thread. This will be overridden by instances that wish to provide a descriptive name for the thread. If this is not overridden then the name of the thread is the simple name of the implementation.
        Returns:
        the name of the internal thread executed