Package jade.core

Class BaseService

    • Constructor Detail

      • BaseService

        public BaseService()

    • Method Detail

      • init

        public void init​(AgentContainer ac,
                 Profile p)
          throws ProfileException
        Description copied from interface: Service
        Performs the passive initialization step of the service. This method is called before activating the service. Its role should be simply the one of a constructor, setting up the internal data as needed. Service implementations should not use the Service Manager and Service Finder facilities from within this method. A distributed initialization protocol, if needed, should be exectuted within the boot() method.
        Specified by:
        init in interface Service
        Parameters:
        ac - The agent container this service is activated on.
        p - The configuration profile for this service.
        Throws:
        ProfileException - If the given profile is not valid.

      • getSlice

        public Service.Slice getSlice​(String name)
                       throws ServiceException
        The getSlice() implementation of this class works as follows:
        1. First, the name alias table is used to convert the given slice name into another name, if any
        2. Then, the new name (which may or may not be different from the original one) is used to look up an internal table keeping the service slices
        3. If no slice was found, the ServiceFinder is asked to provide the slice, which is then put into the local table.
        Specified by:
        getSlice in interface Service
        Parameters:
        name - A name for the requested slice. The name must be unique within this service.
        Returns:
        The Slice object that is a part of this service and is identified by the given name, or null if no such slice exists.
        Throws:
        ServiceException - If some underlying error (e.g. a network problem) occurs, that does not allow to decide whether the requested slice exists or not.

      • getNumberOfSlices

        public int getNumberOfSlices()
        This method returns the current number of slices known to this service on this node. Due to the distributed nature of many JADE services, there is no guaranteed that calling this method for the same service on different nodes will actually result on the same number.
        Specified by:
        getNumberOfSlices in interface Service
        Returns:
        The number of slices of this service that are known to this node.

      • getAllSlices

        public Service.Slice[] getAllSlices()
                             throws ServiceException
        The getAllSlices() implementation of this class directly retrieves the current list of slices from the Service Manager. Note that slices are retrieved directly from the Main and not from the cache.
        Specified by:
        getAllSlices in interface Service
        Returns:
        An array of Service.Slice objects, whose elements are the slices of this service deployed at the different platform nodes.
        Throws:
        ServiceException - If some underlying error (e.g. a network problem) occurs, that does not allow to retrieve the full slice list.

      • addAlias

        protected void addAlias​(String alias,
                        String name)
        This protected method allows subclasses to define their own naming schemes, by adding aliases for existing slice names.
        Parameters:
        alias - The new alias name.
        name - The real name this alias must be mapped to.

      • lookupAlias

        protected String lookupAlias​(String alias)
        This protected method is used by getSlice() to dereference aliases for slice names. Subclasses can override this method to build their own service-specific naming schema.
        Parameters:
        alias - The alias name to map to a real slice name.
        Returns:
        A mapped name, or the original one if no mapping was found.

      • getCommandFilter

        public Filter getCommandFilter​(boolean direction)
        This should be properly implemented by the services that have filters. Note that when called multiple times with the same value of the direction parameter this method MUST always return the same object!
        Specified by:
        getCommandFilter in interface Service
        Parameters:
        direction - One of the two constants Filter.INCOMING and Filter.OUTGOING, distinguishing between the two filter chains managed by the command processor.
        Returns:
        A Filter object, used by this service to intercept and process kernel-level commands. If the service does not wish to install a command filter for one or both directions, it can just return null when appropriate.
        See Also:
        CommandProcessor

      • getCommandSink

        public Sink getCommandSink​(boolean direction)
        This should be properly implemented by the services that have sinks.
        Specified by:
        getCommandSink in interface Service
        Parameters:
        direction - One of the two constants Sink.COMMAND_SOURCE or Sink.COMMAND_TARGET, to state whether this sink will handle locally issued commands or commands incoming from remote nodes.
        Returns:
        Concrete services must return their own implementation of the Sink interface, that will be invoked by the kernel in order to consume any incoming vertical command owned by this service. If the service does not wish to install a command sink, it can just return null.
        See Also:
        Service.getOwnedCommands()

      • getOwnedCommands

        public String[] getOwnedCommands()
        This should be properly implemented by the services that owns vertival commands.
        Specified by:
        getOwnedCommands in interface Service
        Returns:
        An array containing the names of all the vertical commands this service wants to own. If this service has no such commands (it acts purely as a command filter), it can return an empty array, or null as well.
        See Also:
        jade.core.Service#getCommandSink()

      • getHorizontalInterface

        public Class getHorizontalInterface()
        This should be properly implemented by the services that have non-empty slices.
        Specified by:
        getHorizontalInterface in interface Service
        Returns:
        A Class object, representing the interface that is implemented by the slices of this service. Let s be the Class object corresponding to the Service.Slice interface, and let c be the returned Class object. Then, the two following conditions must hold:
        1. c.isInterface() == true
        2. s.isAssignableFrom(c) == true

      • getLocalSlice

        public Service.Slice getLocalSlice()
        This should be properly implemented by the services that have non-empty slices.
        Specified by:
        getLocalSlice in interface Service
        Returns:
        The slice of this service that resides on the local platform node, or null if no such slice exists.

      • isLocal

        public boolean isLocal()

      • getAMSBehaviour

        public Behaviour getAMSBehaviour()
        This should be properly implemented by the services that require a service specific Behaviour running in the AMS.
        Specified by:
        getAMSBehaviour in interface Service
        Returns:
        A Behaviour object associated with this service, or null if no such behaviour exists.

      • boot

        public void boot​(Profile p)
          throws ServiceException
        Description copied from interface: Service
        Performs the active initialization step of a kernel-level service. When JADE kernel calls this method, the service has already been already associated with its container and registered with the Service Manager.
        Specified by:
        boot in interface Service
        Parameters:
        p - The configuration profile for this service.
        Throws:
        ServiceException - If a problem occurs during service initialization.

      • shutdown

        public void shutdown()
        Description copied from interface: Service
        Performs the shutdown step of a kernel-level service. The JADE kernel calls this method just before uninstalling this service
        Specified by:
        shutdown in interface Service

      • submit

        public Object submit​(VerticalCommand cmd)
              throws ServiceException
        Description copied from interface: Service
        Allows submitting a vertical command for processing. The given vertical command must be owned by this service (i.e. its name must be one of the constants contained in the array returned by getOwnedCommands(), or an exception is thrown
        Specified by:
        submit in interface Service
        Parameters:
        cmd - The command to submit to the service.
        Returns:
        The result of the command, or null if this command produced no result. If an exception was produced, it will not be thrown, but will be returned as well.
        Throws:
        ServiceException - If the passed command does not belong to this service.

      • getIMTPManager

        protected IMTPManager getIMTPManager()

      • clearCachedSlice

        protected void clearCachedSlice​(String name)

      • dump

        public String dump​(String key)
        This method can be redefined to support service internal data inspection by means of the ContainerMonitorAgent included in the misc add-on. The default implementation just dumps the map of cached slices
        Parameters:
        key - A hint indicating which service data should be dumped
        Returns:
        A string representation of the service internal data