org.xmlBlaster.contrib.mime
Class DropIfNotDeliverable

java.lang.Object
  org.xmlBlaster.contrib.mime.DropIfNotDeliverable

All Implemented Interfaces:

org.xmlBlaster.engine.mime.I_AccessFilter, org.xmlBlaster.util.dispatch.I_ConnectionStatusListener, org.xmlBlaster.util.plugin.I_Plugin

public class DropIfNotDeliverable

extends java.lang.Object

implements org.xmlBlaster.util.plugin.I_Plugin, org.xmlBlaster.engine.mime.I_AccessFilter, org.xmlBlaster.util.dispatch.I_ConnectionStatusListener

Throw away callback messages and unsubscribe all subscriptions if a client gows to polling.

If a client callback goes to polling, this plugin removes all existing subscriptions and clears all messages in the callback queue.
The client needs to add a filter Qos to its SubscribeQos to activate the plugin.
In a next step we could add configuration parameters to only remove specific subscriptions (and not remove other callback queue entries).

Configuration example (put to xmlBlaster.properties):

 MimeAccessPlugin[DropIfNotDeliverable][1.0]=\
   org.xmlBlaster.contrib.mime.DropIfNotDeliverable,dropper.types=*
 

dropper.types=* is default and activates the plugin for any published message where a subscriber has set this filter,
dropper.types=text/xml;application/xml would for example limit the plugin to such messages having his mime type declared on publish

A typical subscribeQos is for example:

<qos>
   <multiSubscribe>false</multiSubscribe>
   <local>false</local>
   <initialUpdate>false</initialUpdate>
   <updateOneway>false</updateOneway>
   <notify>false</notify>
   <persistent>false</persistent>
   <filter type='DropIfNotDeliverable'>
    <![CDATA[_]]>
   </filter>
</qos>
  

The query statement '_' is ignored by this plugin.

This plugin is a singleton and loaded once only for multiple subscribers configuring it

Author:

Marcel Ruff

See Also:

The mime.plugin.accessfilter requirement

Field Summary

static java.lang.String

MIME_TYPES

Constructor Summary

DropIfNotDeliverable()

Method Summary

java.lang.String[]	getMimeExtended() Get the content MIME version number for which this plugin applies
java.lang.String[]	getMimeTypes() Get the content MIME type for which this plugin applies, currently { "*" }.
java.lang.String	getName() Get a human readable name of this filter implementation
java.lang.String	getType() Return plugin type for Plugin loader
java.lang.String	getVersion() Return plugin version for Plugin loader
void	init(org.xmlBlaster.util.Global glob, org.xmlBlaster.util.plugin.PluginInfo pluginInfo) This method is called by the PluginManager (enforced by I_Plugin).
void	initialize(org.xmlBlaster.engine.ServerScope serverScope) This is called after instantiation of the plugin
boolean	match(org.xmlBlaster.authentication.SessionInfo receiver, org.xmlBlaster.util.MsgUnit msgUnit, org.xmlBlaster.engine.mime.Query query) Check if the filter rule matches for this message.
void	shutdown() Cleans up the resource.
void	toAlive(org.xmlBlaster.util.dispatch.DispatchManager dispatchManager, org.xmlBlaster.util.dispatch.ConnectionStateEnum oldState)
void	toDead(org.xmlBlaster.util.dispatch.DispatchManager dispatchManager, org.xmlBlaster.util.dispatch.ConnectionStateEnum oldState, java.lang.String errorText)
void	toPolling(org.xmlBlaster.util.dispatch.DispatchManager dispatchManager, org.xmlBlaster.util.dispatch.ConnectionStateEnum oldState)

Methods inherited from class java.lang.Object

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

Field Detail

MIME_TYPES

public static final java.lang.String MIME_TYPES

See Also:

Constant Field Values

Constructor Detail

DropIfNotDeliverable

public DropIfNotDeliverable()

Method Detail

initialize

public void initialize(org.xmlBlaster.engine.ServerScope serverScope)

This is called after instantiation of the plugin

Specified by:

initialize in interface org.xmlBlaster.engine.mime.I_AccessFilter

Parameters:

serverScope - The Global handle of this xmlBlaster server instance.

init

public void init(org.xmlBlaster.util.Global glob,
                 org.xmlBlaster.util.plugin.PluginInfo pluginInfo)
          throws org.xmlBlaster.util.XmlBlasterException

This method is called by the PluginManager (enforced by I_Plugin).

Specified by:

init in interface org.xmlBlaster.util.plugin.I_Plugin

Throws:

org.xmlBlaster.util.XmlBlasterException

See Also:

I_Plugin.init(org.xmlBlaster.util.Global,org.xmlBlaster.util.plugin.PluginInfo)

getType

public java.lang.String getType()

Return plugin type for Plugin loader

Specified by:

getType in interface org.xmlBlaster.util.plugin.I_Plugin

Returns:

"DropIfNotDeliverable"

getVersion

public java.lang.String getVersion()

Return plugin version for Plugin loader

Specified by:

getVersion in interface org.xmlBlaster.util.plugin.I_Plugin

Returns:

"1.0"

getName

public java.lang.String getName()

Get a human readable name of this filter implementation

Specified by:

getName in interface org.xmlBlaster.engine.mime.I_AccessFilter

Returns:

"DropIfNotDeliverable"

getMimeTypes

public java.lang.String[] getMimeTypes()

Get the content MIME type for which this plugin applies, currently { "*" }. Is configurable with dropper.types=text/xml;image/svg+xml;application/xml

Specified by:

getMimeTypes in interface org.xmlBlaster.engine.mime.I_AccessFilter

Returns:

{ "*" } This plugin handles all mime types

getMimeExtended

public java.lang.String[] getMimeExtended()

Get the content MIME version number for which this plugin applies

Specified by:

getMimeExtended in interface org.xmlBlaster.engine.mime.I_AccessFilter

Returns:

"1.0" (this is the default version number)

match

public boolean match(org.xmlBlaster.authentication.SessionInfo receiver,
                     org.xmlBlaster.util.MsgUnit msgUnit,
                     org.xmlBlaster.engine.mime.Query query)
              throws org.xmlBlaster.util.XmlBlasterException

Description copied from interface: org.xmlBlaster.engine.mime.I_AccessFilter

Check if the filter rule matches for this message.

Note that you are not allowed to manipulate the content or XmlKey or QoS of a message with your plugin as this would affect all other subscribers (you are working on a reference to the original message). You can find out the publisher name like msgUnit.getQosData().getSender()

Specified by:

match in interface org.xmlBlaster.engine.mime.I_AccessFilter

Parameters:

receiver - The session object describing the receiver, is never null.

msgUnit - The message to check, is never null.

query - The query containing the filter rule on subscribe/get usually the client defines his own rule which is passed here.
null: If for a subscribe() or get() no rule is given, your plugin needs to have its own general rule or react how it likes.
Access the raw query string with query.getQuery(), you can parse it and store the prepared query with query.setPreparedQuery() - query.getPreparedQuery() to increase performance.

Returns:

true If the filter matches this message, else false

Throws:

org.xmlBlaster.util.XmlBlasterException - Is thrown on problems, for example if the MIME type does not fit to message content.
Take care throwing an exception, the message is not updated and an error is logged and the message is sent as dead letter. (see TopicHandler.java:1032). It is best to return 'false' instead and handle the situation yourself.

shutdown

public void shutdown()

Description copied from interface: org.xmlBlaster.util.plugin.I_Plugin

Cleans up the resource.

Specified by:

shutdown in interface org.xmlBlaster.util.plugin.I_Plugin

toAlive

public void toAlive(org.xmlBlaster.util.dispatch.DispatchManager dispatchManager,
                    org.xmlBlaster.util.dispatch.ConnectionStateEnum oldState)

Specified by:

toAlive in interface org.xmlBlaster.util.dispatch.I_ConnectionStatusListener

toDead

public void toDead(org.xmlBlaster.util.dispatch.DispatchManager dispatchManager,
                   org.xmlBlaster.util.dispatch.ConnectionStateEnum oldState,
                   java.lang.String errorText)

Specified by:

toDead in interface org.xmlBlaster.util.dispatch.I_ConnectionStatusListener

toPolling

public void toPolling(org.xmlBlaster.util.dispatch.DispatchManager dispatchManager,
                      org.xmlBlaster.util.dispatch.ConnectionStateEnum oldState)

Specified by:

toPolling in interface org.xmlBlaster.util.dispatch.I_ConnectionStatusListener