jstrachan 02/05/24 05:02:29 Modified: jelly/xdocs index.xml Log: Restored previous home page that was changed to messenger's home page by accident! Whoops Revision Changes Path 1.4 +47 -341 jakarta-commons-sandbox/jelly/xdocs/index.xml Index: index.xml =================================================================== RCS file: /home/cvs/jakarta-commons-sandbox/jelly/xdocs/index.xml,v retrieving revision 1.3 retrieving revision 1.4 diff -u -r1.3 -r1.4 --- index.xml 23 May 2002 23:53:42 -0000 1.3 +++ index.xml 24 May 2002 12:02:29 -0000 1.4 @@ -1,341 +1,47 @@ -<?xml version="1.0"?> - -<document> - - <properties> - <title>Messenger</title> - <author email="[EMAIL PROTECTED]">James Strachan</author> - </properties> - -<body> - -<section name="Messenger : a web based JMS framework"> - -<p> - <ol> - - <li> - <a href="messenger.html#Introduction">Introduction</a> - </li> - - <li> - <a href="messenger.html#Documentation">Documentation</a> - </li> - - <li> - <a href="messenger.html#Example Config">Example Configuration</a> - </li> - - <li> - <a href="messenger.html#Example Code">Example Code</a> - </li> - - <li> - <a href="messenger.html#Configuration">Configuration</a> - </li> - - <li> - <a href="messenger.html#Messagelets">Messagelets</a> - </li> - </ol> -</p> - -</section> - -<section name="Introduction"> - -<p> -<b>Proposed by :</b> James Strachan -</p> - -<p> - <b>Messenger</b> is a JMS (Java Message Service) framework - which makes it very easy to use JMS in Web Service and Web Application environments. -</p> - -<p> - Messenger allows much of the complexity of the JMS API to be hidden behind - a simple facade API. -</p> - -<p> - In addition Messenger provides an XML deployment - configuration file to avoid having to litter your code with complex deployment - configuration details in your application code. -</p> - -<p> - Messenger also provides a Messagelet Engine which is a JMS based container - that can be deployed in any Servlet Engine to process JMS messages - via MessageListeners, Servlets or JSP. -</p> - -</section> - -<section name="Documentation"> - -<p> -The <a href="http://nagoya.apache.org/gump/javadoc/jakarta-commons-sandbox/messenger/dist/doc/api/index.html";>JavaDoc</a> -from the last nightly build is available online -or you can download a <a href="http://jakarta.apache.org/builds/jakarta-commons/nightly/commons-messenger/";>nightly build</a>. -</p> - -<p> -There is also the -<a href="http://cvs.apache.org/viewcvs/~checkout~/jakarta-commons-sandbox/messenger/STATUS.html";>status document</a>. -or the initial <a href="http://cvs.apache.org/viewcvs/~checkout~/jakarta-commons-sandbox/messenger/PROPOSAL.html";>proposal</a>. -</p> - -</section> - -<section name="Example Config"> - -<p> - Here is an example <i>Messenger.xml</i> deployment configuration file. -</p> - -<source><![CDATA[ -<?xml version="1.0" encoding="UTF-8"?> -<manager> - - <!-- this example Messenger XML config file should work with J2EE SDK --> - - <messenger name="topic"> - <jndi lookupName="TopicConnectionFactory"> - <property> - <name>com.sun.jms.internal.java.naming.factory.initial</name> - <value>com.sun.enterprise.naming.SerialInitContextFactory</value> - </property> - </jndi> - </messenger> - - <messenger name="queue"> - <jndi lookupName="QueueConnectionFactory"> - <property> - <name>com.sun.jms.internal.java.naming.factory.initial</name> - <value>com.sun.enterprise.naming.SerialInitContextFactory</value> - </property> - </jndi> - </messenger> - -</manager> -]]></source> - -<p> -It should work with the J2EE SDK to make 2 standard Messengers called -<i>topic</i> and <i>queue</i> respectively. -</p> - -<p> - So how would we use these 2 Messengers from Java code? -</p> - -</section> - -<section name="Example Code"> - -<p> -Here's some example code to send a message on a topic. -</p> - -<source><![CDATA[ - -// get a Messenger and Destination -Messenger messenger = MessengerManager.get( "topic" ); -Destination destination = messenger.getDestination( "CHAT.NEWBIES" ); - -// now lets send a message -TextMessage message = messenger.createTextMessage( "this is some text" ); -messenger.send( destination, message ); -]]></source> - -<p> -Here's some code to receive a message on a queue, blocking until the message arrives. -</p> - -<source><![CDATA[ - -// get a Messenger and Destination -Messenger messenger = MessengerManager.get( "queue" ); -Destination destination = messenger.getDestination( "REQUEST.BUILD" ); - -// now lets receive a message -Message message = messenger.receive( destination ); -]]></source> - - -<p> -Notice how the construction of individual Messenger objects can be hidden behind -the MessengerManager in a similar way to tools like <a href="http://jakarta.apache.org/log4j/docs/index.html";>log4j</a>. -</p> - -<p> -Also notice that the Messenger API is a simple facade, no need for Topic and Queue specific -coding as well as the use of MessageConsumer, MessageProducer, TopicPublisher, -TopicSubscriber, QueueSender, QueueReceiver and the plethora of Connection and Session objects. -</p> - - -</section> - - -<section name="Configuration"> - -<p> - By default, Messenger will look for an XML document called <i>Messenger.xml</i> - on the CLASSPATH as soon as a Messenger instance is looked up via the following code. -</p> - -<source><![CDATA[ - -Messenger messenger = MessengerManager.get( "customer.orders" ); -]]></source> - - -<p> - An alternative approach is to define the system property <i>org.apache.commons.messenger</i> - to point to a URL of a Messenger deployment configuration document. For example -</p> - -<source><![CDATA[ - - $ java -Dorg.apache.commons.messenger=http://localhost/config/Messenger.xml MyApplication -]]></source> - -<p> - In servlet environments its often a good idea to explicitly configure the - singleton <i>MessengerManager</i> - in a Servlet initialisation method using servlet initialisation parameters. - Here's an example -</p> - -<source><![CDATA[ - -public class MyServlet extends HttpServlet { - - public void init() throws ServletException { - // initialise the Messenger connections - String url = getInitParameter( "messenger" ); - if ( url != null ) { - MessengerManager.configure( url ); - } - } -} -]]></source> - -</section> - - -<section name="Messagelets"> - -<p> - The Messenger project provides a Messagelet Engine which is a JMS based Container which runs in any Servlet Engine - such as Tomcat 4.0. - The Messagelet Engine provides a simple framework for processing JMS messages in - a variety of ways using either regular JMS MessageListeners, Message Driven Objects, Servlets or even JSP. </p> - <p> In addition the Messagelet engine provides a Bridge mechanism which allows messages to be consumed from one destination and connection and sent to another destination, possibly using a different JMS connection and provider. This allows, for example, messages to be consumed on SpiritWave and sent to MQSeries, possibly applying some custom transformation along the way. </p> <p> The Bridge mechanism is provided via the <a href="messenger/api/org/apache/commons/messagelet/BridgeMDO.html">BridgeMDO</a> and using the <bridge> element inside a subscription deployment descriptor. </p> -<p> - To deploy a Messagelet Container you need to add the ManagerServlet in a web - application giving it an XML configuration file describing all the various JMS connections - and an XML configuration file describing all the subscriptions. -</p> -<p> - Here are example - <a href="http://cvs.apache.org/viewcvs/jakarta-commons-sandbox/messenger/src/conf/Messenger.xml?rev=1.3&content-type=text/vnd.viewcvs-markup";>connections</a> - and - <a href="http://cvs.apache.org/viewcvs/jakarta-commons-sandbox/messenger/src/webapp/conf/subscriptions.xml?rev=1.6&content-type=text/vnd.viewcvs-markup";>subscriptions</a> - XML configuration files. - There now follows the section you need to add to your web.xml configuration file to deploy the - Messagelet Manager Servlet. -</p> - -<source><![CDATA[ - - <servlet> - <servlet-name>managerServlet</servlet-name> - <servlet-class>org.apache.commons.messagelet.ManagerServlet</servlet-class> - <init-param> - <param-name>connections</param-name> - <param-value>/WEB-INF/Messenger.xml</param-value> - </init-param> - <init-param> - <param-name>subscriptions</param-name> - <param-value>/WEB-INF/subscriptions.xml</param-value> - </init-param> - <load-on-startup>1</load-on-startup> - </servlet> -]]></source> - -<p> - Once you've done the above and the web application is started the Messagelet engine will - subscribe to the various JMS subscriptions and then dispatch JMS messages to the various - MessageListener objects, Servlets or JSP pages. -</p> - -<p> - There are a variety of ways in which you can process JMS messages depending on your requirements. -</p> - -<ul> - -<li> - A MessageListener is a standard JMS listener of messages. -</li> - -<li> - A <a href="messenger/api/org/apache/commons/messagelet/MessageDrivenObject.html">MessageDrivenObject</a> is-a JMS MessageListener which has - extra servlet-based lifecycle methods just like a Servlet. - This allows - an MDO to know when its being initialised and when its being destroryed - and so do some resource management (such as creating or closing database - connections etc). Also on initialisation the MDO gets access to the - ServletContext so that it can read some initialization parameters from - the web application or perform web-app level logging and so on. -</li> - -<li> - A <a href="messenger/api/org/apache/commons/messagelet/MessengerMDO.html">MessengerMDO</a> is-a MessageDrivenObject - but also provides a number of helper methods such as access to the Messenger to - which its listening, so that responses can be sent back to the originator of the message, - as well as access to the ServletContext and some logging helper methods. -</li> - -<li> - A Servlet can be any GenericServlet or HttpServlet. - If the JMS message that is being dispatched is a TextMessage then the body of the message is - available via the ServletRequest.getReader() method, in the normal Servlet way. - Any output written to the ServletResponse.getWriter() will be converted into a TextMessage - and sent back to the originator. - All servlets and JSP pages have access to the originating JMS message and Messenger objects via - the "message" and "messenger" request attributes respectively. -</li> - -<li> - A <a href="messenger/api/org/apache/commons/messagelet/Messagelet.html">Messagelet</a> - is a JMS specific Servlet, just like a HttpServlet is a HTTP specific Servlet. It - provides access to a Messagelet specific - <a href="messenger/api/org/apache/commons/messagelet/MessageletRequest.html">MessageletRequest</a> - and - <a href="messenger/api/org/apache/commons/messagelet/MessageletResponse.html">MessageletResponse</a> - to allow access to the JMS Message and the Messenger for sending replies. -</li> - -<li> - A JSP page can be any piece of JSP, for example the standard JSP tag library can be used - to perform JavaScript, XPath, XSLT or SQL operations on the incoming message. - The request scope "message" and "messenger" attributes can be used to access the originating - JMS Message and Messenger objects. -</li> - -</ul> - -<p>There are some examples of an MDO, Servlet and Messagelet - <a href="http://cvs.apache.org/viewcvs/jakarta-commons-sandbox/messenger/src/webapp/src/";>here</a> or - you can see example JSP - <a href="http://cvs.apache.org/viewcvs/jakarta-commons-sandbox/messenger/src/webapp/web/jms/";>here</a> -</p> - -</section> - -</body> -</document> \ No newline at end of file +<?xml version="1.0"?> + +<document> + + <properties> + <title>Jelly : Java and XML based scripting engine</title> + <author email="[EMAIL PROTECTED]">James Strachan</author> + </properties> + +<body> + +<section name="Jelly : Java and XML based scripting engine"> + +<p> + <b>Jelly</b> +</p> + +<p><em>Jelly</em> is an XML based scripting and processing engine. Jelly borrows many +good ideas from both JSP custom tags, Velocity, Cocoon and the +scripting engine inside XDoclet. Jelly can be used from the command line, inside +Ant or inside a Servlet. +</p> + +<p> +Jelly is completely extendable via custom tags in a similar way to JSP. +Though Jelly is really simple and has no dependencies either Servlets or JSP. +</p> + +<p> +Jelly is based on an XML event pipeline architecture (SAX), like Cocoon, rather than being purely text +based like JSP and Velocity. This means that Jelly tags can consume XML events and emit them. Each +Jelly custom tag can then act as an XML source, result or transformation. +</p> + +<p>We hope Jelly can be both an XML processing and transformation engine, +a web and XML based scripting engine as well as a unit testing framework for +testing web applications and web services. +In addition Jelly can act as a stand alone lightweight engine for running JSTL +scripts which can be run from the command line, inside SOAP services or from Ant. +</p> + +</section> + + +</body> +</document> +
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