Technotrance, Illusions and Perspectives

There are 7 types of contexts available in JBoss Seam. In order to outject (make an instantiated/ populated object available to other components participating in the same context) for a particular scope, say CONVERSATION, there are at least 2 ways of outjecting an instance as follows:

1) Declaratively : This could be used when there are component boundaries clearly demarcated and the instance needs to available for a longer running conversation. An example snippet is given below:

@Name("producer")
public class Producer
{   @Out(scope=ScopeType.CONVERSATION)
      private QueueFeed feed;

      //methods to produce and populate the feed
      @Begin public void doStart(){}
      @End public void close(){}
}

@Name("consumer")
public class Consumer
{   @In  private QueueFeed feed;
       //methods to consume and cleanup the feed
}

2) Programmaticaly : This approach is used when one would want place the instance in the already established context, and other seam components just reference the instance and used as given below:

@Name("producer")
public class Producer
{   public void produceIntermediate()
    {   QueueFeed queueFeed;
         //populate queueFeed
        Contexts.getConversationContext().set("queueFeed", queueFeed);
     }
}

@Name("consumer")
public class Consumer
{  public void consumeIntermediate()
    {   QueueFeed queueFeed = (QueueFeed) ( Contexts.getConversationContext().get("queueFeed",));
     }
}

This way one can manage scopes effectively with regard to instance usage across participating components