A MessageDriven Bean Example FTP App'

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A Message-Driven Bean Example FTP App.

• Peng-sheng,chen

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Example Application Overview

• This application has the following components
• FtpMessageClient A J2EE application client that
  sends file object messages to a queue.
• FtpMessageBean A message-driven bean that
  asynchronously receives and processes the file
  object messages that are sent to the queue.

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The J2EE Application Client

• queueConnectionFactory (QueueConnectionFactory)
  jndiContext.lookup ("javacomp/env/jms/MyQueueConn
  ectionFactory")
• queue (Queue) jndiContext.lookup("javacomp/env/
  jms/QueueName")

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The Message-Driven Bean Class

• The Message DrivenBean and Message Listener
  interfaces.
• The onMessage method.
• It implements one ejbCreate method and one
  ejbRemove method.
• It contains a public constructor with no
  arguments.
• It must not define the finalize method.

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The onMessage Method

• When the queue receives a message, the EJB
  container invokes the onMessage method of the
  message-driven bean.
• In the FtpMessageBean class, the onMessage
  method casts the incoming file to a FileMessage
  and displays the file successful sending message.

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The ejbCreate and ejbRemove Methods

• The access control modifier must be public.
• The return type must be void.
• The modifier cannot be static or final.
• The throws clause must not define any application
  exceptions.
• The method has no arguments

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JAVA File I/O
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Modify Security file

• Locate at j2sdkee1.3.1\lib\security
• Modify server.policy
• Type grant permissionjava.security.AllPermission
  

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JNDI Names  
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