001    /*
002     * Created on 16-Apr-2004
003     */
004    package ca.uhn.hl7v2.protocol;
005    
006    import ca.uhn.hl7v2.HL7Exception;
007    
008    /**
009     * Represents a persistent store for incoming messages.  Messages 
010     * may be stored here before an accept ACK is returned.  The local
011     * side of the interface then takes on responsibility for delivering 
012     * the message to the application.  
013     * 
014     * @author <a href="mailto:bryan.tripp@uhn.on.ca">Bryan Tripp</a>
015     * @version $Revision: 1.1 $ updated on $Date: 2007-02-19 02:24:38 $ by $Author: jamesagnew $
016     */
017    public interface SafeStorage {
018    
019        /**
020         * Stores a message so that it can be reliably retrieved and sent to 
021         * the proper application, even if this service is restarted in the mean
022         * time.
023         *  
024         * @param theMessage the message to store 
025         * @throws HL7Exception if there is some problem accessing the store
026         */
027        public void store(Transportable theMessage) throws HL7Exception;
028        
029        /**
030         * If the given message exists in the store, it is removed.
031         *   
032         * @param theMessage the message to discard
033         * @throws HL7Exception if there is some problem accessing the store
034         */
035        public void discard(Transportable theMessage) throws HL7Exception;
036        
037        /**
038         * Returns all messages that have been stored.  The store retains a copy 
039         * of each one until discard() is called.  This method would be called 
040         * after the HL7 server is restarted.
041         *      
042         * @return all messages in the store 
043         * @throws HL7Exception if there is some problem accessing the store
044         */
045        public Transportable[] restore() throws HL7Exception;
046        
047    }