001 /*
002 The contents of this file are subject to the Mozilla Public License Version 1.1
003 (the "License"); you may not use this file except in compliance with the License.
004 You may obtain a copy of the License at http://www.mozilla.org/MPL/
005 Software distributed under the License is distributed on an "AS IS" basis,
006 WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the
007 specific language governing rights and limitations under the License.
008
009 The Original Code is "AbstactTransport.java". Description:
010 "A base implementation of TransportLayer."
011
012 The Initial Developer of the Original Code is University Health Network. Copyright (C)
013 2004. All Rights Reserved.
014
015 Contributor(s): ______________________________________.
016
017 Alternatively, the contents of this file may be used under the terms of the
018 GNU General Public License (the "GPL"), in which case the provisions of the GPL are
019 applicable instead of those above. If you wish to allow use of your version of this
020 file only under the terms of the GPL and not to allow others to use your version
021 of this file under the MPL, indicate your decision by deleting the provisions above
022 and replace them with the notice and other provisions required by the GPL License.
023 If you do not delete the provisions above, a recipient may use your version of
024 this file under either the MPL or the GPL.
025 */
026
027 package ca.uhn.hl7v2.protocol.impl;
028
029 import java.util.HashMap;
030 import java.util.Map;
031
032 import org.slf4j.Logger;
033 import org.slf4j.LoggerFactory;
034
035 import ca.uhn.hl7v2.protocol.TransportException;
036 import ca.uhn.hl7v2.protocol.TransportLayer;
037 import ca.uhn.hl7v2.protocol.Transportable;
038
039 /**
040 * A base implementation of <code>TransportLayer</code> which looks after the
041 * addition of common metadata to each inbound <code>Transportable</code>.
042 *
043 * @author <a href="mailto:bryan.tripp@uhn.on.ca">Bryan Tripp</a>
044 * @version $Revision: 1.1 $ updated on $Date: 2007-02-19 02:24:26 $ by $Author: jamesagnew $
045 */
046 public abstract class AbstractTransport implements TransportLayer {
047
048 private static Logger log = LoggerFactory.getLogger(AbstractTransport.class);
049
050 private Map<String, Object> myCommonMetadata;
051 private boolean myIsConnected = false;
052
053 public AbstractTransport() {
054 myCommonMetadata = new HashMap<String, Object>();
055 }
056
057 /**
058 * @see ca.uhn.hl7v2.protocol.TransportLayer#getCommonMetadata()
059 */
060 public Map<String, Object> getCommonMetadata() {
061 return myCommonMetadata;
062 }
063
064 /**
065 * Delegates to <code>doReceive()</code> and adds common metadata
066 * to the resulting <code>Transportable</code> before it is returned.
067 */
068 public Transportable receive() throws TransportException {
069 if (!isConnected()) {
070 throw new TransportException("Can't receive because TransportLayer is not connected");
071 }
072
073 Transportable message = doReceive();
074 if (message != null) {
075 message.getMetadata().putAll(myCommonMetadata);
076 }
077
078 log.info("Received: {} ", (message == null ? null : message.getMessage()));
079
080 return message;
081 }
082
083 /**
084 * Called by receive(), which then adds common metadata.
085 *
086 * @return Transportable the next available message
087 * @throws TransportException
088 */
089 public abstract Transportable doReceive() throws TransportException;
090
091 /**
092 * Delegates to <code>doSend()</code> after checking that we are connected.
093 *
094 * @see ca.uhn.hl7v2.protocol.TransportLayer#send(Transportable)
095 */
096 public void send(Transportable theMessage) throws TransportException {
097 if (!isConnected()) {
098 throw new TransportException("Can't send because TransportLayer is not connected");
099 }
100
101 doSend(theMessage);
102
103 log.info("Sent: {}", (theMessage == null ? null : theMessage.getMessage()));
104 }
105
106 /**
107 * The method send() delegates to this method after checking whether we are
108 * connected.
109 * @param theMessage
110 * @throws TransportException
111 */
112 public abstract void doSend(Transportable theMessage) throws TransportException;
113
114 /**
115 * Sets isConnected() to false, then calls doConnect(), then sets isConnected() to
116 * true.
117 * @see ca.uhn.hl7v2.protocol.TransportLayer#connect()
118 */
119 public void connect() throws TransportException {
120 myIsConnected = false;
121 doConnect();
122 myIsConnected = true;
123 }
124
125 /**
126 * Performs connection as described in TransportLayer.connect(). The
127 * connect() method of this class delegates to doConnect() after some
128 * internal housekeeping.
129 *
130 * @throws TransportException
131 */
132 public abstract void doConnect() throws TransportException;
133
134 /**
135 * @see ca.uhn.hl7v2.protocol.TransportLayer#isConnected()
136 */
137 public boolean isConnected() {
138 return myIsConnected;
139 }
140
141 /**
142 * @see ca.uhn.hl7v2.protocol.TransportLayer#disconnect()
143 */
144 public void disconnect() throws TransportException {
145 myIsConnected = false;
146 doDisconnect();
147 }
148
149 /**
150 * Performs disconnection as described in TransportLayer.disconnect(). The
151 * disconnect() method of this class delegates to doDisconnect() after some
152 * internal housekeeping.
153 *
154 * @throws TransportException
155 */
156 public abstract void doDisconnect() throws TransportException;
157
158 }