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 "MLLPTransport.java". Description:
010 "An implementation of the HL7 Minimal Lower Layer Protocol."
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.io.IOException;
030 import java.io.InputStream;
031 import java.util.Properties;
032
033 import ca.uhn.hl7v2.llp.LLPException;
034 import ca.uhn.hl7v2.llp.MinLLPReader;
035 import ca.uhn.hl7v2.llp.MinLLPWriter;
036 import ca.uhn.hl7v2.protocol.StreamSource;
037 import ca.uhn.hl7v2.protocol.TransportException;
038 import ca.uhn.hl7v2.protocol.TransportLayer;
039 import ca.uhn.hl7v2.protocol.Transportable;
040
041 /**
042 * An implementation of the HL7 Minimal Lower Layer Protocol (see
043 * HL7 implementation guide appendix C). Note that this is the most common
044 * protocol used in HL7 interfaces.
045 *
046 * @author <a href="mailto:bryan.tripp@uhn.on.ca">Bryan Tripp</a>
047 * @version $Revision: 1.1 $ updated on $Date: 2007-02-19 02:24:26 $ by $Author: jamesagnew $
048 */
049 public class MLLPTransport extends AbstractTransport implements TransportLayer {
050
051 private MinLLPReader myReader;
052 private MinLLPWriter myWriter;
053
054 private StreamSource myStreamSource;
055 private Properties myCharsetMappings;
056
057 /**
058 * @param theStreamSource the provider of input and output streams connected
059 * to the remote server
060 */
061 public MLLPTransport(StreamSource theStreamSource) throws TransportException {
062 myStreamSource = theStreamSource;
063 myCharsetMappings = loadCharsetMappings();
064 }
065
066 private static Properties loadCharsetMappings() throws TransportException {
067 Properties mappings = new Properties();
068 String resource = "ca/uhn/hl7v2/protocol/impl/charset_map.properties";
069 InputStream in = MLLPTransport.class.getClassLoader().getResourceAsStream(resource);
070 try {
071 mappings.load(in);
072 } catch (IOException e) {
073 throw new TransportException("Can't load character set mappings from " + resource, e);
074 }
075 return mappings;
076 }
077
078 /**
079 * @see ca.uhn.hl7v2.protocol.AstractTransport#doSend(ca.uhn.hl7v2.protocol.Transportable)
080 */
081 public void doSend(Transportable theMessage) throws TransportException {
082 try {
083 String charset = (String) theMessage.getMetadata().get("MSH-18");
084 if (charset != null) {
085 charset = myCharsetMappings.getProperty(charset, charset); //default to self if no match
086 myWriter.writeMessage(theMessage.getMessage(), charset);
087 } else {
088 myWriter.writeMessage(theMessage.getMessage());
089 }
090 } catch (LLPException e) {
091 throw new TransportException(e);
092 } catch (IOException e) {
093 throw new TransportException(e);
094 }
095 }
096
097 /**
098 * @see ca.uhn.hl7v2.protocol.impl.AbstractTransport#doReceive()
099 */
100 public Transportable doReceive() throws TransportException {
101 Transportable result = null;
102 try {
103 String message = myReader.getMessage();
104 if (message != null) {
105 result = new TransportableImpl(message);
106 }
107 } catch (LLPException e) {
108 throw new TransportException(e);
109 } catch (IOException e) {
110 throw new TransportException(e);
111 }
112 return result;
113 }
114
115 /**
116 * @see ca.uhn.hl7v2.protocol.AbstractTransport#doConnect()
117 */
118 public void doConnect() throws TransportException {
119 myStreamSource.connect();
120 try {
121 myReader = new MinLLPReader(myStreamSource.getInboundStream());
122 myWriter = new MinLLPWriter(myStreamSource.getOutboundStream());
123 } catch (IOException e) {
124 throw new TransportException(e);
125 }
126 }
127
128 /**
129 * @see ca.uhn.hl7v2.protocol.TransportLayer#disconnect()
130 */
131 public void doDisconnect() throws TransportException {
132 try {
133 if (myReader != null) myReader.close();
134 if (myWriter != null) myWriter.close();
135 } catch (IOException e) {
136 throw new TransportException(e);
137 } finally {
138 myReader = null;
139 myWriter = null;
140 }
141 myStreamSource.disconnect();
142 }
143
144 }