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 "Receiver.java". Description:
010 * "Listens for incoming messages on a certain input stream, and
011 * sends them to the appropriate location."
012 *
013 * The Initial Developer of the Original Code is University Health Network. Copyright (C)
014 * 2002. All Rights Reserved.
015 *
016 * Contributor(s): _____________.
017 *
018 * Alternatively, the contents of this file may be used under the terms of the
019 * GNU General Public License (the "GPL"), in which case the provisions of the GPL are
020 * applicable instead of those above. If you wish to allow use of your version of this
021 * file only under the terms of the GPL and not to allow others to use your version
022 * of this file under the MPL, indicate your decision by deleting the provisions above
023 * and replace them with the notice and other provisions required by the GPL License.
024 * If you do not delete the provisions above, a recipient may use your version of
025 * this file under either the MPL or the GPL.
026 */
027
028 package ca.uhn.hl7v2.app;
029
030 import java.io.IOException;
031 import java.net.SocketException;
032
033 import org.slf4j.Logger;
034 import org.slf4j.LoggerFactory;
035
036 import ca.uhn.hl7v2.concurrent.Service;
037 import ca.uhn.hl7v2.llp.HL7Reader;
038
039 /**
040 * Listens for incoming messages on a certain input stream, and sends them to
041 * the appropriate location.
042 *
043 * @author Bryan Tripp
044 */
045 public class Receiver extends Service {
046
047 private static final Logger log = LoggerFactory.getLogger(Receiver.class);
048
049 private Connection conn;
050 private HL7Reader in;
051
052 /** Creates a new instance of Receiver, associated with the given Connection */
053 public Receiver(Connection c, HL7Reader in) {
054 super("Receiver", c.getExecutorService());
055 this.conn = c;
056 this.in = in;
057 }
058
059
060 @Override
061 protected void handle() {
062 try {
063 String message = in.getMessage();
064 if (message == null) {
065 log.debug("Failed to read a message");
066 } else {
067 processMessage(message);
068 }
069 } catch (SocketException e) {
070 // This probably means that the client closed the server connection normally
071 conn.close();
072 log.info("SocketException: closing Connection, will no longer read messages with this Receiver: " + e.getMessage());
073 } catch (IOException e) {
074 conn.close();
075 log.warn("IOException: closing Connection, will no longer read messages with this Receiver. ", e);
076 } catch (Exception e) {
077 log.error("Error while closing connection: ", e);
078 }
079
080 }
081
082
083 /**
084 * Processes a single incoming message by sending it to the appropriate
085 * internal location. If an incoming message contains an MSA-2 field, it is
086 * assumed that this message is meant as a reply to a message that has been
087 * sent earlier. In this case an attempt is give the message to the object
088 * that sent the corresponding outbound message. If the message contains an
089 * MSA-2 but there are no objects that appear to be waiting for it, it is
090 * discarded and an exception is logged. If the message does not contain an
091 * MSA-2 field, it is concluded that the message has arrived unsolicited. In
092 * this case it is sent to the Responder (in a new Thread).
093 */
094 protected void processMessage(String message) {
095 String ackID = conn.getParser().getAckID(message);
096 if (ackID == null) {
097 log.debug("Unsolicited Message Received: {}", message);
098 getExecutorService().submit(new Grunt(conn, message));
099 } else {
100 if (!conn.isRecipientWaiting(ackID, message)) {
101 log.info("Unexpected Message Received: {}", message);
102 } else {
103 log.debug("Response Message Received: {}", message);
104 }
105 }
106 }
107
108 /** Independent thread for processing a single message */
109 private class Grunt implements Runnable {
110
111 private Connection conn;
112 private String m;
113
114 public Grunt(Connection conn, String message) {
115 this.conn = conn;
116 this.m = message;
117 }
118
119 public void run() {
120 try {
121 String response = conn.getResponder().processMessage(m);
122 conn.getAckWriter().writeMessage(response);
123 } catch (Exception e) {
124 log.error("Error while processing message: ", e);
125 }
126 }
127 }
128
129 }