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 "LowerLayerProtocol.java". Description: 010 "Represents a particular "lower layer protocol" over which HL7 messages can be 011 sent" 012 013 The Initial Developer of the Original Code is University Health Network. Copyright (C) 014 2001. 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 */ 028 029 package ca.uhn.hl7v2.llp; 030 031 import java.io.InputStream; 032 import java.io.OutputStream; 033 034 import ca.uhn.log.HapiLog; 035 import ca.uhn.log.HapiLogFactory; 036 037 /** 038 * Represents a particular "lower layer protocol" over which HL7 messages can be 039 * sent. An example is the "minimal lower layer protocol" defines in the HL7 040 * implementation guide (appendix C) - this is implemented by the class 041 * MinLowerLayerProtocol. Implementations should call the static method 042 * <code>logCharacterReceived()</code> when a character is read from a remote system. 043 * This method may or may not log receipt, as configured (see docs for this method). 044 * @author Bryan Tripp 045 */ 046 public abstract class LowerLayerProtocol { 047 048 private static final HapiLog log = HapiLogFactory.getHapiLog(LowerLayerProtocol.class); 049 private static boolean logChars = false; 050 051 /** 052 * Creates a new LowerLayerProtocol. 053 */ 054 protected LowerLayerProtocol() { 055 String logCharsProp = System.getProperty("ca.uhn.hl7v2.llp.logBytesRead"); 056 if (logCharsProp != null && logCharsProp.equalsIgnoreCase("TRUE")) { 057 log.info("Setting ca.uhn.hl7v2.llp.logBytesRead to TRUE"); 058 logChars = true; 059 } 060 } 061 062 /** 063 * Returns a particular implementation of LowerLayerProtocol. Currently 064 * MinLowerLayerProtocol is the default and there are no other options ... 065 * the idea is that this will eventually be configurable. 066 */ 067 public static LowerLayerProtocol makeLLP() { 068 return new MinLowerLayerProtocol(); 069 } 070 071 /** 072 * Returns an HL7Reader that implements message reading according to 073 * this protocol. 074 */ 075 public abstract HL7Reader getReader(InputStream in) throws LLPException; 076 077 /** 078 * Returns an HL7Writer that implements message writing according to 079 * this protocol. 080 */ 081 public abstract HL7Writer getWriter(OutputStream out) throws LLPException; 082 083 /** 084 * Logs the fact that a character has been received, if configured to do so. This is a 085 * debuging feature. This is enabled by setting the system property 086 * ca.uhn.hl7v2.llp.logBytesRead=TRUE (before LowerLayerProtocol is instantiated). 087 * A message is written to standard out for each character. THIS IS VERY SLOW and should 088 * normally be turned off. 089 */ 090 public static void logCharacterReceived(int c) { 091 if (logChars) { 092 System.out.println("Char received: " + c + " (" + (char) c + ")"); 093 } 094 } 095 096 }