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 "ValidationContextFactory.java". Description: 010 "Source of ValidationContext" 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 package ca.uhn.hl7v2.validation.impl; 027 028 import ca.uhn.hl7v2.validation.ValidationContext; 029 import ca.uhn.hl7v2.validation.ValidationException; 030 031 /** 032 * <p>Source of <code>ValidationContext</code>. </p> 033 * 034 * <p>The <code>ValidationContext</code> returned by <code>getContext()</code> 035 * is determined by the system property "ca.uhn.hl7v2.validation.context_class". 036 * This factory defines two inner classes that can be used: DefaultValidation 037 * and NoValidation. You can also create your own context, setting whatever rules 038 * you want in its constructor, and reference it instead (it must have a zero-arg 039 * constructor). If this property is not set, DefaultValidation is used. </p> 040 * 041 * <p>Also note that the contexts provided here extend <code>ValidationContextImpl</code>, 042 * so rule bindings can be added or removed programmatically from the starting set. </p> 043 * 044 * @author <a href="mailto:bryan.tripp@uhn.on.ca">Bryan Tripp</a> 045 * @version $Revision: 1.1 $ updated on $Date: 2007/02/19 02:24:40 $ by $Author: jamesagnew $ 046 */ 047 public class ValidationContextFactory { 048 049 private static ValidationContext ourContext; 050 public static final String CONTEXT_PROPERTY = "ca.uhn.hl7v2.validation.context_class"; 051 052 /** 053 * Returns a singleton <code>ValidationContext</code>, creating it if necessary. 054 * 055 * @return <code>ValidationContext</code> 056 */ 057 public synchronized static ValidationContext getContext() throws ValidationException { 058 if (ourContext == null) { 059 String contextClassName = System.getProperty(CONTEXT_PROPERTY); 060 if (contextClassName == null) { 061 ourContext = new DefaultValidation(); 062 } else { 063 Class c; 064 try { 065 c = Class.forName(contextClassName); 066 ourContext = (ValidationContext) c.newInstance(); 067 } catch (Exception e) { 068 throw new ValidationException(e); 069 } 070 } 071 } 072 return ourContext; 073 } 074 075 }