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1   /**
2   The contents of this file are subject to the Mozilla Public License Version 1.1 
3   (the "License"); you may not use this file except in compliance with the License. 
4   You may obtain a copy of the License at http://www.mozilla.org/MPL/ 
5   Software distributed under the License is distributed on an "AS IS" basis, 
6   WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the 
7   specific language governing rights and limitations under the License. 
8   
9   The Original Code is "DelegatingHiLoGenerator.java".  Description: 
10  "Generator that delegates generation of hi IDs " 
11  
12  The Initial Developer of the Original Code is University Health Network. Copyright (C) 
13  2001.  All Rights Reserved. 
14  
15  Contributor(s): ______________________________________. 
16  
17  Alternatively, the contents of this file may be used under the terms of the 
18  GNU General Public License (the  "GPL"), in which case the provisions of the GPL are 
19  applicable instead of those above.  If you wish to allow use of your version of this 
20  file only under the terms of the GPL and not to allow others to use your version 
21  of this file under the MPL, indicate your decision by deleting  the provisions above 
22  and replace  them with the notice and other provisions required by the GPL License.  
23  If you do not delete the provisions above, a recipient may use your version of 
24  this file under either the MPL or the GPL. 
25   */
26  package ca.uhn.hl7v2.util.idgenerator;
27  
28  import java.io.IOException;
29  
30  /**
31   * Default implementation of a HiLo ID generator that allows to use another
32   * (non-HiLo) ID generator for generating the "hi" part of the ID. The delegate
33   * must increment its ID is discrete steps > 1, so that the gaps can be filled
34   * with "lo" IDs.
35   * <p>
36   *     Example:
37   * </p>
38   * <pre>
39   *     Hi IDs: 0, 100, 200, 300 (increment = 100)
40   *     Lo IDs: 1,2,3,...,100,1,2,3,....
41   *     Resulting ID (Hi + Lo): 1,2,3,99,100,101,102,...
42   * </pre>
43   * 
44   * @see FileBasedHiLoGenerator
45   * @author Christian Ohr
46   */
47  public class DelegatingHiLoGenerator extends HiLoGenerator {
48  
49  	private IDGenerator.Ordered delegate;
50  
51  	public DelegatingHiLoGenerator() {
52  		super();
53  	}
54  
55  	public DelegatingHiLoGenerator(IDGenerator.Ordered delegate) {
56  		super();
57  		this.delegate = delegate;
58  	}
59  
60  	@Override
61  	protected long getNextHiId() throws IOException {
62  		if (delegate == null)
63  			throw new NullPointerException(
64  					"Must initialize delegate IDGenerator");
65  		return Long.parseLong(delegate.getID());
66  	}
67  
68  	public void setDelegate(IDGenerator.Ordered delegate) {
69  		this.delegate = delegate;
70  	}
71  
72  	@Override
73  	protected void resetHiId() {
74  		delegate.reset();
75  	}
76  
77      /**
78       * THe maximum "lo" ID is the increment of the hi ID.
79       * @return
80       */
81  	@Override
82  	public long getMaxLo() {
83  		return delegate.getIncrement();
84  	}
85  
86  }