1 /**
2 * 2010, Digitalis Informatica. All rights reserved. Distribuicao e Gestao de Informatica, Lda. Estrada de Paco de Arcos
3 * num.9 - Piso -1 2780-666 Paco de Arcos Telefone: (351) 21 4408990 Fax: (351) 21 4408999 http://www.digitalis.pt
4 */
5
6 package pt.digitalis.dif.model.hibernate;
7
8 import java.util.Iterator;
9
10 import org.hibernate.Criteria;
11 import org.hibernate.ScrollableResults;
12
13 import pt.digitalis.utils.common.IBeanAttributes;
14
15 /**
16 * An {@link Iterator} for an Hibernate {@link ScrollableResults} result.<br>
17 * Will allow forward navigation with cache disabled, and entity cache cleanup at regular intervals to present Hibernate
18 * entity memory overflow in large result sets.
19 *
20 * @author Pedro Viegas <a href="mailto:pviegas@digitalis.pt">pviegas@digitalis.pt</a><br/>
21 * @param <T>
22 * the data type of the results
23 * @created 2010/10/01
24 */
25 public class HibernateScrollableResultsIterator<T extends IBeanAttributes> implements Iterator<T> {
26
27 // TODO: Review if this is necessary after implementation of this feature
28 // /** Iterator counter for hibernate memory flush */
29 // private long recordsServer = 0;
30
31 /** The result to iterate */
32 private ScrollableResults results;
33
34 /**
35 * Executes the given {@link Criteria} setting all necessary tweaks for simple non-cached forward navigation in the
36 * Result Set.
37 *
38 * @param criteria
39 */
40 public HibernateScrollableResultsIterator(Criteria criteria)
41 {
42 // TODO: Must Implement this
43 // this.results = results;
44 }
45
46 /**
47 * Wraps a {@link ScrollableResults} in an iterator implementation
48 *
49 * @param results
50 */
51 public HibernateScrollableResultsIterator(ScrollableResults results)
52 {
53 this.results = results;
54 }
55
56 /**
57 * @see java.util.Iterator#hasNext()
58 */
59 public boolean hasNext()
60 {
61
62 return results.next();
63 }
64
65 /**
66 * @see java.util.Iterator#next()
67 */
68 @SuppressWarnings("unchecked")
69 public T next()
70 {
71 return (T) results.get(0);
72 }
73
74 /**
75 * @see java.util.Iterator#remove()
76 */
77 public void remove()
78 {
79 throw new UnsupportedOperationException("remove() not supported");
80 }
81 }