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1
28 package net.sf.jasperreports.engine.data;
29
30 import java.util.Iterator  ;
31 import java.util.List ;
32
33 import net.sf.jasperreports.engine.JRRewindableDataSource;
34 import net.sf.jasperreports.engine.query.JRHibernateQueryExecuter;
35
36
45 public class JRHibernateListDataSource extends JRHibernateAbstractDataSource implements JRRewindableDataSource
46 {
47 private final int pageSize;
48 private int pageCount;
49 private boolean nextPage;
50 private List returnValues;
51 private Iterator iterator;
52
53 public JRHibernateListDataSource(JRHibernateQueryExecuter queryExecuter, boolean useFieldDescription, int pageSize)
54 {
55 super(queryExecuter, useFieldDescription, false);
56
57 this.pageSize = pageSize;
58
59 pageCount = 0;
60 fetchPage();
61 }
62
63 protected void fetchPage()
64 {
65 if (pageSize <= 0)
66 {
67 returnValues = queryExecuter.list();
68 nextPage = false;
69 }
70 else
71 {
72 returnValues = queryExecuter.list(pageCount * pageSize, pageSize);
73 nextPage = returnValues.size() == pageSize;
74 }
75
76 ++pageCount;
77
78 initIterator();
79 }
80
81 public boolean next()
82 {
83 if (iterator == null)
84 {
85 return false;
86 }
87
88 boolean hasNext = iterator.hasNext();
89 if (!hasNext && nextPage)
90 {
91 fetchPage();
92 hasNext = iterator != null && iterator.hasNext();
93 }
94
95 if (hasNext)
96 {
97 setCurrentRowValue(iterator.next());
98 }
99
100 return hasNext;
101 }
102
103 public void moveFirst()
104 {
105 if (pageCount == 1)
106 {
107 initIterator();
108 }
109 else
110 {
111 pageCount = 0;
112 fetchPage();
113 }
114 }
115
116 private void initIterator()
117 {
118 iterator = returnValues == null ? null : returnValues.iterator();
119 }
120 }
121 |
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