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1
2
12 package com.versant.core.ejb;
13
14 import com.versant.core.server.CompiledQuery;
15 import com.versant.core.server.QueryResultWrapper;
16 import com.versant.core.common.QueryResultContainer;
17 import com.versant.core.common.BindingSupportImpl;
18 import com.versant.core.jdo.JDOListIterator;
19 import com.versant.core.jdo.QueryResultBase;
20
21 import java.util.NoSuchElementException  ;
22
23
26 public class EJBQueryIterator implements JDOListIterator {
27 private EMProxy pm;
28
29 private Object [] data;
30 private int actualSize;
31 private int indexInData;
32 private QueryResultWrapper qrw;
33 private boolean noMoreDataInResultSet;
34 private boolean closed;
35 private int nextIndex;
36
37 public EJBQueryIterator(EMProxy pm, CompiledQuery compiledQuery, Object [] params,
38 boolean doNotFlush) {
39 this.pm = pm;
40 if (!doNotFlush && !compiledQuery.getQueryDetails().isIgnoreCache()) {
41 pm.flushIfDepOn(compiledQuery.getEvictionClassBits());
42 }
43 qrw = pm.executeQuery(compiledQuery, params);
44 }
45
46 public void remove() {
47 throw BindingSupportImpl.getInstance().unsupported("Not allowed to modify");
48 }
49
50 public boolean hasNext() {
51 if (closed) return false;
52
53 if (!noMoreDataInResultSet && (data == null || indexInData == actualSize)) {
54 getMoreData();
55 }
56 return !(data == null || indexInData == actualSize);
57 }
58
59
66 public Object next() {
67 if (closed) {
68 throw new NoSuchElementException ();
69 }
70
71 if (!noMoreDataInResultSet && (data == null || indexInData == actualSize)) {
72 getMoreData();
73 }
74 return getNextData();
75 }
76
77 private void getMoreData() {
78 QueryResultContainer container = pm.getNextQueryResult(qrw, 0);
80 pm.addToCache(container.container);
81
82 data = container.getDataArray();
83 actualSize = container.size();
84 noMoreDataInResultSet = container.isqFinished();
85 indexInData = 0;
86 }
87
88 private Object getNextData() {
89 if (indexInData == actualSize) throw new NoSuchElementException ();
90 nextIndex++;
91 return QueryResultBase.resolveRow(data[indexInData++], pm);
92 }
93
94
97 public void close() {
98 if (closed) return;
99
100 if (qrw != null) {
101 pm.closeQuery(qrw);
102 qrw = null;
103 }
104
105 pm = null;
106 data = null;
107 qrw = null;
108
109 closed = true;
110 }
111
112 public int nextIndex() {
113 return nextIndex;
114 }
115
116 public int previousIndex() {
117 return nextIndex - 1;
118 }
119
120 public boolean hasPrevious() {
121 return nextIndex != 0;
122 }
123
124 public Object previous() {
125 throw BindingSupportImpl.getInstance().unsupportedOperation(null);
126 }
127
128 public void add(Object o) {
129 throw BindingSupportImpl.getInstance().unsupported("Not allowed to modify");
130 }
131
132 public void set(Object o) {
133 throw BindingSupportImpl.getInstance().unsupported("Not allowed to modify");
134 }
135 }
136
137
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