|
1
28 package net.sf.jasperreports.engine.data;
29
30 import java.util.HashMap  ;
31 import java.util.Iterator ;
32 import java.util.List ;
33 import java.util.Map ;
34
35 import net.sf.jasperreports.engine.JRException;
36 import net.sf.jasperreports.engine.JRField;
37 import net.sf.jasperreports.engine.JRRewindableDataSource;
38 import net.sf.jasperreports.engine.JRRuntimeException;
39 import net.sf.jasperreports.engine.query.JRJpaQueryExecuter;
40
41
60 public class JRJpaDataSource extends JRAbstractBeanDataSource implements JRRewindableDataSource {
61 private static final String MAPPING_INDEX_PREFIX = "COLUMN_";
62 private static final int MAPPING_INDEX_PREFIX_LENGTH = MAPPING_INDEX_PREFIX.length();
63 private static final String MAPPING_INDEX_PROPERTY_SEP = ".";
64 private static final int MAPPING_INDEX_PROPERTY_SEP_LENGTH = MAPPING_INDEX_PROPERTY_SEP.length();
65
66 private final JRJpaQueryExecuter queryExecuter;
67 private final int pageSize;
68 private int pageCount;
69 private boolean nextPage;
70 private List returnValues;
71 private Iterator iterator;
72 protected Object currentRow;
73 private Map fieldValueReaders;
74
75 public JRJpaDataSource(JRJpaQueryExecuter queryExecuter, int pageSize) {
76 super(true);
77
78 this.queryExecuter = queryExecuter;
79 this.pageSize = pageSize;
80
81 fieldValueReaders = new HashMap ();
82
83 pageCount = 0;
84 fetchPage();
85 }
86
87 protected void fetchPage() {
88 if (pageSize <= 0) {
89 returnValues = queryExecuter.getResultList();
90 nextPage = false;
91 }
92 else {
93 returnValues = queryExecuter.getResultList(pageCount * pageSize, pageSize);
94 nextPage = returnValues.size() == pageSize;
95 }
96
97 ++pageCount;
98
99 initIterator();
100 }
101
102 public boolean next() {
103 if (iterator == null) {
104 return false;
105 }
106
107 boolean hasNext = iterator.hasNext();
108 if (!hasNext && nextPage) {
109 fetchPage();
110 hasNext = iterator != null && iterator.hasNext();
111 }
112
113 if (hasNext) {
114 currentRow = iterator.next();
115 }
116
117 return hasNext;
118 }
119
120 public void moveFirst() {
121 if (pageCount == 1) {
122 initIterator();
123 }
124 else {
125 pageCount = 0;
126 fetchPage();
127 }
128 }
129
130 private void initIterator() {
131 iterator = returnValues == null ? null : returnValues.iterator();
132 }
133
134 public Object getFieldValue(JRField field) throws JRException {
135 FieldValueReader reader = getFieldValueReader(field);
136 return reader.getValue();
137 }
138
139 protected FieldValueReader getFieldValueReader(JRField field)
140 {
141 FieldValueReader reader = (FieldValueReader) fieldValueReaders.get(field.getName());
142 if (reader == null)
143 {
144 String mapping = getPropertyName(field);
145 reader = createReader(mapping);
146 fieldValueReaders.put(field.getName(), reader);
147 }
148 return reader;
149 }
150
151 private FieldValueReader createReader(String mapping)
152 {
153 FieldValueReader reader = null;
154 if (mapping.startsWith(MAPPING_INDEX_PREFIX))
155 {
156 int propertySepIdx = mapping.indexOf(MAPPING_INDEX_PROPERTY_SEP, MAPPING_INDEX_PREFIX_LENGTH + 1);
157 if (propertySepIdx < 0)
158 {
159 String indexStr = mapping.substring(MAPPING_INDEX_PREFIX_LENGTH);
160 try
161 {
162 int index = Integer.parseInt(indexStr);
163 reader = new IndexReader(index - 1);
164 }
165 catch (NumberFormatException e)
166 {
167 }
169 }
170 else
171 {
172 String indexStr = mapping.substring(MAPPING_INDEX_PREFIX_LENGTH, propertySepIdx);
173 try
174 {
175 int index = Integer.parseInt(indexStr);
176 String property = mapping.substring(propertySepIdx + MAPPING_INDEX_PROPERTY_SEP_LENGTH);
177 reader = new IndexPropertyReader(index - 1, property);
178 }
179 catch (NumberFormatException e)
180 {
181 }
183 }
184 }
185
186 if (reader == null)
188 {
189 reader = new PropertyReader(mapping);
190 }
191
192 return reader;
193 }
194
195 protected static interface FieldValueReader
196 {
197 Object getValue() throws JRException;
198 }
199
200 protected class PropertyReader implements FieldValueReader
201 {
202 private final String property;
203
204 public PropertyReader(String property)
205 {
206 this.property = property;
207 }
208
209 public Object getValue() throws JRException
210 {
211 return getBeanProperty(currentRow, property);
212 }
213 }
214
215 protected class IndexReader implements FieldValueReader
216 {
217 private final int position;
218
219 public IndexReader(int position)
220 {
221 this.position = position;
222 }
223
224 public Object getValue() throws JRException
225 {
226 Object [] values = (Object []) currentRow;
227 if (position < 0 || position >= values.length)
228 {
229 throw new JRRuntimeException("Index " + position + " out of bounds for query result of lenght " + values.length);
230 }
231 return values[position];
232 }
233 }
234
235 protected class IndexPropertyReader implements FieldValueReader
236 {
237 private final int position;
238 private final String property;
239
240 public IndexPropertyReader(int position, String property)
241 {
242 this.position = position;
243 this.property = property;
244 }
245
246 public Object getValue() throws JRException
247 {
248 Object [] values = (Object []) currentRow;
249 if (position < 0 || position >= values.length)
250 {
251 throw new JRRuntimeException("Index " + position + " out of bounds for query result of lenght " + values.length);
252 }
253 return getBeanProperty(values[position], property);
254 }
255 }
256 }
257 |
Popular Tags |
Java API By Example, From Geeks To Geeks.