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12 package com.versant.core.jdbc.sql;
13
14 import com.versant.core.metadata.MDStatics;
15 import com.versant.core.jdbc.JdbcKeyGenerator;
16 import com.versant.core.jdbc.JdbcKeyGeneratorFactory;
17 import com.versant.core.jdbc.JdbcMetaDataBuilder;
18 import com.versant.core.jdbc.metadata.JdbcColumn;
19 import com.versant.core.jdbc.metadata.JdbcTable;
20 import com.versant.core.jdbc.metadata.JdbcMappingResolver;
21
22 import java.sql.*;
23 import java.util.HashSet  ;
24 import java.util.Iterator ;
25
26 import com.versant.core.common.BindingSupportImpl;
27
28
32 public class HighLowJdbcKeyGenerator implements JdbcKeyGenerator {
33
34
37 public static class Args {
38
39
40 private String tableName = "jdo_keygen";
41
42
43 private String keyColumnName = "table_name";
44 private String valueColumnName = "last_used_id";
45 private int keyColumnLength = 64;
46 private int grabSize = 10;
47 private int start;
48 private boolean createTable = true;
49 private String pkConstraint;
50
51 public Args() {
52 }
53
54 public String getTableName() {
55 return tableName;
56 }
57
58 public void setTableName(String tableName) {
59 this.tableName = tableName;
60 }
61
62 public String getKeyColumnName() {
63 return keyColumnName;
64 }
65
66 public void setKeyColumnName(String keyColumnName) {
67 this.keyColumnName = keyColumnName;
68 }
69
70 public String getValueColumnName() {
71 return valueColumnName;
72 }
73
74 public void setValueColumnName(String valueColumnName) {
75 this.valueColumnName = valueColumnName;
76 }
77
78 public int getKeyColumnLength() {
79 return keyColumnLength;
80 }
81
82 public void setKeyColumnLength(int keyColumnLength) {
83 this.keyColumnLength = keyColumnLength;
84 }
85
86 public int getGrabSize() {
87 return grabSize;
88 }
89
90 public void setGrabSize(int grabSize) {
91 this.grabSize = grabSize;
92 }
93
94 public int getStart() {
95 return start;
96 }
97
98 public void setStart(int start) {
99 this.start = start;
100 }
101
102 public boolean isCreateTable() {
103 return createTable;
104 }
105
106 public void setCreateTable(boolean createTable) {
107 this.createTable = createTable;
108 }
109
110 public String getPkConstraint() {
111 return pkConstraint;
112 }
113
114 public void setPkConstraint(String pkConstraint) {
115 this.pkConstraint = pkConstraint;
116 }
117 }
118
119
122 public static class Factory implements JdbcKeyGeneratorFactory{
123
124
128 public Object createArgsBean() {
129 return new Args();
130 }
131
132
136 public JdbcKeyGenerator createJdbcKeyGenerator(String className,
137 JdbcTable classTable, Object args) {
138 HighLowJdbcKeyGenerator kg = new HighLowJdbcKeyGenerator(
139 classTable, (Args)args);
140 return kg;
141 }
142 }
143
144 protected JdbcTable classTable;
145 protected JdbcColumn classPk;
146 protected int pkJavaTypeCode;
147
148 protected String tableName;
149 protected String keyColumnName;
150 protected String valueColumnName;
151 protected int keyColumnLength;
152 protected int grabSize;
153 protected int start;
154 protected boolean createTable;
155 protected String pkConstraint;
156
157 protected String updateSql;
158 protected String selectSql;
159 protected int lastUsed;
160 protected int grabLeft;
161
162 public HighLowJdbcKeyGenerator(JdbcTable classTable, Args args) {
163 if (classTable.pk.length > 1) {
164 throw new IllegalArgumentException ("Cannot use HIGH/LOW key generator on a table with multiple " +
165 "primary key columns");
166 }
167 this.classTable = classTable;
168 classPk = classTable.pk[0];
169 pkJavaTypeCode = classPk.javaTypeCode;
170 tableName = args.getTableName();
171 keyColumnName = args.getKeyColumnName();
172 valueColumnName = args.getValueColumnName();
173 keyColumnLength = args.getKeyColumnLength();
174 grabSize = args.getGrabSize();
175 start = args.getStart();
176 createTable = args.isCreateTable();
177 pkConstraint = args.getPkConstraint();
178 }
179
180
193 public void init(String className, JdbcTable classTable,
194 Connection con) throws SQLException {
195
196 String where = " where " + keyColumnName + " = '" + classTable.name + "'";
198 updateSql = "update " + tableName + " set " + valueColumnName +
199 " = " + valueColumnName + " + ?" +
200 where;
201 selectSql = "select " + valueColumnName + " from " + tableName +
202 where;
203
204 Statement stat = null;
206 PreparedStatement ps = null;
207 try {
208 ps = con.prepareStatement(updateSql);
209 ps.setInt(1, 0);
210 if (ps.executeUpdate() == 0) {
211 stat = con.createStatement();
212 int first = start;
213 if (first == 0) {
214 String sql =
215 "select max(" + classPk.name + ") from " + classTable.name;
216 ResultSet rs = null;
217 try {
218 rs = stat.executeQuery(sql);
219 rs.next();
220 first = rs.getInt(1);
221 } finally {
222 cleanup(rs);
223 }
224 }
225 String sql =
226 "insert into " + tableName + " (" + keyColumnName + ", " +
227 valueColumnName + ") values ('" + classTable.name + "', " +
228 first + ")";
229 stat.execute(sql);
230 }
231 } finally {
232 cleanup(ps);
233 cleanup(stat);
234 }
235 }
236
237
242 public boolean isPostInsertGenerator() {
243 return false;
244 }
245
246
251 public boolean isRequiresOwnConnection() {
252 return grabSize > 1 && grabLeft == 0;
253 }
254
255
263 public void addKeyGenTables(HashSet set, JdbcMetaDataBuilder mdb) {
264 if (!createTable) return;
265
266 for (Iterator i = set.iterator(); i.hasNext();) {
268 JdbcTable t = (JdbcTable)i.next();
269 if (t.name.equals(tableName)) return;
270 }
271
272 JdbcTable t = new JdbcTable();
274 t.sqlDriver = mdb.getSqlDriver();
275 t.name = tableName;
276 t.comment = getClass().getName();
277 t.pkConstraintName = pkConstraint == null ? "pk_" + tableName : pkConstraint;
278 JdbcMappingResolver mr = mdb.getMappingResolver();
279 JdbcColumn keyCol = new JdbcColumn(mr.resolveMapping(String .class), mr);
280 keyCol.name = keyColumnName;
281 keyCol.length = keyColumnLength;
282 keyCol.nulls = false;
283 JdbcColumn valueCol =
284 new JdbcColumn(mr.resolveMapping(Integer.TYPE), mr);
285
286 valueCol.name = valueColumnName;
287 valueCol.nulls = false;
288 t.cols = new JdbcColumn[]{keyCol, valueCol};
289 t.setPk(new JdbcColumn[]{keyCol});
290 set.add(t);
291 }
292
293
313 public synchronized void generatePrimaryKeyPre(String className,
314 JdbcTable classTable, int newObjectCount, Object [] data,
315 Connection con)
316 throws SQLException {
317 int pk;
318 if (grabSize == 1) {
319 pk = lookupNewNumber(con, grabSize);
320 } else {
321 if (grabLeft == 0) {
322 int effectiveGrabSize = newObjectCount;
323 if (effectiveGrabSize < grabSize) effectiveGrabSize = grabSize;
324 lastUsed = lookupNewNumber(con, effectiveGrabSize);
325 grabLeft = effectiveGrabSize - 1;
326 } else {
327 --grabLeft;
328 }
329 pk = lastUsed++;
330 }
331 switch (pkJavaTypeCode) {
332 case MDStatics.INTW:
333 case MDStatics.INT:
334 data[0] = new Integer ((int)pk);
335 break;
336 case MDStatics.SHORTW:
337 case MDStatics.SHORT:
338 data[0] = new Short ((short)pk);
339 break;
340 case MDStatics.BYTEW:
341 case MDStatics.BYTE:
342 data[0] = new Byte ((byte)pk);
343 break;
344 case MDStatics.LONGW:
345 case MDStatics.LONG:
346 data[0] = new Long (pk);
347 break;
348 default:
349 throw BindingSupportImpl.getInstance().internal(
350 "Unhandled java type code: " + pkJavaTypeCode);
351 }
352 }
353
354
358 protected int lookupNewNumber(Connection con, int effectiveGrabSize)
359 throws SQLException {
360 PreparedStatement ps = null;
361 try {
362 ps = con.prepareStatement(updateSql);
363 ps.setInt(1, effectiveGrabSize);
364 if (ps.executeUpdate() == 0) {
365 throw BindingSupportImpl.getInstance().fatalDatastore("Row not found in keygen table:\n" +
366 updateSql);
367 }
368 Statement stat = null;
369 ResultSet rs = null;
370 try {
371 stat = con.createStatement();
372 rs = stat.executeQuery(selectSql);
373 rs.next();
374 return rs.getInt(1) - (effectiveGrabSize - 1);
375 } finally {
376 cleanup(rs);
377 cleanup(stat);
378 }
379 } finally {
380 cleanup(ps);
381 }
382 }
383
384 private void cleanup(ResultSet rs) {
385 try {
386 if (rs != null) rs.close();
387 } catch (SQLException e) {
388 }
390 }
391
392 private void cleanup(Statement s) {
393 try {
394 if (s != null) s.close();
395 } catch (SQLException e) {
396 }
398 }
399
400
414 public void generatePrimaryKeyPost(String className,
415 JdbcTable classTable, Object [] data,
416 Connection con, Statement stat) throws SQLException {
417 throw BindingSupportImpl.getInstance().internal("not a postInsertGenerator");
418 }
419
420
426 public String getPostInsertSQLSuffix(JdbcTable classTable) {
427 throw BindingSupportImpl.getInstance().internal("not a postInsertGenerator");
428 }
429
430 }
431 |
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