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1
28
29 package com.caucho.amber.idgen;
30
31 import com.caucho.amber.manager.AmberConnection;
32 import com.caucho.amber.manager.AmberPersistenceUnit;
33 import com.caucho.config.ConfigException;
34 import com.caucho.jdbc.JdbcMetaData;
35 import com.caucho.util.L10N;
36 import com.caucho.util.Log;
37
38 import javax.sql.DataSource  ;
39 import java.sql.Connection ;
40 import java.sql.PreparedStatement ;
41 import java.sql.ResultSet ;
42 import java.sql.SQLException ;
43 import java.sql.Statement ;
44 import java.util.logging.Level ;
45 import java.util.logging.Logger ;
46
47
50 public class SequenceIdGenerator extends IdGenerator {
51 private static final L10N L = new L10N(SequenceIdGenerator.class);
52 private static final Logger log = Log.open(SequenceIdGenerator.class);
53
54 private AmberPersistenceUnit _manager;
55 private String _name;
56 private int _size;
57
58 private String _selectSQL;
59
60 private boolean _isInit;
61
62
65 public SequenceIdGenerator(AmberPersistenceUnit manager,
66 String name,
67 int size)
68 throws ConfigException
69 {
70 _manager = manager;
71 _name = name;
72 _size = size;
73 }
74
75
78 public long allocateGroup(AmberConnection aConn)
79 throws SQLException
80 {
81 Connection conn = aConn.getConnection();
83
84 PreparedStatement selectStmt = conn.prepareStatement(_selectSQL);
85
86 long value = -1;
87
88 ResultSet rs = selectStmt.executeQuery();
89 if (rs.next())
90 value = rs.getLong(1);
91
92 rs.close();
93
94 return value;
95 }
96
97
100 public void init(AmberPersistenceUnit amberPersistenceUnit)
101 throws SQLException
102 {
103 if (_isInit)
104 return;
105 _isInit = true;
106
107 DataSource ds = amberPersistenceUnit.getDataSource();
108 Connection conn = ds.getConnection();
109 try {
110 JdbcMetaData metaData = amberPersistenceUnit.getMetaData();
111
112 _selectSQL = metaData.selectSequenceSQL(_name);
113
114 if (amberPersistenceUnit.getCreateDatabaseTables()) {
115 String sql = metaData.createSequenceSQL(_name, getGroupSize());
116
117 try {
118 Statement stmt = conn.createStatement();
119 stmt.executeUpdate(sql);
120 stmt.close();
121 } catch (Exception e) {
122 log.log(Level.FINER, e.toString(), e);
123 }
124 }
125 } finally {
126 conn.close();
127 }
128 }
129 }
130 |
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