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1
29
30 package com.caucho.amber.idgen;
31
32 import com.caucho.amber.manager.AmberConnection;
33 import com.caucho.amber.manager.AmberPersistenceUnit;
34 import com.caucho.amber.type.GeneratorTableType;
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.Logger ;
45
46
49 public class AmberTableGenerator extends IdGenerator {
50 private static final L10N L = new L10N(AmberTableGenerator.class);
51 private static final Logger log = Log.open(AmberTableGenerator.class);
52
53 private AmberPersistenceUnit _manager;
54 private GeneratorTableType _table;
55 private String _name;
56
57 private String _selectSQL;
58 private String _updateSQL;
59
60 private boolean _isInit;
61
62
65 public AmberTableGenerator(AmberPersistenceUnit manager,
66 GeneratorTableType table,
67 String name)
68 {
69 _manager = manager;
70 _table = table;
71 _name = name;
72 }
73
74
77 public long allocateGroup(AmberConnection aConn)
78 throws SQLException
79 {
80 int groupSize = getGroupSize();
81
82 int retry = 5;
83
84 Connection conn = aConn.getConnection();
86 PreparedStatement selectStmt = conn.prepareStatement(_selectSQL);
87 PreparedStatement updateStmt = conn.prepareStatement(_updateSQL);
88
89 selectStmt.setString(1, _name);
90 updateStmt.setString(2, _name);
91
92 while (retry-- > 0) {
93 ResultSet rs = selectStmt.executeQuery();
94 if (rs.next()) {
95 long value = rs.getLong(1);
96 rs.close();
97
98 updateStmt.setLong(1, value + groupSize);
99 updateStmt.setLong(3, value);
100
101 if (updateStmt.executeUpdate() == 1)
102 return value;
103 }
104 rs.close();
105 }
106
107 throw new SQLException (L.l("Can't allocate id from table '{0}'",
108 _table.getTable().getName()));
109 }
110
111
114 public void init(AmberPersistenceUnit amberPersistenceUnit)
115 throws SQLException
116 {
117 if (_isInit)
118 return;
119 _isInit = true;
120
121 _selectSQL = ("select " + _table.getValueColumn() +
122 " from " + _table.getTable().getName() +
123 " where " + _table.getKeyColumn() + "=?");
124
125 _updateSQL = ("update " + _table.getTable().getName() +
126 " set " + _table.getValueColumn() + "=?" +
127 " where " + _table.getKeyColumn() + "=? " +
128 " and " + _table.getValueColumn() + "=?");
129
130 DataSource ds = amberPersistenceUnit.getDataSource();
131 Connection conn = ds.getConnection();
132 try {
133 try {
134 PreparedStatement pstmt = conn.prepareStatement(_selectSQL);
135
136 pstmt.setString(1, _name);
137
138 ResultSet rs = pstmt.executeQuery();
139 if (rs.next()) {
140 rs.close();
141 return;
142 }
143 } catch (SQLException e) {
144 }
145
146 String sql = ("INSERT INTO " + _table.getTable().getName() + " (" +
147 _table.getKeyColumn() + "," +
148 _table.getValueColumn() + ") VALUES " +
149 "('" + _name + "', 1)");
150
151 Statement stmt = conn.createStatement();
152 stmt.executeUpdate(sql);
153 stmt.close();
154 } finally {
155 conn.close();
156 }
157 }
158 }
159 |
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