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1 package org.hibernate.id;
3
4 import java.io.Serializable  ;
5 import java.sql.Connection ;
6 import java.sql.PreparedStatement ;
7 import java.sql.ResultSet ;
8 import java.sql.SQLException ;
9 import java.sql.Types ;
10 import java.util.Properties ;
11
12 import org.apache.commons.logging.Log;
13 import org.apache.commons.logging.LogFactory;
14 import org.hibernate.HibernateException;
15 import org.hibernate.LockMode;
16 import org.hibernate.MappingException;
17 import org.hibernate.dialect.Dialect;
18 import org.hibernate.engine.SessionImplementor;
19 import org.hibernate.engine.TransactionHelper;
20 import org.hibernate.mapping.Table;
21 import org.hibernate.type.Type;
22 import org.hibernate.util.PropertiesHelper;
23
24
54 public class MultipleHiLoPerTableGenerator
55 extends TransactionHelper
56 implements PersistentIdentifierGenerator, Configurable {
57
58 private static final Log log = LogFactory.getLog(MultipleHiLoPerTableGenerator.class);
59
60 public static final String ID_TABLE = "table";
61 public static final String PK_COLUMN_NAME = "primary_key_column";
62 public static final String PK_VALUE_NAME = "primary_key_value";
63 public static final String VALUE_COLUMN_NAME = "value_column";
64 public static final String PK_LENGTH_NAME = "primary_key_length";
65
66 private static final int DEFAULT_PK_LENGTH = 255;
67 public static final String DEFAULT_TABLE = "hibernate_sequences";
68 private static final String DEFAULT_PK_COLUMN = "sequence_name";
69 private static final String DEFAULT_VALUE_COLUMN = "sequence_next_hi_value";
70
71 private String tableName;
72 private String pkColumnName;
73 private String valueColumnName;
74 private String query;
75 private String insert;
76 private String update;
77
78 public static final String MAX_LO = "max_lo";
80
81 private long hi;
82 private int lo;
83 private int maxLo;
84 private Class returnClass;
85 private int keySize;
86
87
88 public String [] sqlCreateStrings(Dialect dialect) throws HibernateException {
89 return new String [] {
90 new StringBuffer ()
91 .append("create table ")
92 .append(tableName)
93 .append(" ( ")
94 .append(pkColumnName)
95 .append(" ")
96 .append( dialect.getTypeName(Types.VARCHAR, keySize, 0, 0) )
97 .append(", ")
98 .append(valueColumnName)
99 .append(" ")
100 .append( dialect.getTypeName(Types.INTEGER) )
101 .append(" ) ")
102 .toString()
103 };
104 }
105
106 public String [] sqlDropStrings(Dialect dialect) throws HibernateException {
107 StringBuffer sqlDropString = new StringBuffer ()
108 .append("drop table ");
109 if ( dialect.supportsIfExistsBeforeTableName() ) sqlDropString.append("if exists ");
110 sqlDropString.append(tableName)
111 .append( dialect.getCascadeConstraintsString() );
112 if ( dialect.supportsIfExistsAfterTableName() ) sqlDropString.append(" if exists");
113 return new String [] { sqlDropString.toString() };
114 }
115
116 public Object generatorKey() {
117 return tableName;
118 }
119
120 public Serializable doWorkInCurrentTransaction(Connection conn, String sql) throws SQLException {
121 int result;
122 int rows;
123 do {
124
128 SQL.debug(query);
130 PreparedStatement qps = conn.prepareStatement(query);
131 PreparedStatement ips = null;
132 try {
133 ResultSet rs = qps.executeQuery();
135 boolean isInitialized = rs.next();
136 if ( !isInitialized ) {
137 result = 0;
138 ips = conn.prepareStatement(insert);
139 ips.setInt(1, result);
141 ips.execute();
142 }
143 else {
144 result = rs.getInt(1);
145 }
146 rs.close();
147 }
148 catch (SQLException sqle) {
149 log.error("could not read or init a hi value", sqle);
150 throw sqle;
151 }
152 finally {
153 if (ips != null) {
154 ips.close();
155 }
156 qps.close();
157 }
158
159 PreparedStatement ups = conn.prepareStatement(update);
161 try {
162 ups.setInt( 1, result + 1 );
163 ups.setInt( 2, result );
164 rows = ups.executeUpdate();
166 }
167 catch (SQLException sqle) {
168 log.error("could not update hi value in: " + tableName, sqle);
169 throw sqle;
170 }
171 finally {
172 ups.close();
173 }
174 }
175 while (rows==0);
176 return new Integer (result);
177 }
178
179 public synchronized Serializable generate(SessionImplementor session, Object obj)
180 throws HibernateException {
181 if (lo>maxLo) {
182 int hival = ( (Integer ) doWorkInNewTransaction(session) ).intValue();
183 lo = (hival == 0) ? 1 : 0;
184 hi = hival * (maxLo+1);
185 log.debug("new hi value: " + hival);
186 }
187
188 return IdentifierGeneratorFactory.createNumber( hi + lo++, returnClass );
189 }
190
191 public void configure(Type type, Properties params, Dialect dialect) throws MappingException {
192 this.tableName = PropertiesHelper.getString(ID_TABLE, params, DEFAULT_TABLE);
193 this.pkColumnName = PropertiesHelper.getString(PK_COLUMN_NAME, params, DEFAULT_PK_COLUMN);
194 this.valueColumnName = PropertiesHelper.getString(VALUE_COLUMN_NAME, params, DEFAULT_VALUE_COLUMN);
195 String schemaName = params.getProperty(SCHEMA);
196 String catalogName = params.getProperty(CATALOG);
197 this.keySize = PropertiesHelper.getInt(PK_LENGTH_NAME, params, DEFAULT_PK_LENGTH);
198 String keyValue = PropertiesHelper.getString(PK_VALUE_NAME, params, params.getProperty(TABLE) );
199
200 if ( tableName.indexOf( dialect.getSchemaSeparator() )<0 ) {
201 tableName = Table.qualify( catalogName, schemaName, tableName, dialect.getSchemaSeparator() );
202 }
203
204 query = "select " +
205 valueColumnName +
206 " from " +
207 dialect.appendLockHint(LockMode.UPGRADE, tableName) +
208 " where " + pkColumnName + " = '" + keyValue + "'" +
209 dialect.getForUpdateString();
210
211 update = "update " +
212 tableName +
213 " set " +
214 valueColumnName +
215 " = ? where " +
216 valueColumnName +
217 " = ? and " +
218 pkColumnName +
219 " = '" +
220 keyValue
221 + "'";
222
223 insert = "insert into " + tableName +
224 "(" + pkColumnName + ", " + valueColumnName + ") " +
225 "values('"+ keyValue +"', ?)";
226
227
228 maxLo = PropertiesHelper.getInt(MAX_LO, params, Short.MAX_VALUE);
230 lo = maxLo + 1; returnClass = type.getReturnedClass();
232 }
233 }
234 |
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