/*
* Copyright 2006 Assaf Arkin, Thomas Yip, Bruce Snyder, Werner Guttmann, Ralf Joachim
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* $Id: SQLStatementLookup.java 7951 2008-10-09 20:52:17Z wguttmn $
*/
package org.exolab.castor.jdo.engine;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.castor.core.util.Messages;
import org.exolab.castor.jdo.DuplicateIdentityException;
import org.exolab.castor.jdo.PersistenceException;
import org.exolab.castor.jdo.QueryException;
import org.exolab.castor.jdo.engine.nature.ClassDescriptorJDONature;
import org.exolab.castor.mapping.MappingException;
import org.exolab.castor.persist.spi.Identity;
import org.exolab.castor.persist.spi.PersistenceFactory;
import org.exolab.castor.persist.spi.QueryExpression;
public final class SQLStatementLookup {
/** The <a href="http://jakarta.apache.org/commons/logging/">Jakarta
* Commons Logging</a> instance used for all logging. */
private static final Log LOG = LogFactory.getLog(SQLStatementLookup.class);
private final SQLEngine _engine;
private final PersistenceFactory _factory;
private final String _type;
private final String _mapTo;
private String _statement;
public SQLStatementLookup(final SQLEngine engine, final PersistenceFactory factory)
throws MappingException {
_engine = engine;
_factory = factory;
_type = engine.getDescriptor().getJavaClass().getName();
_mapTo = new ClassDescriptorJDONature(engine.getDescriptor()).getTableName();
buildStatement();
}
private void buildStatement() throws MappingException {
try {
SQLColumnInfo[] ids = _engine.getColumnInfoForIdentities();
QueryExpression query = _factory.getQueryExpression();
// initalize lookup query
for (int i = 0; i < ids.length; i++) {
query.addParameter(_mapTo, ids[i].getName(), QueryExpression.OP_EQUALS);
}
_statement = query.getStatement(true);
} catch (QueryException except) {
LOG.warn("Problem building SQL", except);
throw new MappingException(except);
}
}
public Object executeStatement(final Connection conn, final Identity identity)
throws PersistenceException {
SQLColumnInfo[] ids = _engine.getColumnInfoForIdentities();
PreparedStatement stmt = null;
try {
stmt = conn.prepareStatement(_statement);
if (LOG.isDebugEnabled()) {
LOG.debug(Messages.format("jdo.duplicateKeyCheck", _statement));
}
// bind the identity to the preparedStatement
int count = 1;
if (identity.size() != ids.length) {
throw new PersistenceException("Size of identity field mismatched!");
}
for (int i = 0; i < ids.length; i++) {
stmt.setObject(count++, ids[i].toSQL(identity.get(i)));
}
if (stmt.executeQuery().next()) {
stmt.close();
throw new DuplicateIdentityException(Messages.format(
"persist.duplicateIdentity", _type, identity));
}
} catch (SQLException except2) {
// Error at the stage indicates it wasn't a duplicate
// primary key problem. But best if the INSERT error is
// reported, not the SELECT error.
}
try {
// Close the insert/select statement
if (stmt != null) { stmt.close(); }
} catch (SQLException except2) {
LOG.warn("Problem closing JDBC statement", except2);
}
return null;
}
}