/*
* Copyright 2009 Ahmad Hassan, 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.
*/
package org.castor.cpa.persistence.sql.keygen;
import java.sql.Connection;
import java.sql.CallableStatement;
import java.sql.SQLException;
import java.text.MessageFormat;
import java.util.Properties;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.exolab.castor.jdo.PersistenceException;
import org.castor.core.util.Messages;
import org.exolab.castor.mapping.MappingException;
import org.exolab.castor.persist.spi.PersistenceFactory;
import org.exolab.castor.jdo.Database;
import org.exolab.castor.jdo.engine.SQLColumnInfo;
import org.exolab.castor.jdo.engine.SQLEngine;
import org.exolab.castor.jdo.engine.SQLFieldInfo;
import org.exolab.castor.jdo.engine.nature.ClassDescriptorJDONature;
import org.castor.cpa.persistence.sql.engine.CastorConnection;
import org.castor.cpa.persistence.sql.engine.CastorStatement;
import org.castor.cpa.persistence.sql.query.Insert;
import org.castor.cpa.persistence.sql.query.expression.Column;
import org.castor.cpa.persistence.sql.query.expression.NextVal;
import org.castor.cpa.persistence.sql.query.expression.Parameter;
import org.castor.persist.ProposedEntity;
import org.exolab.castor.mapping.ClassDescriptor;
import org.exolab.castor.persist.spi.Identity;
/**
* Implements methods specific to Sequence During Key generator. It invovles the
* ID generation while constructing the sql statement.
*
* @author <a href="mailto:ahmad DOT hassan AT gmail DOT com">Ahmad Hassan</a>
* @author <a href="mailto:ralf DOT joachim AT syscon DOT eu">Ralf Joachim</a>
* @version $Revision$ $Date: 2009-07-13 17:22:43 (Tue, 28 Jul 2009) $
*/
public final class SequenceDuringKeyGenerator extends AbstractKeyGenerator {
//-----------------------------------------------------------------------------------
/** 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(SequenceDuringKeyGenerator.class);
/** Persistence factory for the database engine the entity is persisted in.
* Used to format the SQL statement. */
private PersistenceFactory _factory;
/** True if trigger is present for specific database engien. */
private boolean _triggerPresent;
/** Sequence name associated with the table. */
private String _seqName;
/** SQL engine for all persistence operations at entities of the type this
* class is responsible for. Holds all required information of the entity type. */
private SQLEngine _engine;
/** Name of the Table extracted from Class descriptor. */
private String _mapTo;
/** Represents the engine type obtained from clas descriptor. */
private String _engineType = null;
/** Variable to store built insert class hierarchy. */
private Insert _insert;
//-----------------------------------------------------------------------------------
/**
* Initialize the SEQUENCE key generator for DURING_INSERT style
* {@link #generateKey} is never called.
*
* @param factory A PersistenceFactory instance.
* @param params Database engine specific properties.
* @param sqlType A SQLTypidentifier.
* @throws MappingException if this key generator is not compatible with the
* persistance factory.
*/
public SequenceDuringKeyGenerator(final PersistenceFactory factory, final Properties params,
final int sqlType) throws MappingException {
_factory = factory;
_triggerPresent = "true".equals(params.getProperty("trigger", "false"));
_seqName = params.getProperty("sequence", "{0}_seq");
}
//-----------------------------------------------------------------------------------
/**
* @param conn An open connection within the given transaction.
* @param tableName The table name.
* @param primKeyName The primary key name.
* @return A new key.
* @throws PersistenceException An error occured talking to persistent storage.
*/
public Object generateKey(final Connection conn, final String tableName,
final String primKeyName) throws PersistenceException {
return null;
}
/**
* {@inheritDoc}
*/
public boolean isInSameConnection() {
return true;
}
/**
* {@inheritDoc}
*/
public KeyGenerator buildStatement(final SQLEngine engine) {
_engine = engine;
ClassDescriptor clsDesc = _engine.getDescriptor();
_engineType = clsDesc.getJavaClass().getName();
_mapTo = new ClassDescriptorJDONature(clsDesc).getTableName();
_insert = new Insert(_mapTo);
// is it right to omit all identities in this case?
// maybe we should support to define a separat keygen
// for every identity or complex/custom keygen that
// supports multiple columns.
SQLFieldInfo[] fields = _engine.getInfo();
for (int i = 0; i < fields.length; ++i) {
if (fields[i].isStore()) {
SQLColumnInfo[] columns = fields[i].getColumnInfo();
for (int j = 0; j < columns.length; j++) {
String name = columns[j].getName();
_insert.addAssignment(new Column(name), new Parameter(name));
}
}
}
SQLColumnInfo[] ids = _engine.getColumnInfoForIdentities();
if (!_triggerPresent) {
_insert.addAssignment(new Column(ids[0].getName()),
new NextVal(getSeqName(_mapTo, ids[0].getName())));
}
return this;
}
/**
* Formats the sequence name using name of the table and ID.
*
* @param tableName Name of the table.
* @param primKeyName ID of the table.
* @return String representing formatted sequence name.
*/
private String getSeqName(final String tableName, final String primKeyName) {
return MessageFormat.format(_seqName, new Object[] {tableName, primKeyName});
}
/**
* {@inheritDoc}
*/
public Object executeStatement(final Database database, final CastorConnection conn,
final Identity identity, final ProposedEntity entity) throws PersistenceException {
Identity internalIdentity = identity;
SQLEngine extended = _engine.getExtends();
CastorStatement stmt = conn.createStatement();
try {
// must create record in the parent table first. all other dependents
// are created afterwards. quick and very dirty hack to try to make
// multiple class on the same table work.
if (extended != null) {
ClassDescriptor extDesc = extended.getDescriptor();
if (!new ClassDescriptorJDONature(extDesc).getTableName().equals(_mapTo)) {
internalIdentity = extended.create(database, conn.getConnection(), entity,
internalIdentity);
}
}
SQLColumnInfo[] ids = _engine.getColumnInfoForIdentities();
stmt.prepareStatement(_insert);
String statement = stmt.toString();
statement += " RETURNING ";
statement += _factory.quoteName(ids[0].getName());
statement += " INTO ?";
statement = "{call " + statement + "}";
stmt.setStatement(conn.getConnection().prepareCall(statement));
if (LOG.isTraceEnabled()) {
LOG.trace(Messages.format("jdo.creating", _engineType, stmt.toString()));
}
bindFields(entity, stmt);
if (LOG.isTraceEnabled()) {
LOG.trace(Messages.format("jdo.creating", _engineType, stmt.toString()));
}
// generate key during INSERT.
CallableStatement cstmt = (CallableStatement) stmt.getStatement();
int sqlType = ids[0].getSqlType();
cstmt.registerOutParameter(stmt.getParameterSize() + 1, sqlType);
if (LOG.isDebugEnabled()) {
LOG.debug(Messages.format("jdo.creating", _engineType, cstmt.toString()));
}
cstmt.execute();
// first skip all results "for maximum portability"
// as proposed in CallableStatement javadocs.
while (cstmt.getMoreResults() || (cstmt.getUpdateCount() != -1)) {
// no code to execute
}
// identity is returned in the last parameter.
// workaround for INTEGER type in Oracle getObject returns BigDecimal.
Object temp;
if (sqlType == java.sql.Types.INTEGER) {
temp = new Integer(cstmt.getInt(stmt.getParameterSize() + 1));
} else {
temp = cstmt.getObject(stmt.getParameterSize() + 1);
}
internalIdentity = new Identity(ids[0].toJava(temp));
cstmt.close();
stmt.close();
return internalIdentity;
} catch (SQLException except) {
LOG.fatal(Messages.format("jdo.storeFatal", _engineType, stmt.toString()), except);
try {
if (stmt != null) { stmt.close(); }
} catch (SQLException except2) {
LOG.warn("Problem closing JDBC statement", except2);
}
throw new PersistenceException(Messages.format("persist.nested", except), except);
}
}
/**
* Binds parameters values to the PreparedStatement.
*
* @param entity Entity instance from which field values to be fetached to
* bind with sql insert statement.
* @param stmt CastorStatement containing Connection and PersistenceFactory.
* @throws SQLException If a database access error occurs.
* @throws PersistenceException If identity size mismatches.
*/
private void bindFields(final ProposedEntity entity, final CastorStatement stmt
) throws SQLException, PersistenceException {
SQLFieldInfo[] fields = _engine.getInfo();
for (int i = 0; i < fields.length; ++i) {
SQLColumnInfo[] columns = fields[i].getColumnInfo();
if (fields[i].isStore()) {
Object value = entity.getField(i);
if (value == null) {
for (int j = 0; j < columns.length; j++) {
stmt.bindParameter(columns[j].getName(), null, columns[j].getSqlType());
}
} else if (value instanceof Identity) {
Identity identity = (Identity) value;
if (identity.size() != columns.length) {
throw new PersistenceException("Size of identity field mismatch!");
}
for (int j = 0; j < columns.length; j++) {
stmt.bindParameter(columns[j].getName(), columns[j].toSQL(identity.get(j)),
columns[j].getSqlType());
}
} else {
if (columns.length != 1) {
throw new PersistenceException("Complex field expected!");
}
stmt.bindParameter(columns[0].getName(), columns[0].toSQL(value),
columns[0].getSqlType());
}
}
}
}
//-----------------------------------------------------------------------------------
}