/*
* Copyright 2006 Le Duc Bao, 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.ddlgen.keygenerator;
import org.castor.ddlgen.DDLWriter;
import org.castor.ddlgen.GeneratorException;
import org.castor.ddlgen.schemaobject.KeyGenerator;
import org.exolab.castor.mapping.xml.KeyGeneratorDef;
import org.exolab.castor.mapping.xml.Param;
/**
* HIGH-LOW key generator will be handled by Castor so no DDL needs to be created. It
* only requires a table to lookup the next values to be used.
*
* @author <a href="mailto:leducbao AT gmail DOT com">Le Duc Bao</a>
* @author <a href="mailto:ralf DOT joachim AT syscon DOT eu">Ralf Joachim</a>
* @version $Revision: 5951 $ $Date: 2006-04-25 16:09:10 -0600 (Tue, 25 Apr 2006) $
* @since 1.1
*/
public final class HighLowKeyGenerator extends KeyGenerator {
//--------------------------------------------------------------------------
/** Name of key generator algorithm. */
public static final String ALGORITHM_NAME = "HIGH-LOW";
/** Parameter that defines the name of the sequence table. */
private static final String PARAM_TABLE_NAME = "table";
/** Parameter that defines the name of the column which contains the table name. */
private static final String PARAM_KEY_COLUMN = "key-column";
/** Parameter that defines the name of the column used to reserve key values. */
private static final String PARAM_VALUE_COLUMN = "value-column";
/** Parameter that defines the number of new keys grabed at a time. */
private static final String PARAM_GRAB_SIZE = "grab-size";
/** Parameter that defines if the same connection should be used to write to the
* sequence table. */
private static final String PARAM_SAME_CONNECTION = "same-connection";
/** Parameter that defines if globally unique keys should be generated. */
private static final String PARAM_GLOBAL_KEYS = "global";
//--------------------------------------------------------------------------
/** Name of the special sequence table. */
private String _tableName;
/** Name of the column which contains table names. */
private String _keyColumn;
/** Name of the column which is used to reserve primary key values. */
private String _valueColumn;
/** Number of new keys the key generator should grab from the sequence table at a
* time. */
private int _grabSize;
/** Shell the same Connection be used for writing to the sequence table. This is
* needed when working in EJB environment, though less efficient. Default to
* "false". */
private boolean _isSameConnection = false;
/** Shell globally unique keys be generated. Defaults to "false". */
private boolean _isGlobal = false;
//--------------------------------------------------------------------------
/**
* Constructor for HIGH-LOW key generator specified by given defintion.
*
* @param definition Key generator definition.
* @throws GeneratorException If grab size parameter can't be parsed as integer.
*/
public HighLowKeyGenerator(final KeyGeneratorDef definition)
throws GeneratorException {
super(ALGORITHM_NAME, definition.getAlias());
Param[] params = definition.getParam();
for (int i = 0; i < params.length; i++) {
String name = params[i].getName();
String value = params[i].getValue();
if (name == null) { continue; }
if (PARAM_TABLE_NAME.equalsIgnoreCase(value)) {
_tableName = value;
} else if (PARAM_KEY_COLUMN.equalsIgnoreCase(value)) {
_keyColumn = value;
} else if (PARAM_VALUE_COLUMN.equalsIgnoreCase(value)) {
_valueColumn = value;
} else if (PARAM_GRAB_SIZE.equalsIgnoreCase(value)) {
try {
_grabSize = Integer.parseInt(value);
} catch (NumberFormatException nfe) {
throw new GeneratorException("Can't parse integer" + value, nfe);
}
} else if (PARAM_SAME_CONNECTION.equalsIgnoreCase(name)) {
_isSameConnection = Boolean.valueOf(value).booleanValue();
} else if (PARAM_GLOBAL_KEYS.equals(name.toLowerCase())) {
_isGlobal = Boolean.valueOf(value).booleanValue();
}
}
}
//--------------------------------------------------------------------------
/**
* Get name of the special sequence table.
*
* @return Name of the special sequence table.
*/
public String getTableName() { return _tableName; }
/**
* Get name of the column which contains table names.
*
* @return Name of the column which contains table names.
*/
public String getKeyColumn() { return _keyColumn; }
/**
* Get name of the column which is used to reserve primary key values.
*
* @return Name of the column which is used to reserve primary key values.
*/
public String getValueColumn() { return _valueColumn; }
/**
* Get number of new keys the key generator should grab from the sequence table at a
* time.
*
* @return Number of new keys the key generator should grab from the sequence table
* at a time.
*/
public int getGrabSize() { return _grabSize; }
/**
* Shell the same Connection be used for writing to the sequence table?
*
* @return If <code>true</code> it uses the same connection t write to the sequence
* table.
*/
public boolean isSameConnection() { return _isSameConnection; }
/**
* Shell globally unique keys be generated?
*
* @return If <code>true</code> globally unique keys are generated.
*/
public boolean isGlobal() { return _isGlobal; }
//--------------------------------------------------------------------------
/**
* {@inheritDoc}
*/
public void toCreateDDL(final DDLWriter writer) { }
/**
* {@inheritDoc}
*/
public void toDropDDL(final DDLWriter writer) { }
//--------------------------------------------------------------------------
}