/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.jackrabbit.core.persistence.pool;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.apache.jackrabbit.core.util.db.ConnectionHelper;
import org.apache.jackrabbit.core.util.db.DbUtility;
/**
* Same as {@link DbNameIndex} but does not make use of the
* {@link java.sql.Statement#RETURN_GENERATED_KEYS} feature as it is not
* provided by the underlying database driver for PostgreSQL.
*/
public class PostgreSQLNameIndex extends DbNameIndex {
protected String generatedKeySelectSQL;
public PostgreSQLNameIndex(ConnectionHelper connectionHelper, String schemaObjectPrefix)
throws SQLException {
super(connectionHelper, schemaObjectPrefix);
}
/**
* Inits this index and prepares the statements.
*
* @param schemaObjectPrefix the prefix for table names
* @throws SQLException if the statements cannot be prepared.
*/
protected void init(String schemaObjectPrefix)
throws SQLException {
nameSelectSQL = "select NAME from " + schemaObjectPrefix + "NAMES where ID = ?";
indexSelectSQL = "select ID from " + schemaObjectPrefix + "NAMES where NAME = ?";
nameInsertSQL = "insert into " + schemaObjectPrefix + "NAMES (NAME) values (?)";
generatedKeySelectSQL = "select currval('" + schemaObjectPrefix + "NAMES_ID_SEQ')";
}
/**
* Inserts a string into the database and returns the new index.
* <p>
* Instead of using the {@link java.sql.Statement#RETURN_GENERATED_KEYS}
* feature, the newly inserted index is retrieved by a 2nd select statement.
*
* @param string the string to insert
* @return the new index.
*/
protected int insertString(String string) {
// assert index does not exist
try {
conHelper.exec(nameInsertSQL, new Object[]{string});
return getGeneratedKey();
} catch (Exception e) {
IllegalStateException ise = new IllegalStateException("Unable to insert index for string: " + string);
ise.initCause(e);
throw ise;
}
}
/**
* Retrieves the last assigned key from the database.
* @return the index.
*/
protected int getGeneratedKey() {
ResultSet rs = null;
try {
rs = conHelper.exec(generatedKeySelectSQL, null, false, 0);
if (!rs.next()) {
return -1;
} else {
return rs.getInt(1);
}
} catch (Exception e) {
IllegalStateException ise = new IllegalStateException("Unable to read generated index");
ise.initCause(e);
throw ise;
} finally {
DbUtility.close(rs);
}
}
}