| /**************************************************************** |
| * 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.james.ai.classic; |
| |
| import java.sql.Connection; |
| import java.sql.DatabaseMetaData; |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| import java.sql.Statement; |
| import java.util.Locale; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * <p> |
| * Helper class for managing common JDBC tasks. |
| * </p> |
| * |
| * <p> |
| * This class is abstract to allow implementations to take advantage of |
| * different logging capabilities/interfaces in different parts of the code. |
| * </p> |
| */ |
| final class JDBCUtil { |
| private static final Logger LOGGER = LoggerFactory.getLogger(JDBCUtil.class); |
| |
| public JDBCUtil() { |
| super(); |
| } |
| |
| /** |
| * Checks database metadata to see if a table exists. Try UPPER, lower, and |
| * MixedCase, to see if the table is there. |
| * |
| * @param dbMetaData |
| * the database metadata to be used to look up this table |
| * @param tableName |
| * the table name |
| * |
| * @throws SQLException |
| * if an exception is encountered while accessing the database |
| */ |
| public boolean tableExists(DatabaseMetaData dbMetaData, String tableName) throws SQLException { |
| return (tableExistsCaseSensitive(dbMetaData, tableName) || tableExistsCaseSensitive(dbMetaData, tableName.toUpperCase(Locale.US)) || tableExistsCaseSensitive(dbMetaData, tableName.toLowerCase(Locale.US))); |
| } |
| |
| /** |
| * Checks database metadata to see if a table exists. This method is |
| * sensitive to the case of the provided table name. |
| * |
| * @param dbMetaData |
| * the database metadata to be used to look up this table |
| * @param tableName |
| * the case sensitive table name |
| * |
| * @throws SQLException |
| * if an exception is encountered while accessing the database |
| */ |
| public boolean tableExistsCaseSensitive(DatabaseMetaData dbMetaData, String tableName) throws SQLException { |
| ResultSet rsTables = dbMetaData.getTables(null, null, tableName, null); |
| try { |
| return rsTables.next(); |
| } finally { |
| closeJDBCResultSet(rsTables); |
| } |
| } |
| |
| /** |
| * Checks database metadata to see if a column exists in a table. Try UPPER, |
| * lower, and MixedCase, both on the table name and the column name, to see |
| * if the column is there. |
| * |
| * @param dbMetaData |
| * the database metadata to be used to look up this column |
| * @param tableName |
| * the table name |
| * @param columnName |
| * the column name |
| * |
| * @throws SQLException |
| * if an exception is encountered while accessing the database |
| */ |
| public boolean columnExists(DatabaseMetaData dbMetaData, String tableName, String columnName) throws SQLException { |
| return (columnExistsCaseSensitive(dbMetaData, tableName, columnName) || columnExistsCaseSensitive(dbMetaData, tableName, columnName.toUpperCase(Locale.US)) || columnExistsCaseSensitive(dbMetaData, tableName, columnName.toLowerCase(Locale.US)) |
| || columnExistsCaseSensitive(dbMetaData, tableName.toUpperCase(Locale.US), columnName) || columnExistsCaseSensitive(dbMetaData, tableName.toUpperCase(Locale.US), columnName.toUpperCase(Locale.US)) |
| || columnExistsCaseSensitive(dbMetaData, tableName.toUpperCase(Locale.US), columnName.toLowerCase(Locale.US)) || columnExistsCaseSensitive(dbMetaData, tableName.toLowerCase(Locale.US), columnName) |
| || columnExistsCaseSensitive(dbMetaData, tableName.toLowerCase(Locale.US), columnName.toUpperCase(Locale.US)) || columnExistsCaseSensitive(dbMetaData, tableName.toLowerCase(Locale.US), columnName.toLowerCase(Locale.US))); |
| } |
| |
| /** |
| * Checks database metadata to see if a column exists in a table. This |
| * method is sensitive to the case of both the provided table name and |
| * column name. |
| * |
| * @param dbMetaData |
| * the database metadata to be used to look up this column |
| * @param tableName |
| * the case sensitive table name |
| * @param columnName |
| * the case sensitive column name |
| * |
| * @throws SQLException |
| * if an exception is encountered while accessing the database |
| */ |
| public boolean columnExistsCaseSensitive(DatabaseMetaData dbMetaData, String tableName, String columnName) throws SQLException { |
| ResultSet rsTables = dbMetaData.getColumns(null, null, tableName, columnName); |
| try { |
| return rsTables.next(); |
| } finally { |
| closeJDBCResultSet(rsTables); |
| } |
| } |
| |
| /** |
| * Closes database connection and logs if an error is encountered |
| * |
| * @param conn |
| * the connection to be closed |
| */ |
| public void closeJDBCConnection(Connection conn) { |
| try { |
| if (conn != null) { |
| conn.close(); |
| } |
| } catch (SQLException sqle) { |
| // Log exception and continue |
| LOGGER.error("Unexpected exception while closing database connection.", sqle); |
| } |
| } |
| |
| /** |
| * Closes database statement and logs if an error is encountered |
| * |
| * @param stmt |
| * the statement to be closed |
| */ |
| public void closeJDBCStatement(Statement stmt) { |
| try { |
| if (stmt != null) { |
| stmt.close(); |
| } |
| } catch (SQLException sqle) { |
| // Log exception and continue |
| LOGGER.error("Unexpected exception while closing database statement.", sqle); |
| } |
| } |
| |
| /** |
| * Closes database result set and logs if an error is encountered |
| * |
| * @param aResultSet |
| * the result set to be closed |
| */ |
| public void closeJDBCResultSet(ResultSet aResultSet) { |
| try { |
| if (aResultSet != null) { |
| aResultSet.close(); |
| } |
| } catch (SQLException sqle) { |
| // Log exception and continue |
| LOGGER.error("Unexpected exception while closing database result set.", sqle); |
| } |
| } |
| |
| } |