/*
 * Copyright 2005-2008 Jeremy Haile
 *
 * 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.jsecurity.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * <p>
 * A set of static helper methods for managing JDBC API objects.
 * </p>
 *
 * <p>
 * Some parts of this class were copied from the Spring Framework and then modified.
 * They were copied here to prevent Spring dependencies in the JSecurity core API.
 * </p>
 * 
 * @author Jeremy Haile
 * @since 0.2
 */
public class JdbcUtils {

    /**
     * Commons-logger.
     */
    protected static transient final Log log = LogFactory.getLog(JdbcUtils.class);

    /**
     * Private constructor to prevent instantiation.
     */
    private JdbcUtils() {
    }

    /**
     * Close the given JDBC Connection and ignore any thrown exception.
     * This is useful for typical finally blocks in manual JDBC code.
     *
     * @param connection the JDBC Connection to close (may be <tt>null</tt>)
     */
    public static void closeConnection(Connection connection) {
        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException ex) {
                if( log.isDebugEnabled() ) {
                    log.debug("Could not close JDBC Connection", ex);
                }
            } catch (Throwable ex) {
                if( log.isDebugEnabled() ) {
                    log.debug("Unexpected exception on closing JDBC Connection", ex);
                }
            }
        }
    }

    /**
     * Close the given JDBC Statement and ignore any thrown exception.
     * This is useful for typical finally blocks in manual JDBC code.
     *
     * @param statement the JDBC Statement to close (may be <tt>null</tt>)
     */
    public static void closeStatement(Statement statement) {
        if (statement != null) {
            try {
                statement.close();
            } catch (SQLException ex) {
                if( log.isDebugEnabled() ) {
                    log.debug("Could not close JDBC Statement", ex);
                }
            } catch (Throwable ex) {
                if( log.isDebugEnabled() ) {
                    log.debug("Unexpected exception on closing JDBC Statement", ex);
                }
            }
        }
    }

    /**
     * Close the given JDBC ResultSet and ignore any thrown exception.
     * This is useful for typical finally blocks in manual JDBC code.
     *
     * @param rs the JDBC ResultSet to close (may be <tt>null</tt>)
     */
    public static void closeResultSet(ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException ex) {
                if( log.isDebugEnabled() ) {
                    log.debug("Could not close JDBC ResultSet", ex);
                }
            } catch (Throwable ex) {
                if( log.isDebugEnabled() ) {
                    log.debug("Unexpected exception on closing JDBC ResultSet", ex);
                }
            }
        }
    }

}