org.apache.ctakes.jdl.data.base.JdlConnection.java Source code

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Here is the source code for org.apache.ctakes.jdl.data.base.JdlConnection.java

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/**
 * 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.ctakes.jdl.data.base;

import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;

import org.apache.commons.lang.StringUtils;
import org.apache.ctakes.jdl.schema.xdl.JdbcType;

/**
 * Connection with db.
 * 
 * @author mas
 */
public class JdlConnection {
    private String driver;
    private String url;
    private String user;
    private String password;
    private Connection connection;

    /**
     * @param jdbc
     *            the jdbc
     */
    public JdlConnection(final JdbcType jdbc) {
        driver = StringUtils.defaultIfEmpty(jdbc.getDriver(), driver);
        url = StringUtils.defaultIfEmpty(jdbc.getUrl(), url);
        user = StringUtils.defaultIfEmpty(jdbc.getUsername(), user);
        password = StringUtils.defaultIfEmpty(jdbc.getPassword(), password);
    }

    /**
     * @return the connected
     * @throws SQLException
     *             exception
     */
    public final boolean isConnected() throws SQLException {
        return (connection != null && !connection.isClosed());
    }

    /**
     * Attempts to establish a connection.
     * 
     * @throws InstantiationException
     *             exception
     * @throws IllegalAccessException
     *             exception
     * @throws ClassNotFoundException
     *             exception
     * @throws SQLException
     *             exception
     */
    private void openConnection()
            throws InstantiationException, IllegalAccessException, ClassNotFoundException, SQLException {
        // Class.forName(driver);
        DriverManager.registerDriver((Driver) Class.forName(driver).newInstance());
        connection = DriverManager.getConnection(url, user, password);
    }

    /**
     * @return the openConnection
     * @throws InstantiationException
     *             exception
     * @throws IllegalAccessException
     *             exception
     * @throws ClassNotFoundException
     *             exception
     * @throws SQLException
     *             exception
     */
    public final Connection getOpenConnection()
            throws InstantiationException, IllegalAccessException, ClassNotFoundException, SQLException {
        if (!isConnected()) {
            openConnection();
        }
        return connection;
    }

    /**
     * Makes all changes made since the previous commit/rollback permanent and
     * releases any database locks currently held by this Connection object.
     * 
     * @throws SQLException
     *             exception
     */
    public final void commitConnection() throws SQLException {
        if (isConnected() && !connection.getAutoCommit()) {
            connection.commit();
        }
    }

    /**
     * Undoes all changes made in the current transaction and releases any
     * database locks currently held by this Connection object.
     * 
     * @throws SQLException
     *             exception
     */
    public final void rollbackConnection() throws SQLException {
        if (isConnected() && !connection.getAutoCommit()) {
            connection.rollback();
        }
    }

    /**
     * Releases this Connection object's database.
     * 
     * @throws SQLException
     *             exception
     */
    public final void closeConnection() throws SQLException {
        if (isConnected()) {
            connection.close();
        }
    }

    /**
     * @return the autoCommit
     * @throws SQLException
     *             exception
     */
    public final boolean isAutoCommit() throws SQLException {
        return (isConnected()) ? connection.getAutoCommit() : false;
    }

    /**
     * @param autoCommit
     *            the autoCommit to set
     * @throws SQLException
     *             exception
     */
    public final void setAutoCommit(final boolean autoCommit) throws SQLException {
        if (isConnected()) {
            connection.setAutoCommit(autoCommit);
        }
    }
}