Mega Code Archive
Encapsulate the Connection-related operations that every JDBC program seems to use
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/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
/** Encapsulate the Connection-related operations that every
* JDBC program seems to use.
*/
public class ConnectionUtil {
/** The default config filename, relative to ${user.home} */
public static final String DEFAULT_NAME = ".db.properties";
/** The current config filename */
private static String configFileName =
System.getProperty("user.home") + File.separator + DEFAULT_NAME;
/** Get a Connection for the given config using the default or set property file name */
public static Connection getConnection(String config) throws Exception {
try {
Properties p = new Properties();
p.load(new FileInputStream(configFileName));
return getConnection(p, config);
} catch (IOException ex) {
throw new Exception(ex.toString());
}
}
/** Get a Connection for the given config name from a provided Properties */
public static Connection getConnection(Properties p, String config) throws Exception {
try {
String db_driver = p.getProperty(config + "." + "DBDriver");
String db_url = p.getProperty(config + "." + "DBURL");
String db_user = p.getProperty(config + "." + "DBUser");
String db_password = p.getProperty(config + "." + "DBPassword");
if (db_driver == null || db_url == null) {
throw new IllegalStateException("Driver or URL null: " + config);
}
return createConnection(db_driver, db_url, db_user, db_password);
} catch (ClassNotFoundException ex) {
throw new Exception(ex.toString());
} catch (SQLException ex) {
throw new Exception(ex.toString());
}
}
public static Connection createConnection(String db_driver, String db_url,
String db_user, String db_password)
throws ClassNotFoundException, SQLException {
// Load the database driver
System.out.println("Loading driver " + db_driver);
Class.forName(db_driver);
System.out.println("Connecting to DB " + db_url);
return DriverManager.getConnection(
db_url, db_user, db_password);
}
/** Returns the full path of the configuration file being used.
* @return Returns the configFileName.
*/
public static String getConfigFileName() {
return configFileName;
}
/** Sets the full path of the config file to read.
* @param configFileNam The FileName of the configuration file to use.
*/
public static void setConfigFileName(String configFileNam) {
configFileName = configFileNam;
File file = new File(configFileName);
if (!file.canRead()) {
throw new IllegalArgumentException("Unreadable: " + configFileName);
}
try {
ConnectionUtil.configFileName = file.getCanonicalPath();
} catch (IOException ex) {
System.err.println("Warning: IO error checking path: " + configFileName);
ConnectionUtil.configFileName = configFileName;
}
}
}
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