simpledatasource.java

Mandarax是一个规则引擎的纯Java实现。它支持多类型的事实和基于反映的规则

/*
 * Copyright (C) 1999-2004 <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</a>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
package org.mandarax.examples.db;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

/**
 * The example uses a <code>SimpleDataSource</code> to connect to the database. 
 * Works with the settings loaded from the file <strong>exampledb.properties</strong>.
 * In particular, the driver class name and the database url are configured in this file. 
 * The JDBC driver library needs to be in the classpath.
 * @since 2.2
 * @author <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</A>
 * @version 3.4 <7 March 05>
 */
public class SimpleDataSource implements javax.sql.DataSource , java.io.Serializable {
	private String url = null;
	private String driver = null;
	private String user = null;
	private String password = null;
	/**
	 * Constructor.
	 */
	public SimpleDataSource() {
		super();
		Properties dbProperties = new Properties();
		try {
			dbProperties.load(new FileInputStream("exampledb.properties"));
			url = dbProperties.getProperty("url");
			driver = dbProperties.getProperty("driver");
			user = dbProperties.getProperty("user");
			password = dbProperties.getProperty("password");
		}
		catch (IOException x) {
			System.err.println("Cannot load file with database settings: exampledb.properties");
		}
	}
	/**
	 * Get a database connection.
	 * @return a database connection
	 */
	public java.sql.Connection getConnection() throws java.sql.SQLException {		
		return getConnection(user,password);
	}
	/**
	 * Get a database connection.
	 * @return a database connection
	 * @param userName a user name
	 * @param password a password
	 */
	public java.sql.Connection getConnection(String userName, String password) throws java.sql.SQLException {
		// try to load driver
		try {
			Class.forName(driver);
		}
		catch (Exception x) {
			System.err.println("Driver class not found: " + driver);
		}	
		// get connection	
		return DriverManager.getConnection(url,userName,password);
	}
	/**
	 * Get the login timeout.
	 */
	public int getLoginTimeout() throws SQLException {
		return 1000;
	}
	/**
	 * Get a log writer.
	 * @return a log writer
	 */
	public PrintWriter getLogWriter() throws SQLException {
		return null;
	}
	/**
	 * Set the login timeout.
	 * @param millis the time in milli seconds
	 */
	public void setLoginTimeout(int millis) throws SQLException {}
	/**
	 * Set the log writer.
	 * @param writer a writer
	 */
	public void setLogWriter(PrintWriter writer) throws SQLException {}
	/**
	 * Getter for driver property.
	 * @return the driver class name
	 */
	public String getDriver() {
		return driver;
	}
	/**
	 * Setter for the driver property.
	 * @param value a driver class name
	 */
	public void setDriver(String value) {
		driver = value;
	}
	/**
	 * Getter for user property.
	 * @return the user
	 */
	public String getUser() {
		return user;
	}
	/**
	 * Setter for the user property.
	 * @param value the user
	 */
	public void setUser(String value) {
		user = value;
	}
	/**
	 * Getter for password property.
	 * @return the password
	 */
	public String getPassword() {
		return password;
	}
	/**
	 * Setter for the password property.
	 * @param value the password
	 */
	public void setPassword(String value) {
		password = value;
	}			
	/**
	 * Getter for url property.
	 * @return the database url
	 */
	public String getUrl() {
		return url;
	}
	/**
	 * Setter for the url property.
	 * @param value the database url
	 */
	public void setUrl(String value) {
		url = value;
	}	
}