JDBC连接数据库的几种方法

###JDBC

public class DbUtils {
	private static Connection con = null;
	private static PreparedStatement ps =null;
	private static InputStream in = null;
	/*
	 * 静态代码块连接数据库
	 */
	static{
		/*
		 * 原生的第三方jar包连接数据库
		 * 		mysql-connector-java.jar
		 */
		try {
			/*
			 * 	法一:  ==> 最普通的加载
				Class.forName("com.mysql.jdbc.Driver");
				con= DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "root", "root");
			*/
		
		/*
		 * 	法二:  ==> 配置文件连接数据库(database.properties)
			in = DbUtils.class.getClassLoader().getResourceAsStream("database.properties");
			Properties pro = new Properties();
			pro.load(in);
			Class.forName(pro.getProperty("classDriver"));
			con = DriverManager.getConnection(pro.getProperty("url"),pro.getProperty("user"),pro.getProperty("password"));
		 */
		/*	法三:  ==> DBCP连接池手动连接
			BasicDataSource basicDataSource = new BasicDataSource();
			basicDataSource.setDriverClassName("com.mysql.jdbc.Driver");
			basicDataSource.setUrl("jdbc:mysql://localhost:3306/mydatabase");
			basicDataSource.setUsername("root");
			basicDataSource.setPassword("root");
			con = basicDataSource.getConnection();
		*/
		
		/*
		 * 法四:  ==> DBCP连接池读取配置文件连接数据库(dbcpconfig.properties)
		*/
		in = DbUtils.class.getClassLoader().getResourceAsStream("dbcpconfig.properties");
		Properties pro = new Properties();
		pro.load(in);
		DataSource createDataSource = BasicDataSourceFactory.createDataSource(pro);
		con = createDataSource.getConnection();
		
		/*
		 * 法五:  ==> C3P0连接读取xml文件连接数据库
			ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource();
			con = comboPooledDataSource.getConnection();
		*/
	} catch (Exception e) {
		e.printStackTrace();
	}
}