JDBC 连接数据库

一、通过Driver接口直接连接

/**  * 通过Driver获取Connection  * @return  */ public Connection getConnectionByDriver() throws Exception{     String driverClass = "com.mysql.jdbc.Driver";     String url = "jdbc:mysql:///hdz";     String user = "root";     String password = "123456";     Driver driver = new com.mysql.jdbc.Driver();     Properties info = new Properties();     info.setProperty("driverClass", driverClass);     info.setProperty("user", user);     info.setProperty("password", password);     Connection connection = driver.connect(url, info);     return connection; }

二、通过DriverManager直接连接

/**  * 通过DriverManager获取Connection   * @return  * @throws Exception  */ public Connection getConnectionByDriverManager() throws Exception{     String url = "jdbc:mysql:///hdz";     String user = "root";     String password = "123456";     Class.forName("com.mysql.jdbc.Driver");     Connection connection = DriverManager.getConnection(url, user, password);     return connection; }

/**     * 通过把参数写在配置文件的方式获取Connection     * @return     * @throws Exception */ public Connection getConectionByProperties() throws Exception{	InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("jdbc.properties");	Properties info = new Properties();	info.load(inputStream);	String url = info.getProperty("url");	Class.forName("com.mysql.jdbc.Driver");	Connection connection = DriverManager.getConnection(url, info);	return connection; } url=jdbc:mysql:///hdz user=root password=123456

三、通过DBCP数据源连接

@Test public void testDbcp() throws Exception {     final BasicDataSource basicDataSource = new BasicDataSource();     basicDataSource.setDriverClassName("com.mysql.jdbc.Driver");     basicDataSource.setUrl("jdbc:mysql:///hdz");     basicDataSource.setUsername("root");     basicDataSource.setPassword("123456");     basicDataSource.setInitialSize(2);     basicDataSource.setMaxActive(2);     basicDataSource.setMinIdle(2);     basicDataSource.setMaxWait(2000);     Connection connection1 = basicDataSource.getConnection();     System.out.println(connection1);     Connection connection2 = basicDataSource.getConnection();     System.out.println(connection2);     new Thread(){         @Override         public void run() {             Connection connection3;             try {                 connection3 = basicDataSource.getConnection();                 System.out.println(connection3);             } catch (SQLException e) {                 e.printStackTrace();             }         }     }.start();     Thread.sleep(3000);     connection2.close(); }

或者通过配置文件，BasicDatasourceFactory工厂方式

private DbcpDataSource() {     Properties info = new Properties();     InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("dbcp.properties");     try {         info.load(inputStream);         dataSource = BasicDataSourceFactory.createDataSource(info);     } catch (IOException e) {         e.printStackTrace();     } catch (Exception e) {         e.printStackTrace();     } } dbcp.properties driverClassName=com.mysql.jdbc.Driver url=jdbc:mysql:///hdz username=root password=123456 initialSize=5 maxActive=10 minIdle=5 maxWait=5000

四、通过C3P0数据源连接

public class C3p0DataSourceUtils { private DataSource dataSource = null; private static C3p0DataSourceUtils instance = new C3p0DataSourceUtils(); private C3p0DataSourceUtils(){     dataSource = new ComboPooledDataSource("intergalactoApp"); } public static C3p0DataSourceUtils newInstance(){     return instance; } public Connection getConnection() {     try {         return dataSource.getConnection();     } catch (SQLException e) {         e.printStackTrace();     }     return null;     } }

c3p0-config.xml <?xml version="1.0" encoding="UTF-8"?> <c3p0-config>   <!-- This app is massive! -->   <named-config name="intergalactoApp">      <property name="acquireIncrement">1</property>     <property name="initialPoolSize">1</property>     <property name="minPoolSize">1</property>     <property name="maxPoolSize">1</property>     <property name="maxIdleTimeExcessConnections">1000</property>     <!-- intergalactoApp adopts a different approach to configuring statement caching -->     <property name="maxStatements">10</property>      <property name="maxStatementsPerConnection">5</property> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="jdbcUrl">jdbc:mysql:///hdz</property> <property name="user">root</property> <property name="password">123456</property>   </named-config> </c3p0-config>