JDBC connects to the database

First, connect directly through the Driver interface

/ * obtain 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) through Driver Info.setProperty ("password", password); Connection connection = driver.connect (url, info); return connection;}

Second, connect directly through DriverManager

/ * obtain 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") through DriverManager; Connection connection = DriverManager.getConnection (url, user, password); return connection } / * get 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") by writing parameters in the configuration file Connection connection = DriverManager.getConnection (url, info); return connection;} url=jdbc:mysql:///hdzuser=rootpassword=123456

Third, connect through DBCP data source

Testpublic 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 ();}

Or through the configuration file, BasicDatasourceFactory factory mode

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.propertiesdriverClassName=com.mysql.jdbc.Driverurl=jdbc:mysql:///hdzusername=rootpassword=123456initialSize=5maxActive=10minIdle=5maxWait=5000

Fourth, connect through C3P0 data source

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 1 1 1 1000 10 5com.mysql.jdbc.Driverjdbc:mysql:///hdzroot123456