1. 程式人生 > 其它 >JDBC 筆記02(獲取資料庫連線)

JDBC 筆記02(獲取資料庫連線)

技術標籤:jdbc資料庫jdbcjava資料庫

連線的方式一

    @Test
    public void testConnection_01() throws SQLException {

        Driver driver = new com.mysql.jdbc.Driver();

        //url = 協議://ip地址:埠號/資料庫
        String url = "jdbc:mysql://localhost:3306/mysupermarket";
        //將使用者名稱和密碼封裝在Properties中
        Properties info =
new Properties(); info.setProperty("user","root"); info.setProperty("password","123456"); Connection connect = driver.connect(url, info); System.out.println(connect); }

連線的方式二(對方式一的迭代)

    @Test
    public void testConnection_02
() throws Exception { //1、獲取Driver實現類物件(反射) Class aClass = Class.forName("com.mysql.jdbc.Driver"); Driver driver = (Driver) aClass.newInstance(); //2、提供要連線的資料庫 String url = "jdbc:mysql://localhost:3306/mysupermarket"; //3、提供連線需要的使用者名稱和密碼 Properties info =
new Properties(); info.setProperty("user","root"); info.setProperty("password","123456"); //4、獲取連線 Connection connect = driver.connect(url, info); System.out.println(connect); }

連線的方式三

    @Test
    public void testConnection_03() throws Exception{
        //1、獲取Driver實現類物件(反射)
        Class aClass = Class.forName("com.mysql.jdbc.Driver");
        Driver driver = (Driver) aClass.newInstance();

        //2、提供需要的3個基本資訊
        String url = "jdbc:mysql://localhost:3306/mysupermarket";
        String user = "root";
        String password = "123456";

        //3、註冊驅動
        DriverManager.registerDriver(driver);
        //4、獲取連線
        Connection connection = DriverManager.getConnection(url, user, password);

        System.out.println(connection);
    }

連線的方式四(方式三的優化)

@Test
    public void testConnection_04() throws Exception{
        //1、提供需要的3個基本資訊
        String url = "jdbc:mysql://localhost:3306/mysupermarket";
        String user = "root";
        String password = "123456";

        //2、載入Driver
        Class.forName("com.mysql.jdbc.Driver");

        /*
        * 省略了驅動的註冊,
        * 因為在mysql的Driver實現類中宣告的
        * static{
        *     try{
        *         java.aql.DriverManager.registerDriver(new driver);
        *     }
        *     catch{
        *         、、、、、、
        *     }
        * }
        * 語句塊自動註冊了驅動。
        * */

        //3、獲取連線
        Connection connection = DriverManager.getConnection(url, user, password);

        System.out.println(connection);
    }

連線的方式五(最終版)

  • 使用配置檔案讀取獲取連線需要的4個基本資訊:

配置檔案程式碼如下:

user=root
password=azhu251264
url=jdbc:mysql://localhost:3306/mysupermarket
driverClass=com.mysql.jdbc.Driver
    @Test
    public void testConnection_05() throws Exception{
        //1、讀取配置檔案
        InputStream inputStream = ConnectionTest_01.class.getClassLoader().
            getResourceAsStream("jdbc.properties");

        Properties properties = new Properties();
        properties.load(inputStream);

        String user = properties.getProperty("user");
        String password = properties.getProperty("password");
        String url = properties.getProperty("url");
        String driverClass = properties.getProperty("driverClass");

        //2、載入驅動
        Class.forName(driverClass);

        //3、獲取連線
        Connection connection = DriverManager.getConnection(url,user,password);

        System.out.println(connection);

    }