package connection;
 
import java.sql.Connection;
import java.sql.Driver;
import java.sql.SQLException;
import java.util.Properties;
 
import org.junit.jupiter.api.Test;
 
public class ConnectionTest {
    @Test
    public void test() throws SQLException {
        //創(chuàng)建Driver實(shí)例
        Driver driver=new com.mysql.cj.jdbc.Driver();
        //獲取要讀取數(shù)據(jù)庫的URL
        String url="jdbc:mysql://localhost:3306/test04_emp";
        //將賬號密碼封裝到Properties對象中
        Properties info=new Properties();
        info.setProperty("user", "root");
        info.setProperty("password", "abc123");
        //通過Driver的對象獲取連接
        Connection connect=driver.connect(url, info);
        //調(diào)用連接的toString()
        System.out.println(connect);
    }
}

@Test
    public void test2() throws Exception {
        //通過反射的方式獲取運(yùn)行時(shí)類
        Class clazz=Class.forName("com.mysql.cj.jdbc.Driver");
        //通過反射的方式創(chuàng)建運(yùn)行時(shí)類對象
        Driver driver=(Driver)clazz.newInstance();
        //獲取URL
        String url="jdbc:mysql://localhost:3306/test04_emp";
        //封裝賬號密碼
        Properties info=new Properties();
        info.setProperty("user", "root");
        info.setProperty("password", "abc123");
        //獲取連接
        Connection connect=driver.connect(url, info);
        System.out.println(connect);
    }

@Test
    public void test3() throws Exception {
        //通過反射的方式獲取Driver對象
        Driver driver=(Driver)Class.forName("com.mysql.cj.jdbc.Driver").newInstance();
        //調(diào)用DriverManager的registerDriver(Driver driver)方法注冊驅(qū)動
        DriverManager.registerDriver(driver);
        //提供賬號、密碼和URL
        String user="root";
        String password="abc123";
        String url="jdbc:mysql://localhost:3306/test04_emp";
        //調(diào)用DriverManager的getConnection()方法來獲取連接
        Connection connect=DriverManager.getConnection(url,user,password);
        System.out.println(connect);
        /*getConnection()還有一種版本：getConnection(String url,Properties info)
         * 可以參考方法一和方法二。
         */
    }

@Test
    public void test4() throws Exception {
        //通過反射將Driver加載到內(nèi)存中
        Class.forName("com.mysql.cj.jdbc.Driver");
        //提供相關(guān)信息
        String user="root";
        String password="abc123";
        String url="jdbc:mysql://localhost:3306/test04_emp";
        //通過getConnection()獲取連接
        Connection connect=DriverManager.getConnection(url,user,password);
        System.out.println(connect);
    }

@Test
    public void test5() throws Exception {
        //通過類加載器創(chuàng)建一個(gè)指向配置文件的流
        InputStream input=ConnectionTest.class.getClassLoader().getResourceAsStream("test.properties");
        //創(chuàng)建Properties對象
        Properties infoProperties=new Properties();
        //以流為參數(shù)調(diào)用load()加載配置文件
        infoProperties.load(input);
        //獲取相關(guān)信息
        String driver=infoProperties.getProperty("driver");
        String url=infoProperties.getProperty("url");
        String user=infoProperties.getProperty("user");
        String password=infoProperties.getProperty("password");
        //加載驅(qū)動
        Class.forName(driver);
        //獲取連接
        Connection connection= DriverManager.getConnection(url, user, password);
        System.out.println(connection);
    }