package connection;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import org.junit.Test;
public class ConnectionTest {
//方式一
@Test
public void testConnection1() throws SQLException{
//获取Driver实现类对象
Driver driver=new com.mysql.jdbc.Driver();
//jdbc:mysql: 协议
//localhost ip地址
//3306 端口号
//test 数据库名
String url="jdbc:mysql://localhost:3306/test?characterEncoding=utf8";
//将用户名和密码封装在Properties中
Properties info = new Properties();
info.setProperty("user","root");
info.setProperty("password","abc123");
Connection connect = driver.connect(url, info);
System.out.println(connect);
}
//方式二:对方式一的迭代:在如下的程序中不出现第三方的API,使得程序具有更好的移植性
@Test
public void testConnection2() throws Exception{
//1.获取Driver实现类对象:使用反射
Class<?> clazz = Class.forName("com.mysql.jdbc.Driver");
Driver driver = (Driver) clazz.newInstance();
//2.提供要连接的数据库
String url="jdbc:mysql://localhost:3306/test?characterEncoding=utf8";
//3.提供连接需要的用户名和密码
Properties info=new Properties();
info.setProperty("user", "root");
info.setProperty("password", "abc123");
//4.获取连接
Connection connect = driver.connect(url, info);
System.out.println(connect);
}
//方式三:使用DriverManger替换Driver
@Test
public void testConnection3() throws Exception{
//1.获取Driver实现类的对象
Class<?> clazz = Class.forName("com.mysql.jdbc.Driver");
Driver driver = (Driver) clazz.newInstance();
//2.提供另外三个连接的基本信息:
String url="jdbc:mysql://localhost:3306/test?characterEncoding=utf8";
String user="root";
String password="abc123";
//注册驱动
DriverManager.registerDriver(driver);
//获取连接
Connection connection = DriverManager.getConnection(url, user, password);
System.out.println(connection);
}
//方式四:只加载驱动,不再显示的注册驱动
@Test
public void testConnection4() throws Exception{
//1.提供三个连接的基本信息
String url="jdbc:mysql://localhost:3306/test?characterEncoding=utf8";
String user="root";
String password="abc123";
//2.加载Driver
Class.forName("com.mysql.jdbc.Driver");
//3.获取连接
Connection connection = DriverManager.getConnection(url, user, password);
System.out.println(connection);
}
/*
方式五:将数据库连接需要的4个基本信息声明在配置文件中,
通过读取配置文件的方式,获取连接
此种方式的好处?
1.实现了数据与代码的分离,实现了解耦
2.如果需要修改配置文件信息,可以避免程序重新打包
*
*/
@Test
public void getConnection5() throws IOException, ClassNotFoundException, SQLException{
//1.读取配置文件中的4个基本信息
InputStream is = ConnectionTest.class.getClassLoader().getResourceAsStream("jdbc.properties");
Properties pros = new Properties();
pros.load(is);
String user=pros.getProperty("user");
String password=pros.getProperty("password");
String url=pros.getProperty("url");
String driverClass=pros.getProperty("driverClass");
//2.加载驱动
Class.forName(driverClass);
//3.获取连接
Connection connection = DriverManager.getConnection(url, user, password);
System.out.println(connection);
}
}
本文摘自 :https://www.cnblogs.com/