以mysql数据库为例

1、加载驱动

public class TestDatabase {
	public static void main(String[] args) {
		try {
			Class.forName("com.mysql.jdbc.Driver");
			System.out.println("加载驱动成功");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}
}

加载驱动成功

或者：

public class TestDatabase {
     private static String dbname="com.mysql.jdbc.Driver";
	public static void main(String[] args) {
		try {
			Class.forName("dbname");
			System.out.println("加载驱动成功");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}

	}
}







数据库连接


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class TestDatabase {
	public static void main(String[] args) {
		Connection con=null;
		try {
			Class.forName("com.mysql.jdbc.Driver");
			String url="jdbc:mysql://localhost:3306/school";
			con=DriverManager.getConnection(url,"root","123456");
			System.out.println("数据库连接成功");
			System.out.println("加载驱动成功");
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			try {
				con.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

	}
}



运行结果


数据库连接成功
加载驱动成功


或者：


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class TestDatabase {
     private static String dbname="com.mysql.jdbc.Driver";
     private static String dburl="jdbc:mysql://localhost:3306/school";
     private static String username="root";
     private static String password="123456";
     
	public static void main(String[] args) {
		Connection con=null;
		try {
			Class.forName(dbname);
			con=DriverManager.getConnection(dburl,username,password);
			System.out.println("数据库连接成功");
			System.out.println("加载驱动成功");
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			try {
				con.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

	}
}



或者（不建议使用）：


import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Properties;

public class TestDatabase {
	public static void main(String[] args) {
		try {
			Properties p=new Properties();
			InputStream in=new FileInputStream("./src/db.properties");
			p.load(in);
			System.out.println("数据库连接成功");
			System.out.println("加载驱动成功");
		} catch (Exception e) {
			e.printStackTrace();
		}

	}
}





db.properties


driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/school
name=root
password=123456





在或者（建议使用）


import java.io.InputStream;
import java.util.Properties;

public class TestDatabase {
	public static void main(String[] args) {
		try {
			Properties p=new Properties();
			//获取程序运行环境的类加载器,默认加载src根目录的文件信息
        ClassLoader loader=TestDatabase.class.getClassLoader();
         InputStream in=loader.getResourceAsStream("db.properties");
			p.load(in);
			System.out.println("数据库连接成功");
			System.out.println("加载驱动成功");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}




工程目录


JDBC