JDBCUtils.java

package jdbc;


import java.sql.*;

public class JDBCUtils {
    /**
     * 加载驱动 并建立数据库连接
     * @return
     * @throws ClassNotFoundException
     * @throws SQLException
     */
    public static Connection getConnection() throws ClassNotFoundException, SQLException {

        Class.forName("com.mysql.cj.jdbc.Driver");
        String url="jdbc:mysql://localhost:3306/demo?useSSL=false";
        String username="root";
        String password="root";
        Connection connection=DriverManager.getConnection(url,username,password);

        return connection;
    }

    /**
     * 关闭数据库连接 释放资源
     * @param statement
     * @param connection
     */
    public static void release(Statement statement, Connection connection) {
        if (statement != null) {
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            statement=null;
        }

        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            connection=null;
        }

    }
    public static void release(Statement statement, Connection connection, ResultSet resultSet) {
        if (resultSet != null) {
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            resultSet=null;
        }
        release(statement, connection);

    }

}

TestJdbc.java

package jdbc;

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

public class TestJdbc {
    public static void main(String[] args) {
        try {
            Connection connection=JDBCUtils.getConnection();
            System.out.println(connection);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

运行效果